CROSS-REFERENCE TO RELATED APPLICATIONS
TECHNICAL FIELD
[0002] This invention relates generally to dehumidification and more particularly to a dehumidifier
with secondary evaporator and condenser coils.
BACKGROUND OF THE INVENTION
[0003] In certain situations, it is desirable to reduce the humidity of air within a structure.
For example, in fire and flood restoration applications, it may be desirable to quickly
remove water from areas of a damaged structure. To accomplish this, one or more portable
dehumidifiers may be placed within the structure to direct dry air toward water-damaged
areas. Current dehumidifiers, however, have proven inefficient in various respects.
SUMMARY OF THE INVENTION
[0004] According to embodiments of the present disclosure, disadvantages and problems associated
with previous systems may be reduced or eliminated.
[0005] In certain embodiments, a dehumidification system includes a compressor, a primary
evaporator, a primary condenser, a secondary evaporator, and a secondary condenser.
The secondary evaporator receives an inlet airflow and outputs a first airflow to
the primary evaporator. The primary evaporator receives the first airflow and outputs
a second airflow to the secondary condenser. The secondary condenser receives the
second airflow and outputs a third airflow to the primary condenser. The primary condenser
receives the third airflow and outputs a dehumidified airflow. The compressor receives
a flow of low temperature, low pressure refrigerant vapor from the primary evaporator
and provides the flow of high temperature, high pressure refrigerant vapor to the
primary condenser.
[0006] Certain embodiments of the present disclosure may provide one or more technical advantages.
For example, certain embodiments include two evaporators, two condensers, and two
metering devices that utilize a closed refrigeration loop. This configuration causes
part of the refrigerant within the system to evaporate and condense twice in one refrigeration
cycle, thereby increasing the compressor capacity over typical systems without adding
any additional power to the compressor. This, in turn, increases the overall efficiency
of the system by providing more dehumidification per kilowatt of power used. The lower
humidity of the output airflow may allow for increased drying potential, which may
be beneficial in certain applications (e.g., fire and flood restoration).
[0007] Certain embodiments of the present disclosure may include some, all, or none of the
above advantages. One or more other technical advantages may be readily apparent to
those skilled in the art from the figures, descriptions, and claims included herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] To provide a more complete understanding of the present invention and the features
and advantages thereof, reference is made to the following description taken in conjunction
with the accompanying drawings, in which:
FIGURE 1 illustrates an example split system for reducing the humidity of air within
a structure, according to certain embodiments;
FIGURE 2 illustrates an example portable system for reducing the humidity of air within
a structure, according to certain embodiments;
FIGURES 3 and 4 illustrate an example dehumidification system that may be used by
the systems of FIGURES 1 and 2 to reduce the humidity of air within a structure, according
to certain embodiments;
FIGURE 5 illustrates an example dehumidification method that may be used by the systems
of FIGURES 1 and 2 to reduce the humidity of air within a structure, according to
certain embodiments;
FIGURE 6 illustrates an example dehumidification system, according to certain embodiments;
FIGURE 7 illustrates an example condenser system for use in the system described herein,
according to certain embodiments;
FIGURE 8 illustrates an example dehumidification system, according to certain embodiments;
FIGURES 9 and 10 illustrate examples of single coil packs for use in the system described
herein, according to certain embodiments; and
FIGURES 11, 12, 13, and 14 illustrate an example of a primary evaporator comprising
three circuits for use in the system described herein, according to certain 25 embodiments.
DETAILED DESCRIPTION OF THE DRAWINGS
[0009] In certain situations, it is desirable to reduce the humidity of air within a structure.
For example, in fire and flood restoration applications, it may be desirable to remove
water from a damaged structure by placing one or more portable dehumidifiers unit
within the structure. As another example, in areas that experience weather with high
humidity levels, or in buildings where low humidity levels are required (e.g., libraries),
it may be desirable to install a dehumidification unit within a central air conditioning
system. Furthermore, it may be necessary to hold a desired humidity level in some
commercial applications. Current dehumidifiers, however, have proven inadequate or
inefficient in various respects.
[0010] To address the inefficiencies and other issues with current dehumidification systems,
the disclosed embodiments provide a dehumidification system that includes a secondary
evaporator and a secondary condenser, which causes part of the refrigerant within
the multi-stage system to evaporate and condense twice in one refrigeration cycle.
This increases the compressor capacity over typical systems without adding any additional
power to the compressor. This, in turn, increases the overall efficiency of the system
by providing more dehumidification per kilowatt of power used.
[0011] FIGURE 1 illustrates an example dehumidification system 100 for supplying dehumidified
air 106 to a structure 102, according to certain embodiments. Dehumidification system
100 includes an evaporator system 104 located within structure 102. Structure 102
may include all or a portion of a building or other suitable enclosed space, such
as an apartment building, a hotel, an office space, a commercial building, or a private
dwelling (e.g., a house). Evaporator system 104 receives inlet air 101 from within
structure 102, reduces the moisture in received inlet air 101, and supplies dehumidified
air 106 back to structure 102. Evaporator system 104 may distribute dehumidified air
106 throughout structure 102 via air ducts, as illustrated.
[0012] In general, dehumidification system 100 is a split system wherein evaporator system
104 is coupled to a remote condenser system 108 that is located external to structure
102. Remote condenser system 108 may include a condenser unit 112 and a compressor
unit 114 that facilitate the functions of evaporator system 104 by processing a flow
of refrigerant as part of a refrigeration cycle. The flow of refrigerant may include
any suitable cooling material, such as R410a refrigerant. In certain embodiments,
compressor unit 114 may receive the flow of refrigerant vapor from evaporator system
104 via a refrigerant line 116. Compressor unit 114 may pressurize the flow of refrigerant,
thereby increasing the temperature of the refrigerant. The speed of the compressor
may be modulated to effectuate desired operating characteristics. Condenser unit 112
may receive the pressurized flow of refrigerant vapor from compressor unit 114 and
cool the pressurized refrigerant by facilitating heat transfer from the flow of refrigerant
to the ambient air exterior to structure 102. In certain embodiments, remote condenser
system 108 may utilize a heat exchanger, such as a microchannel heat exchanger to
remove heat from the flow of refrigerant. Remote condenser system 108 may include
a fan that draws ambient air from outside structure 102 for use in cooling the flow
of refrigerant. In certain embodiments, the speed of this fan is modulated to effectuate
desired operating characteristics. An illustrative embodiment of an example condenser
system is shown, for example, in FIGURE 7 (described in further detail below).
[0013] After being cooled and condensed to liquid by condenser unit 112, the flow of refrigerant
may travel by a refrigerant line 118 to evaporator system 104. In certain embodiments,
the flow of refrigerant may be received by an expansion device (described in further
detail below) that reduces the pressure of the flow of refrigerant, thereby reducing
the temperature of the flow of refrigerant. An evaporator unit (described in further
detail below) of evaporator system 104 may receive the flow of refrigerant from the
expansion device and use the flow of refrigerant to dehumidify and cool an incoming
airflow. The flow of refrigerant may then flow back to remote condenser system 108
and repeat this cycle.
[0014] In certain embodiments, evaporator system 104 may be installed in series with an
air mover. An air mover may include a fan that blows air from one location to another.
An air mover may facilitate distribution of outgoing air from evaporator system 104
to various parts of structure 102. An air mover and evaporator system 104 may have
separate return inlets from which air is drawn. In certain embodiments, outgoing air
from evaporator system 104 may be mixed with air produced by another component (e.g.,
an air conditioner) and blown through air ducts by the air mover. In other embodiments,
evaporator system 104 may perform both cooling and dehumidifying and thus may be used
without a conventional air conditioner.
[0015] Although a particular implementation of dehumidification system 100 is illustrated
and primarily described, the present disclosure contemplates any suitable implementation
of dehumidification system 100, according to particular needs. Moreover, although
various components of dehumidification system 100 have been depicted as being located
at particular positions, the present disclosure contemplates those components being
positioned at any suitable location, according to particular needs.
[0016] FIGURE 2 illustrates an example portable dehumidification system 200 for reducing
the humidity of air within structure 102, according to certain embodiments of the
present disclosure. Dehumidification system 200 may be positioned anywhere within
structure 102 in order to direct dehumidified air 106 towards areas that require dehumidification
(e.g., water-damaged areas). In general, dehumidification system 200 receives inlet
airflow 101, removes water from the inlet airflow 101, and discharges dehumidified
air 106 air back into structure 102. In certain embodiments, structure 102 includes
a space that has suffered water damage (e.g., as a result of a flood or fire). In
order to restore the water-damaged structure 102, one or more dehumidification systems
200 may be strategically positioned within structure 102 in order to quickly reduce
the humidity of the air within the structure 102 and thereby dry the portions of structure
102 that suffered water damage.
[0017] Although a particular implementation of portable dehumidification system 200 is illustrated
and primarily described, the present disclosure contemplates any suitable implementation
of portable dehumidification system 200, according to particular needs. Moreover,
although various components of portable dehumidification system 200 have been depicted
as being located at particular positions within structure 102, the present disclosure
contemplates those components being positioned at any suitable location, according
to particular needs.
[0018] FIGURES 3 and 4 illustrate an example dehumidification system 300 that may be used
by dehumidification system 100 and portable dehumidification system 200 of FIGURES
1 and 2 to reduce the humidity of air within structure 102. Dehumidification system
300 includes a primary evaporator 310, a primary condenser 330, a secondary evaporator
340, a secondary condenser 320, a compressor 360, a primary metering device 380, a
secondary metering device 390, and a fan 370. In some embodiments, dehumidification
system 300 may additionally include a sub-cooling coil 350. In certain embodiments,
sub-cooling coil 350 and primary condenser 330 are combined into a single coil. A
flow of refrigerant 305 is circulated through dehumidification system 300 as illustrated.
In general, dehumidification system 300 receives inlet airflow 101, removes water
from inlet airflow 101, and discharges dehumidified air 106. Water is removed from
inlet air 101 using a refrigeration cycle of flow of refrigerant 305. By including
secondary evaporator 340 and secondary condenser 320, however, dehumidification system
300 causes at least part of the flow of refrigerant 305 to evaporate and condense
twice in a single refrigeration cycle. This increases the refrigeration capacity over
typical systems without adding any additional power to the compressor, thereby increasing
the overall dehumidification efficiency of the system.
