Background of the Invention
[0001] This invention relates to heating or cooling apparatus mounted within a suspended
ceiling in a home, office, or other building space. In particular, this invention
relates to the processing of air through such apparatus.
[0002] It has been heretofore known to mount a heating or cooling apparatus in a suspended
ceiling of a room or space that is to be heated or cooled. The thus mounted apparatus
typically draws air in through an inlet provided in the apparatus. The thus drawn
in air is circulated through appropriate heat exchange elements before exiting through
one or more outlets provided in the apparatus.
[0003] The ceiling mounted apparatus typically includes a fan device for drawing in the
air that is to be processed and discharged. This fan device may create a significant
suction pressure at the air inlet. This suction pressure can draw the air being discharged
from the ceiling mounted apparatus back into the apparatus. Re-circulation of this
discharged air back through the heat exchange elements lowers the heating or cooling
efficiency of the apparatus. It may also affect the long term integrity of the heat
exchange elements that are being exposed to the re-circulated air that does not need
to be further heated or cooled.
[0004] The potential for re-circulation of discharged air back through an air intake of
a ceiling mounted apparatus has been heretofore addressed by providing air outlets
that direct the discharged air away from the air intake. It has however been found
that this directional discharge is hard to achieve when the air outlets are relatively
close to the air inlet.
[0005] It is an object of the invention to provide heating or cooling apparatus mounted
within a suspended ceiling that maintains a proper distribution of either heated or
cooled air that does not interfere with the intake of air into the same apparatus.
[0006] It is another object of the invention to provide heating or cooling apparatus for
mounting within a suspended ceiling that defines two distinct air flow paths for conditioned
air leaving the apparatus that achieve optimal air flow for both heated and cooled
air from the ceiling mounted apparatus.
Summary of the Invention
[0007] The above and other objects are achieved by a ceiling mounted heating or cooling
apparatus that draws air upwardly into an inlet and processes the air through heat
exchange elements before distributing the air downwardly. The air is preferably distributed
downwardly by air discharge structure surrounding the heat exchange elements. The
air is ultimately discharged through one or more air discharge ducts positioned relatively
close to the air inlet. Each discharge duct includes a rotatable louver mounted therein
that guides the air within the duct.
[0008] The rotatable louver in each air discharge duct preferably rotates between either
of two positions depending on whether warm or cool air is to be discharged. The position
of the louver when warm air is to be discharged produces a substantially downward
air flow path to the air exiting the duct. The position of the louver when cool air
is to be discharged produces a substantially lateral air flow path to the air exiting
the duct.
[0009] The air is preferably discharged at a minimum distance from the ceiling so as to
avoid any smudging of the ceiling. This is accomplished by a gradually curved wall
in each air duct that extends laterally outwardly so as to define were the air exits
from the duct at the minimum distance from the ceiling.
[0010] Another wall of each discharge duct preferably includes a smoothly curved bend of
a prescribed angular arc that directs the discharged air away from the air inlet of
the apparatus. This wall in each duct is relatively close to the air inlet.
Brief Description of the Drawings
[0011] Other objects and advantages of the present invention will be apparent from the following
description in conjunction with the accompanying drawings, in which:
Figure 1 illustrates a ceiling mounted heating and cooling apparatus having air discharge
slots located around the perimeter of a centrally located air intake grill;
Figure 2 illustrates the heating and cooling apparatus prior to being mounted in the
ceiling of Figure 1;
Figure 3 is an exploded view of the heating and cooling apparatus of Figure 2;
Figure 4 is a sectional view of the heating and cooling apparatus of Figures 2 and
3 illustrating how air is processed from the intake grill to the output of an air
discharge duct;
Figure 5 is an enlarged cross-sectional view of the air discharge passage formed in
the bottom most piece of the heating and cooling apparatus of Figures 2 and 3; and
Figure 6 is an enlarged cross-sectional view of the air discharge passage of Figure
5 when the rotated louver therein is in a position for distributing heated air.
Preferred Embodiment
[0012] Referring to Figure 1, a ceiling mounted apparatus 10 for heating or cooling air
is illustrated in mounted position with respect to a ceiling 12. The apparatus is
seen to include a centrally located air intake grill 14, which allows air to be drawn
in from the space being heated or cooled. The heating and cooling apparatus also includes
four air discharge slots 16, 18, 20 and 22. These air discharge slots each form part
of respective air discharge ducts which distribute processed air from the apparatus
back into the space being heated or cooled. It is to be noted that each discharge
slot is located relatively close to the centrally located grill 14.
[0013] Referring to Figure 2, the beating and cooling apparatus 10 is shown before being
mounted within the ceiling 12. It is to be noted that the heating and cooling apparatus
includes a housing 24 containing the various components for processing the air that
is drawn into the apparatus through the air intake grill 14.