[0019] In general, dehumidification system 300 attempts to match the saturating temperature
of secondary evaporator 340 to the saturating temperature of secondary condenser 320.
The saturating temperature of secondary evaporator 340 and secondary condenser 320
generally is controlled according to the equation: (temperature of inlet air 101 +
temperature of second airflow 315) / 2. As the saturating temperature of secondary
evaporator 340 is lower than inlet air 101, evaporation happens in secondary evaporator
340. As the saturating temperature of secondary condenser 320 is higher than second
airflow 315, condensation happens in the secondary condenser 320. The amount of refrigerant
305 evaporating in secondary evaporator 340 is substantially equal to that condensing
in secondary condenser 320.
[0020] Primary evaporator 310 receives flow of refrigerant 305 from secondary metering device
390 and outputs flow of refrigerant 305 to compressor 360. Primary evaporator 310
may be any type of coil (e.g., fin tube, micro channel, etc.). Primary evaporator
310 receives first airflow 345 from secondary evaporator 340 and outputs second airflow
315 to secondary condenser 320. Second airflow 315, in general, is at a cooler temperature
than first airflow 345. To cool incoming first airflow 345, primary evaporator 310
transfers heat from first airflow 345 to flow of refrigerant 305, thereby causing
flow of refrigerant 305 to evaporate at least partially from liquid to gas. This transfer
of heat from first airflow 345 to flow of refrigerant 305 also removes water from
first airflow 345.
[0021] Secondary condenser 320 receives flow of refrigerant 305 from secondary evaporator
340 and outputs flow of refrigerant 305 to secondary metering device 390. Secondary
condenser 320 may be any type of coil (e.g., fin tube, micro channel, etc.). Secondary
condenser 320 receives second airflow 315 from primary evaporator 310 and outputs
third airflow 325. Third airflow 325 is, in general, warmer and drier (i.e., the dew
point will be the same but relative humidity will be lower) than second airflow 315.
Secondary condenser 320 generates third airflow 325 by transferring heat from flow
of refrigerant 305 to second airflow 315, thereby causing flow of refrigerant 305
to condense at least partially from gas to liquid.
[0022] Primary condenser 330 receives flow of refrigerant 305 from compressor 360 and outputs
flow of refrigerant 305 to either primary metering device 380 or sub-cooling coil
350. Primary condenser 330 may be any type of coil (e.g., fin tube, micro channel,
etc.). Primary condenser 330 receives either third airflow 325 or fourth airflow 355
and outputs dehumidified air 106. Dehumidified air 106 is, in general, warmer and
drier (i.e., have a lower relative humidity) than third airflow 325 and fourth airflow
355. Primary condenser 330 generates dehumidified air 106 by transferring heat from
flow of refrigerant 305, thereby causing flow of refrigerant 305 to condense at least
partially from gas to liquid. In some embodiments, primary condenser 330 completely
condenses flow of refrigerant 305 to a liquid (i.e., 100% liquid). In other embodiments,
primary condenser 330 partially condenses flow of refrigerant 305 to a liquid (i.e.,
less than 100% liquid). In certain embodiments, as shown in FIGURE 4, a portion of
primary condenser 330 receives a separate airflow in addition to airflow 101. For
example, the right-most edge of primary condenser 330 of FIGURE 4 extends beyond,
or overhangs, the right-most edges of secondary evaporator 340, primary evaporator
310, secondary condenser 320, and sub-cooling coil 350. This overhanging portion of
primary condenser 330 may receive an additional separate airflow.
[0023] Secondary evaporator 340 receives flow of refrigerant 305 from primary metering device
380 and outputs flow of refrigerant 305 to secondary condenser 320. Secondary evaporator
340 may be any type of coil (e.g., fin tube, micro channel, etc.). Secondary evaporator
340 receives inlet air 101 and outputs first airflow 345 to primary evaporator 310.
First airflow 345, in general, is at a cooler temperature than inlet air 101. To cool
incoming inlet air 101, secondary evaporator 340 transfers heat from inlet air 101
to flow of refrigerant 305, thereby causing flow of refrigerant 305 to evaporate at
least partially from liquid to gas.
[0024] Sub-cooling coil 350, which is an optional component of dehumidification system 300,
sub-cools the liquid refrigerant 305 as it leaves primary condenser 330. This, in
turn, supplies primary metering device 380 with a liquid refrigerant that is up to
30 degrees (or more) cooler than before it enters sub-cooling coil 350. For example,
if flow of refrigerant 305 entering sub-cooling coil 350 is 340psig/105°F/60% vapor,
flow of refrigerant 305 may be 340psig/80°F/0% vapor as it leaves sub-cooling coil
350. The sub-cooled refrigerant 305 has a greater heat enthalpy factor as well as
a greater density, which results in reduced cycle times and frequency of the evaporation
cycle of flow of refrigerant 305. This results in greater efficiency and less energy
use of dehumidification system 300. Embodiments of dehumidification system 300 may
or may not include a sub-cooling coil 350. For example, embodiments of dehumidification
system 300 utilized within portable dehumidification system 200 that have a micro-channel
condenser 330 or 320 may include a sub-cooling coil 350, while embodiments of dehumidification
system 300 that utilize another type of condenser 330 or 320 may not include a sub-cooling
coil 350. As another example, dehumidification system 300 utilized within a split
system such as dehumidification system 100 may not include a sub-cooling coil 350.
[0025] Compressor 360 pressurizes flow of refrigerant 305, thereby increasing the temperature
of refrigerant 305. For example, if flow of refrigerant 305 entering compressor 360
is 128psig/52°F/100% vapor, flow of refrigerant 305 may be 340psig/150°F/100% vapor
as it leaves compressor 360. Compressor 360 receives flow of refrigerant 305 from
primary evaporator 310 and supplies the pressurized flow of refrigerant 305 to primary
condenser 330.
[0026] Fan 370 may include any suitable components operable to draw inlet air 101 into dehumidification
system 300 and through secondary evaporator 340, primary evaporator 310, secondary
condenser 320, sub-cooling coil 350 and primary condenser 330. Fan 370 may be any
type of air mover (e.g. axial fan, forward inclined impeller, and backward inclined
impeller, etc.). For example, fan 370 may be a backward inclined impeller positioned
adjacent to primary condenser 330 as illustrated in FIGURE 3. While fan 370 is depicted
in FIGURE 3 as being located adjacent to primary condenser 330, it should be understood
that fan 370 may be located anywhere along the airflow path of dehumidification system
300. For example, fan 370 may be positioned in the airflow path of any one of airflows
101, 345, 315, 325, 355, or 106. Moreover, dehumidification system 300 may include
one or more additional fans positioned within any one or more of these airflow paths.
[0027] Primary metering device 380 and secondary metering device 390 are any appropriate
type of metering/expansion device. In some embodiments, primary metering device 380
is a thermostatic expansion valve (TXV) and secondary metering device 390 is a fixed
orifice device (or vice versa). In certain embodiments, metering devices 380 and 390
remove pressure from flow of refrigerant 305 to allow expansion or change of state
from a liquid to a vapor in evaporators 310 and 340. The high- pressure liquid (or
mostly liquid) refrigerant entering metering devices 380 and 390 is at a higher temperature
than the liquid refrigerant 305 leaving metering devices 380 and 390. For example,
if flow of refrigerant 305 entering primary metering device 380 is 340psig/80°F/0%
vapor, flow of refrigerant 305 may be 196psig/68°F/5% vapor as it leaves primary metering
device 380. As another example, if flow of refrigerant 305 entering secondary metering
device 390 is 196psig/68°F/4% vapor, flow of refrigerant 305 may be 128psig/44°F/14%
vapor as it leaves secondary metering device 390.
[0028] Refrigerant 305 may be any suitable refrigerant such as R410a. In general, dehumidification
system 300 utilizes a closed refrigeration loop of refrigerant 305 that passes from
compressor 360 through primary condenser 330, (optionally) sub-cooling coil 350, primary
metering device 380, secondary evaporator 340, secondary condenser 320, secondary
metering device 390, and primary evaporator 310. Compressor 360 pressurizes flow of
refrigerant 305, thereby increasing the temperature of refrigerant 305. Primary and
secondary condensers 330 and 320, which may include any suitable heat exchangers,
cool the pressurized flow of refrigerant 305 by facilitating heat transfer from the
flow of refrigerant 305 to the respective airflows passing through them (i.e., fourth
airflow 355 and second airflow 315). The cooled flow of refrigerant 305 leaving primary
and secondary condensers 330 and 320 may enter a respective expansion device (i.e.,
primary metering device 380 and secondary metering device 390) that is operable to
reduce the pressure of flow of refrigerant 305, thereby reducing the temperature of
flow of refrigerant 305. Primary and secondary evaporators 310 and 340, which may
include any suitable heat exchanger, receive flow of refrigerant 305 from secondary
metering device 390 and primary metering device 380, respectively. Primary and secondary
evaporators 310 and 340 facilitate the transfer of heat from the respective airflows
passing through them (i.e., inlet air 101 and first airflow 345) to flow of refrigerant
305. Flow of refrigerant 305, after leaving primary evaporator 310, passes back to
compressor 360, and the cycle is repeated.
[0029] In certain embodiments, the above-described refrigeration loop may be configured
such that evaporators 310 and 340 operate in a flooded state. In other words, flow
of refrigerant 305 may enter evaporators 310 and 340 in a liquid state, and a portion
of flow of refrigerant 305 may still be in a liquid state as it exits evaporators
310 and 340. Accordingly, the phase change of flow of refrigerant 305 (liquid to vapor
as heat is transferred to flow of refrigerant 305) occurs across evaporators 310 and
340, resulting in nearly constant pressure and temperature across the entire evaporators
310 and 340 (and, as a result, increased cooling capacity).
[0030] In operation of example embodiments of dehumidification system 300, inlet air 101
may be drawn into dehumidification system 300 by fan 370. Inlet air 101 passes though
secondary evaporator 340 in which heat is transferred from inlet air 101 to the cool
flow of refrigerant 305 passing through secondary evaporator 340. As a result, inlet
air 101 may be cooled. As an example, if inlet air 101 is 80° F/60% humidity, secondary
evaporator 340 may output first airflow 345 at 70° F/84% humidity. This may cause
flow of refrigerant 305 to partially vaporize within secondary evaporator 340. For
example, if flow of refrigerant 305 entering secondary evaporator 340 is 196psig/68°F/5%
vapor, flow of refrigerant 305 may be 196psig/68°F/38% vapor as it leaves secondary
evaporator 340.
[0031] The cooled inlet air 101 leaves secondary evaporator 340 as first airflow 345 and
enters primary evaporator 310. Like secondary evaporator 340, primary evaporator 310
transfers heat from first airflow 345 to the cool flow of refrigerant 305 passing
through primary evaporator 310. As a result, first airflow 345 may be cooled to or
below its dew point temperature, causing moisture in first airflow 345 to condense
(thereby reducing the absolute humidity of first airflow 345). As an example, if first
airflow 345 is 70° F/84% humidity, primary evaporator 310 may output second airflow
315 at 54° F/98% humidity. This may cause flow of refrigerant 305 to partially or
completely vaporize within primary evaporator 310. For example, if flow of refrigerant
305 entering primary evaporator 310 is 128psig/44°F/14% vapor, flow of refrigerant
305 may be 128psig/52°F/100% vapor as it leaves primary evaporator 310. In certain
embodiments, the liquid condensate from first airflow 345 may be collected in a drain
pan connected to a condensate reservoir, as illustrated in FIGURE 4. Additionally,
the condensate reservoir may include a condensate pump that moves collected condensate,
either continually or at periodic intervals, out of dehumidification system 300 (e.g.,
via a drain hose) to a suitable drainage or storage location.
[0032] The cooled first airflow 345 leaves primary evaporator 310 as second airflow 315
and enters secondary condenser 320. Secondary condenser 320 facilitates heat transfer
from the hot flow of refrigerant 305 passing through the secondary condenser 320 to
second airflow 315. This reheats second airflow 315, thereby decreasing the relative
humidity of second airflow 315. As an example, if second airflow 315 is 54°F/98% humidity,
secondary condenser 320 may output third airflow 325 at 65° F/68% humidity. This may
cause flow of refrigerant 305 to partially or completely condense within secondary
condenser 320. For example, if flow of refrigerant 305 entering secondary condenser
320 is 196psig/68°F/38% vapor, flow of refrigerant 305 may be 196psig/68°F/4% vapor
as it leaves secondary condenser 320.
[0033] In some embodiments, the dehumidified second airflow 315 leaves secondary condenser
320 as third airflow 325 and enters primary condenser 330. Primary condenser 330 facilitates
heat transfer from the hot flow of refrigerant 305 passing through the primary condenser
330 to third airflow 325. This further heats third airflow 325, thereby further decreasing
the relative humidity of third airflow 325. As an example, if third airflow 325 is
65° F/68% humidity, secondary condenser 320 may output dehumidified air 106 at 102°
F/19% humidity. This may cause flow of refrigerant 305 to partially or completely
condense within primary condenser 330. For example, if flow of refrigerant 305 entering
primary condenser 330 is 340psig/150°F/100% vapor, flow of refrigerant 305 may be
340psig/105°F/60% vapor as it leaves primary condenser 330.
[0034] As described above, some embodiments of dehumidification system 300 may include a
sub-cooling coil 350 in the airflow between secondary condenser 320 and primary condenser
330. Sub-cooling coil 350 facilitates heat transfer from the hot flow of refrigerant
305 passing through sub-cooling coil 350 to third airflow 325. This further heats
third airflow 325, thereby further decreasing the relative humidity of third airflow
325. As an example, if third airflow 325 is 65° F/68% humidity, sub-cooling coil 350
may output fourth airflow 355 at 81° F/37% humidity. This may cause flow of refrigerant
305 to partially or completely condense within sub-cooling coil 350. For example,
if flow of refrigerant 305 entering sub-cooling coil 350 is 340psig/150°F/60% vapor,
flow of refrigerant 305 may be 340psig/80°F/0% vapor as it leaves sub-cooling coil
350.
[0035] Some embodiments of dehumidification system 300 may include a controller that may
include one or more computer systems at one or more locations. Each computer system
may include any appropriate input devices (such as a keypad, touch screen, mouse,
or other device that can accept information), output devices, mass storage media,
or other suitable components for receiving, processing, storing, and communicating
data. Both the input devices and output devices may include fixed or removable storage
media such as a magnetic computer disk, CD-ROM, or other suitable media to both receive
input from and provide output to a user. Each computer system may include a personal
computer, workstation, network computer, kiosk, wireless data port, personal data
assistant (PDA), one or more processors within these or other devices, or any other
suitable processing device. In short, the controller may include any suitable combination
of software, firmware, and hardware.
[0036] The controller may additionally include one or more processing modules. Each processing
module may each include one or more microprocessors, controllers, or any other suitable
computing devices or resources and may work, either alone or with other components
of dehumidification system 300, to provide a portion or all of the functionality described
herein. The controller may additionally include (or be communicatively coupled to
via wireless or wireline communication) computer memory. The memory may include any
memory or database module and may take the form of volatile or non-volatile memory,
including, without limitation, magnetic media, optical media, random access memory
(RAM), read-only memory (ROM), removable media, or any other suitable local or remote
memory component.
[0037] Although particular implementations of dehumidification system 300 are illustrated
and primarily described, the present disclosure contemplates any suitable implementation
of dehumidification system 300, according to particular needs. Moreover, although
various components of dehumidification system 300 have been depicted as being located
at particular positions and relative to one another, the present disclosure contemplates
those components being positioned at any suitable location, according to particular
needs.
[0038] FIGURE 5 illustrates an example dehumidification method 500 that may be used by dehumidification
system 100 and portable dehumidification system 200 of FIGURES 1 and 2 to reduce the
humidity of air within structure 102. Method 500 may begin in step 510 where a secondary
evaporator receives an inlet airflow and outputs a first airflow. In some embodiments,
the secondary evaporator is secondary evaporator 340. In some embodiments, the inlet
airflow is inlet air 101 and the first airflow is first airflow 345. In some embodiments,
the secondary evaporator of step 510 receives a flow of refrigerant from a primary
metering device such as primary metering device 380 and supplies the flow of refrigerant
(in a changed state) to a secondary condenser such as secondary condenser 320. In
some embodiments, the flow of refrigerant of method 500 is flow of refrigerant 305
described above.
[0039] At step 520, a primary evaporator receives the first airflow of step 510 and outputs
a second airflow. In some embodiments, the primary evaporator is primary evaporator
310 and the second airflow is second airflow 315. In some embodiments, the primary
evaporator of step 520 receives the flow of refrigerant from a secondary metering
device such as secondary metering device 390 and supplies the flow of refrigerant
(in a changed state) to a compressor such as compressor 360.
[0040] At step 530, a secondary condenser receives the second air flow of step 520 and outputs
a third airflow. In some embodiments, the secondary condenser is secondary condenser
320 and the third airflow is third airflow 325. In some embodiments, the secondary
condenser of step 530 receives a flow of refrigerant from the secondary evaporator
of step 510 and supplies the flow of refrigerant (in a changed state) to a secondary
metering device such as secondary metering device 390.
[0041] At step 540, a primary condenser receives the third airflow of step 530 and outputs
a dehumidified airflow. In some embodiments, the primary condenser is primary condenser
330 and the dehumidified airflow is dehumidified air 106. In some embodiments, the
primary condenser of step 540 receives a flow of refrigerant from the compressor of
step 520 and supplies the flow of refrigerant (in a changed state) to the primary
metering device of step 510. In alternate embodiments, the primary condenser of step
540 supplies the flow of refrigerant (in a changed state) to a sub-cooling coil such
as sub-cooling coil 350 which in turn supplies the flow of refrigerant (in a changed
state) to the primary metering device of step 510.
[0042] At step 550, a compressor receives the flow of refrigerant from the primary evaporator
of step 520 and provides the flow of refrigerant (in a changed state) to the primary
condenser of step 540. After step 550, method 500 may end.
[0043] Particular embodiments may repeat one or more steps of method 500 of FIGURE 5, where
appropriate. Although this disclosure describes and illustrates particular steps of
the method of FIGURE 5 as occurring in a particular order, this disclosure contemplates
any suitable steps of the method of FIGURE 5 occurring in any suitable order. Moreover,
although this disclosure describes and illustrates an example dehumidification method
for reducing the humidity of air within a structure including the particular steps
of the method of FIGURE 5, this disclosure contemplates any suitable method for reducing
the humidity of air within a structure including any suitable steps, which may include
all, some, or none of the steps of the method of FIGURE 5, where appropriate. Furthermore,
although this disclosure describes and illustrates particular components, devices,
or systems carrying out particular steps of the method of FIGURE 5, this disclosure
contemplates any suitable combination of any suitable components, devices, or systems
carrying out any suitable steps of the method of FIGURE 5.
[0044] While the example method of FIGURE 5 is described at times above with respect to
dehumidification system 300 of FIGURE 3, it should be understood that the same or
similar methods can be carried out using any of the dehumidification systems described
herein, including dehumidification systems 600 and 800 of FIGURES 6 and 8 (described
below). Moreover, it should be understood that, with respect to the example method
of FIGURE 500, reference to an evaporator or condenser can refer to an evaporator
portion or condenser portion of a single coil pack operable to perform the functions
of these components, for example, as described above with respect to examples of FIGURES
9 and 10.
[0045] FIGURE 6 illustrates an example dehumidification system 600 that may be used in accordance
with split dehumidification system 100 of FIGURE 1 to reduce the humidity of air within
structure 102. Dehumidification system 600 includes a dehumidification unit 602, which
is generally indoors, and a condenser system 604 (e.g., condenser system 108 of FIGURE
1). Dehumidification unit 602 includes a primary evaporator 610, a secondary evaporator
640, a secondary condenser 620, a primary metering device 680, a secondary metering
device 690, and a first fan 670, while condenser system 604 includes a primary condenser
630, a compressor 660, an optional sub-cooling coil 650 and a second fan 695.