[0014] Referring to Figure 3, the heating and cooling apparatus 10 is illustrated in an
exploded view form. The bottom portion of the heating and cooling apparatus is seen
to include a frame 26 in which four air discharge ducts, such as duct 28, are formed
therein. Each discharge duct defines one of the respective discharge slots 16, 18,
20 and 22 in the frame 26. A rotatable louver such as 30 is positioned within each
air discharge duct. The rotatable louver 30 is seen to extend along the entire length
of the duct 28.
[0015] An air filter 32 and the intake grill 14 preferably fit into a central opening in
the frame 26 and are appropriately secured thereto. The intake grill 14 is preferably
square in shape and is curved slightly upwardly toward its center from all four sides.
[0016] A centrifugal fan 34 draws air upwardly through the intake grill 14 and the air filter
32. This fan distributes the drawn up air radially outwardly toward heat exchange
elements 36.
[0017] The heat exchange elements preferably consist of a series of coils arranged around
the periphery of the centrifugal fan. These coils carry a heat exchange medium which
transfers heat to or from a series of heat exchange fins in thermal conducting contact
with the coils.
[0018] The outwardly flowing air from the centrifugal flow fan 32 is deflected downwardly
by air channel structure 38 as shown in Figure 4. The air channel structure 38 is
preferably molded out of polystyrene so as to form a single light insulative piece
that fits into the housing 24. The air channel structure 38 is seen to extend inwardly
along a top portion 40 of the heating and cooling apparatus to a point beyond the
inner perimeter of the fins of the heat exchange elements. The air channel structure
also extends downwardly along the inner wall of the housing 24. The air channel structure
38 also is slanted toward the inner wall of the housing 24 so as to define a continuously
increasing radial spacing from the heat exchange elements. The air channel structure
38 extends downwardly at this definable slant to the top of a drain pan 42 that is
more clearly shown in Figure 3.
[0019] Referring again to Figure 4, the bottoms of the fins of the heat exchange elements
36 rest in the drain pan 42 so as to allow any condensate from the coils of the heat
exchange elements to be collected and drained away in a slot 44. A slotted hole 45
in the drain pan is aligned with respect to the air channel structure 38 so as to
define a continuous air channel down to the air duct 28 formed in the frame 26. It
is to be noted that similar slotted holes in the drain pan define continuous air channels
down to the other respective air discharge ducts in the frame 26.
[0020] The cross-section of the frame in Figure 4 reveals that the frame consists of two
different structures. The frame includes an exterior portion 46 preferably molded
of a hard plastic. The frame furthermore includes a lightweight molded polystyrene
structure 47 above the exterior portion 46.
[0021] Referring again to the air channel structure 38, it is to be noted that this structure
forms a continuous, smooth, inner wall surface for deflecting the air downwardly.
The upper portion of this continuous, smooth, inner wall surface is preferably a curved
arc having a constant radius of curvature. The slanted portion of this inner wall
is preferably three to five degrees from the vertical. This smooth continuous inner
wall assures that all air flows smoothly down to the slotted hole 46 in the drain
pan and hence to the air passage duct 28 formed in the frame 26.
[0022] Referring to the heat exchange elements 36, it is to be appreciated that these elements
will either add heat or remove heat from the air passing over the fins depending on
the state of the heat exchange medium flowing through the coils of the heat exchange
elements. In this manner, the heating or cooling apparatus will either provide warm
or cool air to the air discharge ducts in the frame 26. Referring to the air discharge
duct 28 in Figure 4, it is to be noted that the louver 30 is attached at each end
to rotatable members such as 48 which rotates within a bracket 50. As will be explained
in detail hereinafter, the louver 30 is rotated to either of two positions depending
on whether warm or cool air is flowing through the air discharge duct 28. The rotation
of the louver 30 may either be by a motor or through manual adjustment. It is to be
appreciated that similar louvers are rotatably mounted and driven to respective positions
in each of the other air discharge ducts formed in the frame 26.
[0023] Referring to Figure 5, the discharge duct 28 within the frame 26 is further illustrated
in an enlarged cross-sectional view. The air discharge duct 28 is seen to comprise
two continuous wall surfaces denoted as an inner wall surface 52 and an outer wall
surface 54. The inner wall surface 52 is relatively close to the intake grill 14 whereas
the outer wall surface 54 is further away from the grill. The outer wall surface 54
is seen to be a part of the frame 26 that extends outwardly in a lateral direction
away from the portion of the frame 26 that fits up into the ceiling. This portion
of the frame forms a lip 56 that generally fits up against the ceiling when the heating
or cooling apparatus is mounted thereto. It is to be noted that the outer wall 54
extends outwardly to a point located at a distance "h" below the top of the lip 56.