[0046] A flow of refrigerant 605 is circulated through dehumidification system 600 as illustrated.
In general, dehumidification unit 602 receives inlet airflow 601, removes water from
inlet airflow 601, and discharges dehumidified air 625 into a conditioned space. Water
is removed from inlet air 601 using a refrigeration cycle of flow of refrigerant 605.
The flow of refrigerant 605 through system 600 of FIGURE 6 proceeds in a similar manner
to that of the flow of refrigerant 305 through dehumidification system 300 of FIGURE
3. However, the path of airflow through system 600 is different than that through
system 300, as described herein. By including secondary evaporator 640 and secondary
condenser 620, however, dehumidification system 600 causes at least part of the flow
of refrigerant 605 to evaporate and condense twice in a single refrigeration cycle.
This increases refrigerating capacity over typical systems without requiring any additional
power to the compressor, thereby increasing the overall efficiency of the system.
[0047] The split configuration of system 600, which includes dehumidification unit 602 and
condenser system 604, allows heat from the cooling and dehumidification process to
be rejected outdoors or to an unconditioned space (e.g., external to a space being
dehumidified). This allows dehumidification system 600 to have a similar footprint
to that of typical central air conditioning systems or heat pumps. In general, the
temperature of third airflow 625 output to the conditioned space from system 600 is
significantly decreased compared to that of airflow 106 output from system 300 of
FIGURE 3. Thus, the configuration of system 600 allows dehumidified air to be provided
to the conditioned space at a decreased temperature. Accordingly, system 600 may perform
functions of both a dehumidifier (dehumidifying air) and a central air conditioner
(cooling air).
[0048] In general, dehumidification system 600 attempts to match the saturating temperature
of secondary evaporator 640 to the saturating temperature of secondary condenser 620.
The saturating temperature of secondary evaporator 640 and secondary condenser 620
generally is controlled according to the equation: (temperature of inlet air 601 +
temperature of second airflow 615) / 2. As the saturating temperature of secondary
evaporator 640 is lower than inlet air 601, evaporation happens in secondary evaporator
640. As the saturating temperature of secondary condenser 620 is higher than second
airflow 615, condensation happens in secondary condenser 620. The amount of refrigerant
605 evaporating in secondary evaporator 640 is substantially equal to that condensing
in secondary condenser 620.
[0049] Primary evaporator 610 receives flow of refrigerant 605 from secondary metering device
690 and outputs flow of refrigerant 605 to compressor 660. Primary evaporator 610
may be any type of coil (e.g., fin tube, micro channel, etc.). Primary evaporator
610 receives first airflow 645 from secondary evaporator 640 and outputs second airflow
615 to secondary condenser 620. Second airflow 615, in general, is at a cooler temperature
than first airflow 645. To cool incoming first airflow 645, primary evaporator 610
transfers heat from first airflow 645 to flow of refrigerant 605, thereby causing
flow of refrigerant 605 to evaporate at least partially from liquid to gas. This transfer
of heat from first airflow 645 to flow of refrigerant 605 also removes water from
first airflow 645.
[0050] Secondary condenser 620 receives flow of refrigerant 605 from secondary evaporator
640 and outputs flow of refrigerant 605 to secondary metering device 690. Secondary
condenser 620 may be any type of coil (e.g., fin tube, micro channel, etc.). Secondary
condenser 620 receives second airflow 615 from primary evaporator 610 and outputs
third airflow 625. Third airflow 625 is, in general, warmer and drier (i.e., the dew
point will be the same but relative humidity will be lower) than second airflow 615.
Secondary condenser 620 generates third airflow 625 by transferring heat from flow
of refrigerant 605 to second airflow 615, thereby causing flow of refrigerant 605
to condense at least partially from gas to liquid. As described above, third airflow
625 is output into the conditioned space. In other embodiments (e.g., as shown in
FIGURE 8), third airflow 625 may first pass through and/or over sub-cooling coil 650
before being output into the conditioned space at a further decreased relative humidity.
[0051] Refrigerant 605 flows outdoors or to an unconditioned space to compressor 660 of
condenser system 604. Compressor 660 pressurizes flow of refrigerant 605, thereby
increasing the temperature of refrigerant 605. For example, if flow of refrigerant
605 entering compressor 660 is 128psig/52°F/100% vapor, flow of refrigerant 605 may
be 340psig/150°F/100% vapor as it leaves compressor 660. Compressor 660 receives flow
of refrigerant 605 from primary evaporator 610 and supplies the pressurized flow of
refrigerant 605 to primary condenser 630.
[0052] Primary condenser 630 receives flow of refrigerant 605 from compressor 660 and outputs
flow of refrigerant 605 to sub-cooling coil 650. Primary condenser 630 may be any
type of coil (e.g., fin tube, micro channel, etc.). Primary condenser 630 and sub-cooling
coil 650 receive first outdoor airflow 606 and output second outdoor airflow 608.
Second outdoor airflow 608 is, in general, warmer (i.e., have a lower relative humidity)
than first outdoor airflow 606. Primary condenser 630 transfers heat from flow of
refrigerant 605, thereby causing flow of refrigerant 605 to condense at least partially
from gas to liquid. In some embodiments, primary condenser 630 completely condenses
flow of refrigerant 605 to a liquid (i.e., 100% liquid). In other embodiments, primary
condenser 630 partially condenses flow of refrigerant 605 to a liquid (i.e., less
than 100% liquid).
[0053] Sub-cooling coil 650, which is an optional component of dehumidification system 600,
sub-cools the liquid refrigerant 605 as it leaves primary condenser 630. This, in
turn, supplies primary metering device 680 with a liquid refrigerant that is 30 degrees
(or more) cooler than before it enters sub-cooling coil 650. For example, if flow
of refrigerant 605 entering sub-cooling coil 650 is 340psig/105°F/60% vapor, flow
of refrigerant 605 may be 340psig/80°F/0% vapor as it leaves sub-cooling coil 650.
The sub-cooled refrigerant 605 has a greater heat enthalpy factor as well as a greater
density, which improves energy transfer between airflow and evaporator resulting in
the removal of further latent heat from refrigerant 605. This further results in greater
efficiency and less energy use of dehumidification system 600. Embodiments of dehumidification
system 600 may or may not include a sub-cooling coil 650.
[0054] In certain embodiments, sub-cooling coil 650 and primary condenser 630 are combined
into a single coil. Such a single coil includes appropriate circuiting for flow of
airflows 606 and 608 and refrigerant 605. An illustrative example of a condenser system
604 comprising a single coil condenser and sub-cooling coil is shown in FIGURE 7.
The single unit coil comprises interior tubes 710 corresponding to the condenser and
exterior tubes 705 corresponding to the sub-cooling coil. Refrigerant may be directed
through the interior tubes 710 before flowing through exterior tubes 705. In the illustrative
example shown in FIGURE 7, airflow is drawn through the single unit coil by fan 695
and expelled upwards. It should be understood, however, that condenser systems of
other embodiments can include a condenser, compressor, optional sub-cooling coil,
and fan with other configurations known in the art.
[0055] Secondary evaporator 640 receives flow of refrigerant 605 from primary metering device
680 and outputs flow of refrigerant 605 to secondary condenser 620. Secondary evaporator
640 may be any type of coil (e.g., fin tube, micro channel, etc.). Secondary evaporator
640 receives inlet air 601 and outputs first airflow 645 to primary evaporator 610.
First airflow 645, in general, is at a cooler temperature than inlet air 601. To cool
incoming inlet air 601, secondary evaporator 640 transfers heat from inlet air 601
to flow of refrigerant 605, thereby causing flow of refrigerant 605 to evaporate at
least partially from liquid to gas.
[0056] Fan 670 may include any suitable components operable to draw inlet air 601 into dehumidification
unit 602 and through secondary evaporator 640, primary evaporator 610, and secondary
condenser 620. Fan 670 may be any type of air mover e.g., axial fan, forward inclined
impeller, and backward inclined impeller, etc.). For example, fan 670 may be a backward
inclined impeller positioned adjacent to secondary condenser 620.
[0057] While fan 670 is depicted in FIGURE 6 as being located adjacent to condenser 620,
it should be understood that fan 670 may be located anywhere along the airflow path
of dehumidification unit 602. For example, fan 670 may be positioned in the airflow
path of any one of airflows 601, 645, 615, or 625. Moreover, dehumidification unit
602 may include one or more additional fans positioned within any one or more of these
airflow paths. Similarly, while fan 695 of condenser system 604 is depicted in FIGURE
6 as being located above primary condenser 630, it should be understood that fan 695
may be located anywhere (e.g., above, below, beside) with respect to condenser 630
and sub-cooling coil 650, so long fan 695 is appropriately positioned and configured
to facilitate flow of airflow 606 towards primary condenser 630 and sub-cooling coil
650.
[0058] The rate of airflow generated by fan 670 may be different than that generated by
fan 695. For example, the flow rate of airflow 606 generated by fan 695 may be higher
than the flow rate of airflow 601 generated by fan 670. This difference in flow rates
may provide several advantages for the dehumidification systems described herein.
For example, a large airflow generated by fan 695 may provide for improved heat transfer
at the sub-cooling coil 650 and primary condenser 630 of the condenser system 604.
In general, the rate of airflow generated by second fan 695 is between about 2-times
to 5-times that of the rate of airflow generated by first fan 670. For example, the
rate of airflow generated by first fan 670 may be from about 200 to 400 cubic feet
per minute (cfm). For example, the rate of airflow generated by second fan 695 may
be from about 900 to 1200 cubic feet per minute (cfm).
[0059] Primary metering device 680 and secondary metering device 690 are any appropriate
type of metering/expansion device. In some embodiments, primary metering device 680
is a thermostatic expansion valve (TXV) and secondary metering device 690 is a fixed
orifice device (or vice versa). In certain embodiments, metering devices 680 and 690
remove pressure from flow of refrigerant 605 to allow expansion or change of state
from a liquid to a vapor in evaporators 610 and 640. The high-pressure liquid (or
mostly liquid) refrigerant entering metering devices 680 and 690 is at a higher temperature
than the liquid refrigerant 605 leaving metering devices 680 and 690. For example,
if flow of refrigerant 605 entering primary metering device 680 is 340psig/80°F/0%
vapor, flow of refrigerant 605 may be 196psig/68°F/5% vapor as it leaves primary metering
device 680. As another example, if flow of refrigerant 605 entering secondary metering
device 690 is 196psig/68°F/4% vapor, flow of refrigerant 605 may be 128psig/44°F/14%
vapor as it leaves secondary metering device 690.
[0060] In certain embodiments, secondary metering device 690 is operated in a substantially
open state (referred to herein as a "fully open" state) such that the pressure of
refrigerant 605 entering metering device 690 is substantially the same as the pressure
of refrigerant 605 exiting metering device 605. For example, the pressure of refrigerant
605 may be 80%, 90%, 95%, 99%, or up to 100% of the pressure of refrigerant 605 entering
metering device 690. With the secondary metering device 690 operated in a "fully open"
state, primary metering device 680 is the primary source of pressure drop in dehumidification
system 600. In this configuration, airflow 615 is not substantially heated when it
passes through secondary condenser 620, and the secondary evaporator 640, primary
evaporator 610, and secondary condenser 620 effectively act as a single evaporator.
Although, less water may be removed from airflow 601 when the secondary metering device
690 is operated in a "fully open" state, airflow 606 will be output to the conditioned
space at a lower temperature than when secondary metering device 690 is not in a "fully
open" state. This configuration corresponds to a relatively high sensible heat ratio
(SHR) operating mode such that dehumidification system 600 may produce a cool airflow
625 with properties similar to those of an airflow produced by a central air conditioner.
If the rate of airflow 601 is increased to a threshold value (e.g., by increasing
the speed of fan 670 or one or more other fans of dehumidification system 600), dehumidification
system 600 may perform sensible cooling without removing water from airflow 601.
[0061] Refrigerant 605 may be any suitable refrigerant such as R410a. In general, dehumidification
system 600 utilizes a closed refrigeration loop of refrigerant 605 that passes from
compressor 660 through primary condenser 630, (optionally) sub-cooling coil 650, primary
metering device 680, secondary evaporator 640, secondary condenser 620, secondary
metering device 690, and primary evaporator 610. Compressor 660 pressurizes flow of
refrigerant 605, thereby increasing the temperature of refrigerant 605. Primary and
secondary condensers 630 and 620, which may include any suitable heat exchangers,
cool the pressurized flow of refrigerant 605 by facilitating heat transfer from the
flow of refrigerant 605 to the respective airflows passing through them (i.e., first
outdoor airflow 606 and second airflow 615). The cooled flow of refrigerant 605 leaving
primary and secondary condensers 630 and 620 may enter a respective expansion device
(i.e., primary metering device 680 and secondary metering device 690) that is operable
to reduce the pressure of flow of refrigerant 605, thereby reducing the temperature
of flow of refrigerant 605. Primary and secondary evaporators 610 and 640, which may
include any suitable heat exchanger, receive flow of refrigerant 605 from secondary
metering device 690 and primary metering device 680, respectively. Primary and secondary
evaporators 610 and 640 facilitate the transfer of heat from the respective airflows
passing through them (i.e., inlet air 601 and first airflow 645) to flow of refrigerant
605. Flow of refrigerant 605, after leaving primary evaporator 610, passes back to
compressor 660, and the cycle is repeated.
[0062] In certain embodiments, the above-described refrigeration loop may be configured
such that evaporators 610 and 640 operate in a flooded state. In other words, flow
of refrigerant 605 may enter evaporators 610 and 640 in a liquid state, and a portion
of flow of refrigerant 605 may still be in a liquid state as it exits evaporators
610 and 640. Accordingly, the phase change of flow of refrigerant 605 (liquid to vapor
as heat is transferred to flow of refrigerant 605) occurs across evaporators 610 and
640, resulting in nearly constant pressure and temperature across the entire evaporators
610 and 640 (and, as a result, increased cooling capacity).
[0063] In operation of example embodiments of dehumidification system 600, inlet air 601
may be drawn into dehumidification system 600 by fan 670. Inlet air 601 passes though
secondary evaporator 640 in which heat is transferred from inlet air 601 to the cool
flow of refrigerant 605 passing through secondary evaporator 640. As a result, inlet
air 601 may be cooled. As an example, if inlet air 601 is 80° F/60% humidity, secondary
evaporator 640 may output first airflow 645 at 70° F/84% humidity. This may cause
flow of refrigerant 605 to partially vaporize within secondary evaporator 640. For
example, if flow of refrigerant 605 entering secondary evaporator 640 is 196psig/68°F/5%
vapor, flow of refrigerant 605 may be 196psig/68°F/38% vapor as it leaves secondary
evaporator 640.
[0064] The cooled inlet air 601 leaves secondary evaporator 640 as first airflow 645 and
enters primary evaporator 610. Like secondary evaporator 640, primary evaporator 610
transfers heat from first airflow 645 to the cool flow of refrigerant 605 passing
through primary evaporator 610. As a result, first airflow 645 may be cooled to or
below its dew point temperature, causing moisture in first airflow 645 to condense
(thereby reducing the absolute humidity of first airflow 645). As an example, if first
airflow 645 is 70° F/84% humidity, primary evaporator 610 may output second airflow
615 at 54° F/98% humidity. This may cause flow of refrigerant 605 to partially or
completely vaporize within primary evaporator 610. For example, if flow of refrigerant
605 entering primary evaporator 610 is 128psig/44°F/14% vapor, flow of refrigerant
605 may be 128psig/52°F/100% vapor as it leaves primary evaporator 610. In certain
embodiments, the liquid condensate from first airflow 645 may be collected in a drain
pan connected to a condensate reservoir, as illustrated in FIGURE 4. Additionally,
the condensate reservoir may include a condensate pump that moves collected condensate,
either continually or at periodic intervals, out of dehumidification system 600 (e.g.,
via a drain hose) to a suitable drainage or storage location.
[0065] The cooled first airflow 645 leaves primary evaporator 610 as second airflow 615
and enters secondary condenser 620. Secondary condenser 620 facilitates heat transfer
from the hot flow of refrigerant 605 passing through the secondary condenser 620 to
second airflow 615. This reheats second airflow 615, thereby decreasing the relative
humidity of second airflow 615. As an example, if second airflow 615 is 54° F/98%
humidity, secondary condenser 620 may output dehumidified airflow 625 at 65° F/68%
humidity. This may cause flow of refrigerant 605 to partially or completely condense
within secondary condenser 620. For example, if flow of refrigerant 605 entering secondary
condenser 620 is 196psig/68°F/38% vapor, flow of refrigerant 605 may be 196psig/68°F/4%
vapor as it leaves secondary condenser 620. In some embodiments, second airflow 615
leaves secondary condenser 620 as dehumidified airflow 625 and is output to a conditioned
space.
[0066] Primary condenser 630 facilitates heat transfer from the hot flow of refrigerant
605 passing through the primary condenser 630 to a first outdoor airflow 606. This
heats outdoor airflow 606, which is output to the unconditioned space (e.g., outdoors)
as second outdoor airflow 608. As an example, if first outdoor airflow 606 is 65°
F/68% humidity, primary condenser 630 may output second outdoor airflow 608 at 102°
F/19% humidity. This may cause flow of refrigerant 605 to partially or completely
condense within primary condenser 630. For example, if flow of refrigerant 605 entering
primary condenser 630 is 340psig/150°F/100% vapor, flow of refrigerant 605 may be
340psig/105°F/60% vapor as it leaves primary condenser 630. As described above, some
embodiments of dehumidification system 600 may include a sub-cooling coil 650 in the
airflow between an inlet of the condenser system 604 and primary condenser 630. Sub-cooling
coil 650 facilitates heat transfer from the hot flow of refrigerant 605 passing through
sub-cooling coil 650 to first outdoor airflow 606. This heats first outdoor airflow
606, thereby increasing the temperature of first outdoor airflow 606. As an example,
if first outdoor airflow 606 is 65° F/68% humidity, sub-cooling coil 650 may output
an airflow at 81° F/37% humidity. This may cause flow of refrigerant 605 to partially
or completely condense within sub-cooling coil 650. For example, if flow of refrigerant
605 entering sub-cooling coil 650 is 340psig/150°F/60% vapor, flow of refrigerant
605 may be 340psig/80°F/0% vapor as it leaves sub-cooling coil 650.
[0067] In the embodiment depicted in FIGURE 6, sub-cooling coil 650 is within condenser
system 604. This configuration minimizes the temperature of third airflow 625, which
is output into the conditioned space. An alternative embodiment is shown as dehumidification
system 800 of FIGURE 8 in which dehumidification unit 802 includes sub-cooling coil
650. In this embodiment, airflow 625 first passes through sub-cooling coil 650 before
being output to the conditioned space as airflow 855 via fan 670. As described herein,
fan 670 can alternatively be located anywhere along the path of airflow in dehumidification
unit 802, and one or more additional fans can be included in dehumidification unit
802.
[0068] Without wishing to be bound to any particular theory, the configuration of dehumidification
system 800 is believed to be more energy efficient under common operating conditions
than that of dehumidification system 600 of FIGURE 6. For example, if the temperature
of third airflow 625 is less than the outdoor temperature (i.e., the temperature of
airflow 606), then refrigerant 605 will be more effectively cooled, or sub-cooled,
with sub-cooling coil 650 placed in the dehumidification unit 802. Such operating
conditions may be common, for example, in locations with warm climates and/or during
summer months. In certain embodiment, indoor unit 802 also includes compressor 660,
which may, for example, be located near secondary evaporator 640, primary evaporator
610, and/or secondary condenser 620 (configuration not shown).