The distance "h" is preferably in the range of fifteen to twenty millimeters. This
height assures that no smudging will occur to the ceiling when air flows out along
the smoothly curved wall 54. It is finally to be noted that the beginning of the outer
wall surface 54 is substantially vertical before sharply curving to a point where
the lip 56 begins. This point is vertically below where the frame 26 fits into the
ceiling. The outer wall surface continues almost laterally from this point at a substantially
large radius of curvature until reaching the discharge point at the distance "h" below
the top of the lip 56 of the frame 26.
[0024] Referring now to the inner wall 52, it is to be noted that this wall begins within
the frame 26 upstream of where the louver 30 is rotatably mounted within the duct
28. This wall slits slightly from vertical to a point vertically below the horizontal
plane containing the axis of rotation of the rotatable member 48. The inner wall 52
thereafter comprises a substantially curved arc before tangentially meeting a straight
slanted wall surface immediately upstream of the exit point of the air from the duct
28.
[0025] It is to be noted that the total angular change of the inner wall 52 from the first
slanted portion of this wall beginning where the duct 28 is formed in the frame 26
to the second slanted straight wall portion ending where the air exits from the duct
28 is denoted by the angle α. This angle is determined by the curved arc portion of
the inner wall 52 that joins the first and second slanted wall portions of the inner
wall. This angular change in the inner wall 52 is preferably within the range of one
hundred ten to one hundred thirty degrees. It has been found that when α is greater
than one hundred thirty degrees, there is the potential for re-circulation of the
air back into the inlet grill 14. It has also been found that when α is less than
one hundred ten degrees, there is a poor discharge of heated air.
[0026] Referring now to the rotatably mounted louver 30, it is seen that this louver comprises
two leg portions joined together by a curved arc portion therebetween. The curved
arc portion defines an angle β between the two straight leg portions of the louver.
The curved arc portion preferably has a constant radius of curvature so that the angle
β defines the total angular measurement in degrees of arc defined by such a radius.
The angle β is preferably in the range of one hundred ten to one hundred twenty degrees.
[0027] The two straight leg portions of the louver 30 preferably define linear dimensions
"A" and "B". These linear dimensions are defined by extending the center lines of
these leg portions until they intersect at a point in the vicinity of the curved arc
portion. The dimension "A" is measured from the tip of the upper leg portion along
the center line of this upper leg portion of the louver to the aforementioned point
of intersection of the center lines. The dimension "B" is measured along the center
line of the lower straight leg portion from the aforementioned point of intersection
to the tip of the lower leg of the louver. The ratio "A/B" of these dimensions is
preferably in the range of 0.4 to 0.6. It has been found that an A/B ratio of less
than 0.4 produces poor discharge of air with the potential for re-circulation problems
with respect to the air intake grill 14. An A/B ratio greater than 0.6 creates a louver
that is too sensitive to rotational positioning.
[0028] It is to be noted that the louver 30 is shown in Figure 5 in its normal position
for processing cooled air within the air discharge duct 28. In this regard, the point
of intersection of the dimensioned lengths "A" and "B" of the louver is preferably
at a lateral distance "F" from the point of the inner wall 52 where the curved arc
portion begins. The point of intersection of the lengths "A" and "B" of the louver
is also at a lateral distance "G" from the top most point of the outer wall 54. The
ratio of these dimensions, F/G, is preferably between 0.8 and 1.2.
[0029] The lower leg of the louver 30 during cooling is preferably at an angle γ of sixty
to seventy-five degrees from vertical. This angle allows for substantial air flow
to either side of the louver. This thus positioned louver produces a directional discharge
of air from the duct 28 defined by the angle δ. The angle δ as measured from horizontal
will be between five and twenty degrees when the lower leg of the louver is at the
angle γ.
[0030] Referring now to Figure 6, the louver 30 is illustrated in the heating mode position.
In this regard, the louver 30 has been preferably rotated clockwise by twenty-five
degrees from the cooling mode position so that the lower leg portion moves toward
the inner wall 52 whereas the upper leg portion moves towards the outer wall 54. The
lower leg portion of the louver 30 is now at a angle κ of thirty-five to fifty degrees
from vertical. The thus positioned louver now tends to deflect the air from its otherwise
normal outward flow dictated by the slant of the inner wall 52 at the air exit point
from the duct 28. In this regard, the lower leg of the louver 30 tends to deflect
the heated air substantially downwardly with less of a lateral component than when
the louver 30 is in the cooling mode position. The angle of discharge, θ, is preferably
in the range of forty to fifty-five degrees from horizontal. It is to be noted that
this angle has a lateral component that is substantially less than the lateral component
of the angle δ defining the air discharge direction in the cooling mode.