[0069] In operation of example embodiments of dehumidification system 800, inlet air 601
may be drawn into dehumidification system 800 by fan 670. Inlet air 601 passes though
secondary evaporator 640 in which heat is transferred from inlet air 601 to the cool
flow of refrigerant 605 passing through secondary evaporator 640. As a result, inlet
air 601 may be cooled. As an example, if inlet air 601 is 80° F/60% humidity, secondary
evaporator 640 may output first airflow 645 at 70° F/84% humidity. This may cause
flow of refrigerant 605 to partially vaporize within secondary evaporator 640. For
example, if flow of refrigerant 605 entering secondary evaporator 640 is 196psig/68°F/5%
vapor, flow of refrigerant 605 may be196psig/68°F/38% vapor as it leaves secondary
evaporator 640.
[0070] The cooled inlet air 601 leaves secondary evaporator 640 as first airflow 645 and
enters primary evaporator 610. Like secondary evaporator 640, primary evaporator 610
transfers heat from first airflow 645 to the cool flow of refrigerant 605 passing
through primary evaporator 610. As a result, first airflow 645 may be cooled to or
below its dew point temperature, causing moisture in first airflow 645 to condense
(thereby reducing the absolute humidity of first airflow 645). As an example, if first
airflow 645 is 70° F/84% humidity, primary evaporator 610 may output second airflow
615 at 54° F/98% humidity. This may cause flow of refrigerant 605 to partially or
completely vaporize within primary evaporator 610. For example, if flow of refrigerant
605 entering primary evaporator 610 is 128psig/44°F/14% vapor, flow of refrigerant
605 may be 128psig/52°F/100% vapor as it leaves primary evaporator 610. In certain
embodiments, the liquid condensate from first airflow 645 may be collected in a drain
pan connected to a condensate reservoir, as illustrated in FIGURE 4. Additionally,
the condensate reservoir may include a condensate pump that moves collected condensate,
either continually or at periodic intervals, out of dehumidification system 800 (e.g.,
via a drain hose) to a suitable drainage or storage location.
[0071] The cooled first airflow 645 leaves primary evaporator 610 as second airflow 615
and enters secondary condenser 620. Secondary condenser 620 facilitates heat transfer
from the hot flow of refrigerant 605 passing through the secondary condenser 620 to
second airflow 615. This reheats second airflow 615, thereby decreasing the relative
humidity of second airflow 615. As an example, if second airflow 615 is 54°F/98% humidity,
secondary condenser 620 may output dehumidified airflow 625 at65° F/68% humidity.
This may cause flow of refrigerant 605 to partially or completely condense within
secondary condenser 620. For example, if flow of refrigerant 605 entering secondary
condenser 620 is 196psig/68°F/38% vapor, flow of refrigerant 605 may be 196psig/68°F/4%
vapor as it leaves secondary condenser 620. In some embodiments, second airflow 615
leaves secondary condenser 620 as dehumidified airflow 625 and is output to a conditioned
space.
[0072] Dehumidified airflow 625 enters sub-cooling coil 650, which facilitates heat transfer
from the hot flow of refrigerant 605 passing through sub-cooling coil 650 to dehumidified
airflow 625. This heats dehumidified airflow 625, thereby further decreasing the humidity
of dehumidified airflow 625. As an example, if dehumidified airflow 625 is 65° F/68%
humidity, sub-cooling coil 650 may output an airflow 855 at 81° F/37% humidity. This
may cause flow of refrigerant 605 to partially or completely condense within sub-cooling
coil 650. For example, if flow of refrigerant 605 entering sub-cooling coil 650 is
340psig/150°F/60% vapor, flow of refrigerant 605 may be 340psig/80°F/0% vapor as it
leaves sub-cooling coil 650.
[0073] Primary condenser 630 facilitates heat transfer from the hot flow of refrigerant
605 passing through the primary condenser 630 to a first outdoor airflow 606. This
heats outdoor airflow 606, which is output to the unconditioned space as second outdoor
airflow 608. As an example, if first outdoor airflow 606 is 65° F/68% humidity, primary
condenser 630 may output second outdoor airflow 608 at 102° F/19% humidity. This may
cause flow of refrigerant 605 to partially or completely condense within primary condenser
630. For example, if flow of refrigerant 605 entering primary condenser 630 is 340psig/150°F/100%
vapor, flow of refrigerant 605 may be 340psig/105°F/60% vapor as it leaves primary
condenser 630.
[0074] Some embodiments of dehumidification systems 600 and 800 of FIGURES 6 and 8 may include
a controller that may include one or more computer systems at one or more locations.
Each computer system may include any appropriate input devices (such as a keypad,
touch screen, mouse, or other device that can accept information), output devices,
mass storage media, or other suitable components for receiving, processing, storing,
and communicating data. Both the input devices and output devices may include fixed
or removable storage media such as a magnetic computer disk, CD-ROM, or other suitable
media to both receive input from and provide output to a user. Each computer system
may include a personal computer, workstation, network computer, kiosk, wireless data
port, personal data assistant (PDA), one or more processors within these or other
devices, or any other suitable processing device. In short, the controller may include
any suitable combination of software, firmware, and hardware.
[0075] The controller may additionally include one or more processing modules. Each processing
module may each include one or more microprocessors, controllers, or any other suitable
computing devices or resources and may work, either alone or with other components
of dehumidification systems 600 and 800, to provide a portion or all of the functionality
described herein. The controller may additionally include (or be communicatively coupled
to via wireless or wireline communication) computer memory. The memory may include
any memory or database module and may take the form of volatile or non-volatile memory,
including, without limitation, magnetic media, optical media, random access memory
(RAM), read-only memory (ROM), removable media, or any other suitable local or remote
memory component.
[0076] Although particular implementations of dehumidification systems 600 and 800 are illustrated
and primarily described, the present disclosure contemplates any suitable implementation
of dehumidification systems 600 and 800, according to particular needs. Moreover,
although various components of dehumidification systems 600 and 800 have been depicted
as being located at particular positions and relative to one another, the present
disclosure contemplates those components being positioned at any suitable location,
according to particular needs.
[0077] In certain embodiments, the secondary evaporator (340, 640), primary evaporator (310,
610), and secondary condenser (320, 620) of FIGURES 3, 6, or 8 are combined in a single
coil pack. The single coil pack may include portions (e.g., separate refrigerant circuits)
to accommodate the respective functions of secondary evaporator, primary evaporator,
and secondary condenser, described above. An illustrative example of such a single
coil pack is shown in FIGURE 9. FIGURE 9 shows a single coil pack 900 which includes
a plurality of coils (represented by circles in FIGURE 9). Coil pack 900 includes
a secondary evaporator portion 940, primary evaporator portion 910, and secondary
condenser portion 920. The coil pack may include and/or be fluidly connectable to
metering devices 980 and 990 as shown in the exemplary case of FIGURE 9. In certain
embodiments, metering devices 980 and 990 correspond to primary metering device 380
and secondary metering device 390 of FIGURE 3.
[0078] In general, metering devices 980 and 990 may be any appropriate type of metering/expansion
device. In some embodiments, metering device 980 is a thermostatic expansion valve
(TXV) and secondary metering device 990 is a fixed orifice device (or vice versa).
In general, metering devices 980 and 990 remove pressure from flow of refrigerant
905 to allow expansion or change of state from a liquid to a vapor in evaporator portions
910 and 940. The high-pressure liquid (or mostly liquid) refrigerant 905 entering
metering devices 980 and 990 is at a higher temperature than the liquid refrigerant
905 leaving metering devices 980 and 990. For example, if flow of refrigerant 905
entering metering device 980 is 340psig/80°F/0% vapor, flow of refrigerant 905 may
be 196psig/68°F/5% vapor as it leaves primary metering device 980. As another example,
if flow of refrigerant 905 entering secondary metering device 990 is 196psig/68°F/4%
vapor, flow of refrigerant 905 may be 128psig/44°F/14% vapor as it leaves secondary
metering device 990. Refrigerant 905 may be any suitable refrigerant, as described
above with respect to refrigerant 305 of FIGURE 3.
[0079] In operation of example embodiments of the single coil pack 900, inlet airflow 901
passes though secondary evaporator portion 940 in which heat is transferred from inlet
air 901 to the cool flow of refrigerant 905 passing through secondary evaporator portion
940. As a result, inlet air 901 may be cooled. As an example, if inlet air 901 is
80° F/60% humidity, secondary evaporator portion 940 may output first airflow at 70°
F/84% humidity. This may cause flow of refrigerant 905 to partially vaporize within
secondary evaporator portion 940. For example, if flow of refrigerant 905 entering
secondary evaporator portion 940 is 196psig/68°F/5% vapor, flow of refrigerant 905
may be 196psig/68°F/38% vapor as it leaves secondary evaporator portion 940.
[0080] The cooled inlet air 901 proceeds through coil pack 900, reaching primary evaporator
portion 910. Like secondary evaporator portion 940, primary evaporator portion 910
transfers heat from airflow 901 to the cool flow of refrigerant 905 passing through
primary evaporator portion 910. As a result, airflow 901 may be cooled to or below
its dew point temperature, causing moisture in airflow 901 to condense (thereby reducing
the absolute humidity of airflow 901). As an example, if airflow 901 is 70° F/84%
humidity, primary evaporator portion 910 may cool airflow 901 to 54° F/98% humidity.
This may cause flow of refrigerant 905 to partially or completely vaporize within
primary evaporator portion 910. For example, if flow of refrigerant 905 entering primary
evaporator portion 910 is 128psig/44°F/14% vapor, flow of refrigerant 905 may be 128psig/52°F/100%
vapor as it leaves primary evaporator portion 910. In certain embodiments, the liquid
condensate from airflow through primary evaporator portion 910 may be collected in
a drain pan connected to a condensate reservoir (e.g., as illustrated in FIGURE 4
and described herein). Additionally, the condensate reservoir may include a condensate
pump that moves collected condensate, either continually or at periodic intervals,
out of coil pack 900 (e.g., via a drain hose) to a suitable drainage or storage location.
[0081] The cooled airflow 901 leaving primary evaporator portion 910 enters secondary condenser
portion 920. Secondary condenser portion 920 facilitates heat transfer from the hot
flow of refrigerant 905 passing through the secondary condenser portion 920 to airflow
901. This reheats airflow 901, thereby decreasing its relative humidity. As an example,
if airflow 901 is 54° F/98% humidity, secondary condenser portion 920 may output an
outlet airflow 925 at 65° F/68% humidity. This may cause flow of refrigerant 905 to
partially or completely condense within secondary condenser portion 920. For example,
if flow of refrigerant 905 entering secondary condenser portion 920 is 196psig/68°F/38%
vapor, flow of refrigerant 905 may be 196psig/68°F/4% vapor as it leaves secondary
condenser portion 920. Outlet airflow 925 may, for example, enter primary condenser
portion 330 or sub-cooling coil 350 of FIGURE 3.
[0082] Although a particular implementation of coil pack 900 is illustrated and primarily
described, the present disclosure contemplates any suitable implementation of coil
pack 900, according to particular needs. Moreover, although various components of
coil pack 900 have been depicted as being located at particular positions, the present
disclosure contemplates those components being positioned at any suitable location,
according to particular needs.
[0083] In certain embodiments, secondary evaporator (340, 640) and secondary condenser (320,
620) of FIGURES 3, 6, or 8 are combined in a single coil pack such that the single
coil pack includes portions (e.g., separate refrigerant circuits) to accommodate the
respective functions of the secondary evaporator and secondary condenser. An illustrative
example of such an embodiment is shown in FIGURE 10. FIGURE 10 shows a single coil
pack 1000 which includes a secondary evaporator portion 1040 and secondary condenser
portion 1020. As shown in the illustrative example of FIGURE 10, a primary evaporator
1010 is located between the secondary evaporator portion 1040 and secondary condenser
portion 1020 of the single coil pack 1000. In this exemplary embodiment, the single
coil pack 1000 is shown as a "U"-shaped coil. However, alternate embodiments may be
used as long as flow airflow 1001 passes sequentially through secondary evaporator
portion 1040, primary evaporator 1010, and secondary condenser portion 1020. In general,
single coil pack 1000 can include the same or a different coil type compared to that
of primary evaporator 1010. For example, single coil pack 1000 may include a microchannel
coil type, while primary evaporator 1010 may include a fin tube coil type. This may
provide further flexibility for optimizing a dehumidification system in which single
coil pack 1000 and primary evaporator 1010 are used.
[0084] In operation of example embodiments of the single coil pack 1000, inlet air 1001
passes though secondary evaporator portion 1040 in which heat is transferred from
inlet air 1001 to the cool flow of refrigerant passing through secondary evaporator
portion 1040. As a result, inlet air 1001 may be cooled. As an example, if inlet air
1001 is 80° F/60% humidity, secondary evaporator portion 1040 may output airflow at
70° F/84% humidity. This may cause flow of refrigerant to partially vaporize within
secondary evaporator portion 1040. For example, if flow of refrigerant entering secondary
evaporator 1040 is 196psig/68°F/5% vapor, flow of refrigerant 1005 may be 196psig/68°F/38%
vapor as it leaves secondary evaporator portion 1040.
[0085] The cooled inlet air 1001 leaves secondary evaporator portion 1040 and enters primary
evaporator 1010. Like secondary evaporator portion 1040, primary evaporator 1010 transfers
heat from airflow 1001 to the cool flow of refrigerant passing through primary evaporator
1010. As a result, airflow 1001 may be cooled to or below its dew point temperature,
causing moisture in airflow 1001 to condense (thereby reducing the absolute humidity
of airflow 1001). As an example, if airflow 1001 entering primary evaporator 1010
is 70° F/84% humidity, primary evaporator 1010 may output airflow at 54° F/98% humidity.
This may cause flow of refrigerant to partially or completely vaporize within primary
evaporator 1010. For example, if flow of refrigerant entering primary evaporator 1010
is 128psig/44°F/14% vapor, flow of refrigerant may be 128psig/52°F/100% vapor as it
leaves primary evaporator 1010. In certain embodiments, the liquid condensate from
airflow 1010 may be collected in a drain pan connected to a condensate reservoir,
as illustrated in FIGURE 4. Additionally, the condensate reservoir may include a condensate
pump that moves collected condensate, either continually or at periodic intervals,
out of primary evaporator 1010, and the associated dehumidification system (e.g.,
via a drain hose) to a suitable drainage or storage location.
[0086] The cooled airflow 1001 leaves primary evaporator 1010 and enters secondary condenser
portion 1020. Secondary condenser portion 1020 facilitates heat transfer from the
hot flow of refrigerant passing through the secondary condenser 1020 to airflow 1001.
This reheats airflow1001, thereby decreasing its relative humidity. As an example,
if airflow 1001 entering secondary condenser portion 1020 is 54° F/98% humidity, secondary
condenser 1020 may output airflow 1025 at 65° F/68% humidity. This may cause flow
of refrigerant to partially or completely condense within secondary condenser 1020.
For example, if flow of refrigerant entering secondary condenser portion 1020 is 196psig/68°F/38%
vapor, flow of refrigerant may be 196psig/68°F/4% vapor as it leaves secondary condenser
1020. Outlet airflow 925 may, for example, enter primary condenser 330 or sub-cooling
cooling 350 of FIGURE 3.
[0087] Although a particular implementation of coil pack 1000 is illustrated and primarily
described, the present disclosure contemplates any suitable implementation of coil
pack 1000, according to particular needs. Moreover, although various components of
coil pack 1000 have been depicted as being located at particular positions, the present
disclosure contemplates those components being positioned at any suitable location,
according to particular needs.
[0088] In certain embodiments, one or both of the secondary evaporator (340, 640) and primary
evaporator (310, 610) of FIGURES 3, 6, or 8 are subdivided into two or more circuits.
In such embodiments, each circuit of the subdivided evaporator(s) is fed refrigerant
by a corresponding metering device. The metering devices may include passive metering
devices, active metering devices, or combinations thereof. For example, metering device
380 (or 690) may be an active thermostatic expansion valve (TXV) and secondary metering
device 390 (or 690) may be a passive fixed orifice device (or vice versa). The metering
devices may be configured to feed refrigerant to each circuit within the evaporators
at a desired mass flow rate. Metering devices for feeding refrigerant to each circuit
of the subdivided evaporator(s) may be used in combination with metering devices 380
and 390 or may replace one or both of metering devices 380 and 390.
[0089] FIGURES 11, 12, 13, and 14 show an illustrative example of a portion 1100 of a dehumidification
system in which the primary evaporator 1110 comprises three circuits for flow of refrigerant,
according to certain embodiments. Portion 1100 includes a primary metering device
1180, secondary metering devices 1190a-c, a secondary evaporator 1140, a primary evaporator
1110, and a secondary condenser 1120. Primary evaporator 1110 includes three circuits
for receiving flow of refrigerant from secondary metering devices 1190a-c. In the
example of FIGURES 11, 12, 13, and 14, each of secondary metering devices 1190a-c
is a passive metering device (i.e., with an orifice of a fixed inner diameter and
length). It should, however be understood that one or more (up to all) of the secondary
metering devices 1190a-c may be active metering devices (e.g., thermostatic expansion
valves).
[0090] In operation of example embodiments of portion 1100 of a dehumidification system,
flow of cooled (or sub-cooled) refrigerant is received at inlet 1102, for example,
from sub-cooling coil 350 or primary condenser 330 of dehumidification system 300
of FIGURE 3. Primary metering device 1180 determines the flow rate of refrigerant
into secondary evaporator 1140. While FIGURES 11, 12, 13, and 14 are shown to have
a single primary metering device 1180, other embodiments can include multiple primary
metering devices in parallel (e.g., if the secondary evaporator 1140 comprises two
or more circuits for flow of refrigerant).
[0091] As the cooled refrigerant passes through secondary evaporator 1140, heat is exchanged
between the refrigerant and airflow passing through secondary evaporator 1140, cooling
the inlet air. As an example, if inlet air is 80° F/60% humidity, secondary evaporator
1140 may output airflow at 70° F/84% humidity. This may cause flow of refrigerant
to partially vaporize within secondary evaporator 1140. For example, if flow of refrigerant
entering secondary evaporator 1140 is 196psig/68°F/5% vapor, flow of refrigerant may
be 196psig/68°F/38% vapor as it leaves secondary evaporator 1140.
[0092] Secondary condenser 1120 receives warmed refrigerant from secondary evaporator 1140
via tube 1106. Secondary condenser 1120 facilitates heat transfer from the hot flow
of refrigerant passing through the secondary condenser 1120 to the airflow. This reheats
the airflow, thereby decreasing its relative humidity. As an example, if the airflow
is 54° F/98% humidity, secondary condenser 1120 may output an airflow at 65° F/68%
humidity. This may cause flow of refrigerant to partially or 20 completely condense
within secondary condenser 1120. For example, if flow of refrigerant entering secondary
condenser 1120 is 196psig/68°F/38% vapor, flow of refrigerant may be 196psig/68°F/4%
vapor as it leaves secondary condenser 1120.
[0093] The cooled refrigerant exits the secondary condenser at 1108 and is received by metering
devices 1190a-c, which distributes the flow of refrigerant into the three circuits
of primary evaporator 1110. FIGURE 14 shows a view which includes the circuiting of
primary evaporator 1110. Airflow passing through primary evaporator 1110 may be cooled
to or below its dew point temperature, causing moisture in the airflow to condense
(thereby reducing the absolute humidity of the air). As an example, if the airflow
is 70° F/84% humidity, primary evaporator 1110 may output airflow at 54° F/98% humidity.
This may cause flow of refrigerant to partially or completely vaporize within primary
evaporator 1110.
[0094] Each of secondary metering devices 1190a, 1190b, and 1190c is configured to provide
flow of refrigerant to each circuit of primary evaporator 1110 at a desired flow rate.
For example, the flow rate provided to each circuit may be optimized to improve performance
of the primary evaporator 1110. For example, under certain operating conditions, it
may be beneficial to prevent the entire flow of refrigerant from passing through the
entire evaporator, as occurs in a traditional evaporator coil. Refrigerant flowing
through such an evaporator might undergo a change from liquid to gas phase before
exiting the coil, resulting in poor performance in the potion of the evaporator that
only contacts gaseous refrigerant. To significantly reduce or eliminate this problem,
the present disclosure provides for refrigerant flow at a desired flow rate through
each circuit. The desired flow rate may be predetermined (e.g., based on known design
criteria and/or operating conditions) and/or variable (e.g., manually and/or automatically
adjustable in real time) during operation. The flow rate may be configured such that
the flow of refrigerant exits its respective circuit just after transitioning to a
gas. For example, the rate of airflow near the edges of an evaporator may be less
than near the center of the evaporator. Therefore, a lower rate of refrigerant flow
may be supplied by secondary metering devices 1190a-c to the circuits corresponding
to the edge of primary evaporator 1110.
[0095] While the example of FIGURES 11, 12, 13, and 14 include a primary evaporator that
is subdivided into two or more circuits. In other embodiments, secondary evaporator
1110 may also, or alternatively, be subdivided into two or more circuits. It should
also be appreciated that the circuiting exemplified by FIGURES 11, 12, 13, and 14
can also be achieved in single coil packs such as those shown in FIGURES 9 and 10.
[0096] Although a particular implementation of portion 1100 of a dehumidification system
is illustrated and primarily described, the present disclosure contemplates any suitable
implementation of portion 1100 of a dehumidification system, according to particular
needs. Moreover, although various components of portion 1100 of a dehumidification
system have been depicted as being located at particular positions, the present disclosure
contemplates those components being positioned at any suitable location, according
to particular needs.
[0097] Herein, a computer-readable non-transitory storage medium or media may include one
or more semiconductor-based or other integrated circuits (ICs) (such, as for example,
field-programmable gate arrays (FPGAs) or application-specific ICs (ASICs)), hard
disk drives (HDDs), hybrid hard drives (HHDs), optical discs, optical disc drives
(ODDs), magneto-optical discs, magneto-optical drives, floppy diskettes, floppy disk
drives (FDDs), magnetic tapes, solid-state drives (SSDs), RAM-drives, SECURE DIGITAL
cards or drives, any other suitable computer-readable non-transitory storage media,
or any suitable combination of two or more of these, where appropriate. A computer-readable
non-transitory storage medium may be volatile, non-volatile, or a combination of volatile
and non-volatile, where appropriate.
[0098] Herein, "or" is inclusive and not exclusive, unless expressly indicated otherwise
or indicated otherwise by context. Therefore, herein, "A or B" means "A, B, or both,"
unless expressly indicated otherwise or indicated otherwise by context. Moreover,
"and" is both joint and several, unless expressly indicated otherwise or indicated
otherwise by context. Therefore, herein, "A and B" means "A and B, jointly or severally,"
unless expressly indicated otherwise or indicated otherwise by context.
[0099] The scope of this disclosure encompasses all changes, substitutions, variations,
alterations, and modifications to the example embodiments described or illustrated
herein that a person having ordinary skill in the art would comprehend. The scope
of this disclosure is not limited to the example embodiments described or illustrated
herein. Moreover, although this disclosure describes and illustrates respective embodiments
herein as including particular components, elements, feature, functions, operations,
or steps, any of these embodiments may include any combination or permutation of any
of the components, elements, features, functions, operations, or steps described or
illustrated anywhere herein that a person having ordinary skill in the art would comprehend.
Furthermore, reference in the appended claims to an apparatus or system or a component
of an apparatus or system being adapted to, arranged to, capable of, configured to,
enabled to, operable to, or operative to perform a particular function encompasses
that apparatus, system, component, whether or not it or that particular function is
activated, turned on, or unlocked, as long as that apparatus, system, or component
is so adapted, arranged, capable, configured, enabled, operable, or operative. Additionally,
although this disclosure describes or illustrates particular embodiments as providing
particular advantages, particular embodiments may provide none, some, or all of these
advantages.
1. A dehumidification system comprising:
a dehumidification unit comprising:
a primary metering device;
a secondary metering device;
a secondary evaporator operable to:
receive a flow of refrigerant from the primary metering device; and
receive an inlet airflow and output a first airflow, the first airflow comprising
cooler air than the inlet airflow, the first airflow generated by transferring heat
from the inlet airflow to the flow of refrigerant as the inlet airflow passes through
the secondary evaporator;
a primary evaporator operable to:
receive the flow of refrigerant from the secondary metering device; and
receive the first airflow and output a second airflow, the second airflow comprising
cooler air than the first airflow, the second airflow generated by transferring heat
from the first airflow to the flow of refrigerant as the first airflow passes through
the primary evaporator;
a secondary condenser operable to:
receive the flow of refrigerant from the secondary evaporator; and
receive the second airflow and output a dehumidified airflow, the dehumidified airflow
comprising warmer and less humid air than the second airflow, the dehumidified airflow
generated by transferring heat from the flow of refrigerant to the dehumidified airflow
as the second airflow passes through the secondary condenser; and
a first fan operable to generate the inlet, first, second, and dehumidified airflows;
and
a condenser unit comprising:
a second fan operable to generate a third airflow;
a sub-cooling coil operable to:
receive the flow of refrigerant from the primary condenser;
output the flow of refrigerant to the primary metering device; and
transfer heat from the flow of refrigerant to the third airflow as the third airflow
contacts the sub-cooling coil;
a primary condenser operable to:
receive the flow of refrigerant from the compressor; and
transfer heat from the flow of refrigerant to the third airflow as the third airflow
contacts the primary condenser; and
a compressor operable to receive the flow of refrigerant from the primary evaporator
and provide the flow of refrigerant to the primary condenser, the flow of refrigerant
provided to the primary condenser comprising a higher pressure than the flow of refrigerant
received at the compressor.
2. A dehumidification system comprising:
a dehumidification unit comprising:
a primary metering device;
a secondary metering device;
a secondary evaporator operable to:
receive a flow of refrigerant from the primary metering device; and
receive an inlet airflow and output a first airflow, the first airflow comprising
cooler air than the inlet airflow, the first airflow generated by transferring heat
from the inlet airflow to the flow of refrigerant as the inlet airflow passes through
the secondary evaporator;
a primary evaporator operable to:
receive the flow of refrigerant from the secondary metering device; and
receive the first airflow and output a second airflow, the second airflow comprising
cooler air than the first airflow, the second airflow generated by transferring heat
from the first airflow to the flow of refrigerant as the first airflow passes through
the primary evaporator;
a secondary condenser operable to:
receive the flow of refrigerant from the secondary evaporator; and
receive the second airflow and output a third airflow, the third airflow comprising
warmer and less humid air than the second airflow, the third airflow generated by
transferring heat from the flow of refrigerant to the third airflow as the second
airflow passes through the secondary condenser;
a sub-cooling coil operable to:
receive the flow of refrigerant from the primary condenser;
output the flow of refrigerant to the primary metering device; and
receive the third airflow and output a dehumidified airflow, the dehumidified airflow
comprising warmer and less humid air than the third airflow, the dehumidified airflow
generated by transferring heat from the flow of refrigerant to the dehumidified airflow
as the third airflow passes through the sub-cooling coil; and
a first fan operable to generate the inlet, first, second, third, and dehumidified
airflows; and
a condenser unit comprising:
a second fan operable to generate a fourth airflow;
a sub-cooling coil operable to:
receive the flow of refrigerant from the primary condenser;
output the flow of refrigerant to the primary metering device; and
transfer heat from the flow of refrigerant to the fourth airflow as the fourth airflow
contacts the sub-cooling coil;
a primary condenser operable to:
receive the flow of refrigerant from the compressor; and
transfer heat from the flow of refrigerant to the fourth airflow as the fourth airflow
contacts the primary condenser; and
a compressor operable to receive the flow of refrigerant from the primary evaporator
and provide the flow of refrigerant to the primary condenser, the flow of refrigerant
provided to the primary condenser comprising a higher pressure than the flow of refrigerant
received at the compressor.
3. The dehumidification system of Claim 1, wherein the sub-cooling coil and primary condenser
are combined in a single coil unit.
4. The dehumidification system of Claim 1, wherein two or more members selected from
the group consisting of the secondary evaporator, the primary evaporator, and the
secondary condenser are combined in a single coil pack.
5. The dehumidification system of Claim 1 or claim 2, wherein at least one of the primary
evaporator and the secondary evaporator comprises two or more circuits for flow of
refrigerant.
6. The dehumidification system of Claim 5, comprising at least one of passive and active
metering devices operable to provide subdivided flow of refrigerant to at least one
of the primary evaporator and the secondary evaporator.
7. The dehumidification system of Claim 5, wherein the primary metering device and the
secondary metering device are operable to provide subdivided flow of refrigerant to
at least one of the primary evaporator and the secondary evaporator.
8. The dehumidification system of Claim 1, wherein the second fan is operable to generate
the third airflow at an airflow flow rate of between about 2 to about 5 times an airflow
rate of the first airflow generated by the first fan.
9. The dehumidification system of Claim 1 or claim 2, wherein the secondary metering
device is operated in a substantially open state.
10. The dehumidification system of Claim 2, wherein two or more members selected from
the group consisting of the secondary evaporator, the primary evaporator, the secondary
condenser, and the sub-cooling coil are combined in a single coil pack.
11. The dehumidification system of Claim 2, wherein the second fan is operable to generate
the fourth airflow at an airflow flow rate of between about 2 to about 5 times an
airflow rate of the first airflow generated by the first fan.
12. The dehumidification system of Claim 4, wherein at least one of the primary evaporator
and the secondary evaporator comprises two or more circuits for flow of refrigerant.
13. The dehumidification system of Claim 12, comprising at least one of passive and active
metering devices operable to provide subdivided flow of refrigerant to at least one
of the primary evaporator and the secondary evaporator.
14. The dehumidification system of Claim 12, wherein the primary metering device and the
secondary metering device are operable to provide subdivided flow of refrigerant to
at least one of the primary evaporator and secondary evaporator.
15. The dehumidification system of Claim 10, wherein at least one of the primary evaporator
and the secondary evaporator comprises two or more circuits for flow of refrigerant.
16. The dehumidification system of Claim 15, comprising at least one of passive and active
metering devices operable to provide subdivided flow of refrigerant to at least one
of the primary evaporator and the secondary evaporator.