[0031] Referring to the inner wall 52 and, in particular, to the angular slope of this wall
near the exit point of the air from the duct 28. This angular slope is denoted as
φ in Figure 6. This angle as measured from vertical is preferably midway between a
given value of κ and a given value of γ used in a particularly designed duct. This
normally results in the angle φ being in the range of fifty-five to sixty-five degrees.
This allows the air flow closest to the inner wall to have a substantial lateral component
in both heating and cooling so as to reduce the risk of any recirculating air to the
air intake grill 14.
[0032] Referring again to the angles α and β, denoting the angular arc of curvature of the
inner wall surface 52 and the louver 30, respectively. It is to be noted that these
angular arcs allow for a substantial air flow along the inner wall 52 of the air duct
28 in both heating and cooling. If the angle α of the arc of the inner wall is however
less than one hundred-ten degrees, then the exit slope angle φ of this wall increases
thereby producing excessive pressure loss on the inner wall side of the louver during
heating mode. On the other hand, if the angle α is greater than one hundred-thirty
degrees, then the exit slope φ decreases to the point where discharged air may recirculate
into the grill.
[0033] It is to be appreciated that the thus shaped air duct passage 28 in combination with
the thus shaped louver 30 defines two separate distinct air paths to either side of
the louver. These paths produce a first directional air discharge for cooling versus
cooling a second directional discharge for heating. The air discharge path for cooling
moves the air substantially laterally outwardly from the apparatus so as to avoid
creating a cold draft on people within the room being cooled by the ceiling apparatus.
In contrast, the air discharge in heating is substantially more downward to counteract
the tendency of heated air to normally rise and thereby not circulate toward the people
in the room.
[0034] It is to be finally appreciated that a preferred embodiment of the invention has
been described. Alterations, modifications and improvements thereto will readily occur
to those skilled in the art. Accordingly, the foregoing is by way of example only
and the invention is to be limited only by the following claims and equivalents thereto.
1. Ceiling mountable apparatus for heating or cooling air, said apparatus comprising:
an external housing;
a frame containing an air inlet, said frame fitting into said external housing;
a fan within the external housing for drawing air up through the air inlet in said
frame and for subsequently distributing the drawn in air radially outwardly;
a plurality of heat exchange elements positioned radially outwardly of said fan for
heating or cooling the radially distributed air from said fan;
air channel structure positioned within the external housing relative to said fan
so as to deflect the radially distributed air from said fan downwardly; and
at least one air discharge duct in said frame containing the air inlet, said discharge
duct having a first wall located near at least one edge of the air inlet and a second
wall opposite said first wall which is located further outwardly from the edge of
the air inlet than said first wall, wherein said first and second walls are smooth,
continuous walls formed in said frame.
2. The apparatus of claim 1 wherein said first wall in said discharge duct comprises
a first straight wall portion followed by a curved wall portion followed by a second
straight wall portion terminating where air is discharged from the discharge duct.
3. The apparatus of claim 2 wherein the curved wall portion of said First wall defines
an angular arc in the range of one hundred ten to one hundred thirty degrees between
said first and second straight portions of said first wall.
4. The apparatus of claim 3 wherein the second straight wall portion terminating where
air is discharged from the discharge duct is at an angle from vertical in the range
of fifty-five to sixty-five degrees.
5. The apparatus of claim 3 further comprising:
a rotatable louver mounted within said discharge duct, said rotatable louver having
first and second straight leg portions which are joined together by a curved arc portion
therebetween.
6. The apparatus of claim 5 wherein said curved arc portion between said first and second
straight leg portions comprises an arc in the range of one hundred ten to one hundred
twenty degrees.
7. The apparatus of claim 6 wherein the centerlines of said first and second straight
leg portions intersect at a point so as to define a first linear dimensional length
"A" along the centerline of the first leg from the point of intersection to the tip
of said first leg and a second linear dimensional length "B" along the centerline
of the second leg from the point of intersection to the tip of the second leg and
wherein the ratio of A/B is within the range of 0.4 to 0.6.
8. The apparatus of claim 7 wherein the rotatable louver is rotatable to a first position
when the air is being cooled by said heat exchange elements whereby the point of intersection
of said first and second center lines is at a horizontal distance, "F", from the point
of the first wall where the first straight wall portion ends and the curved wall portion
begins and at a horizontal distance, "G", from the top point of the second wall formed
in the frame wherein the ratio of F/G is 0.8 to 1.2.
9. The apparatus of claim 8 wherein the second straight leg portion of said rotatable
louver is at an angle from vertical of between sixty and seventy-five degrees when
said rotatable louver is in the first position.
10. The apparatus of claim 9 wherein said rotatable louver is rotatable to a second position
when the air is being heated by said heat exchange elements wherein the second straight
leg portion of said rotatable louver is at an angle from vertical of between thirty-five
and fifty degrees.
11. The apparatus of claim 6 wherein said rotatable louver is rotatable to a first position
when the air is being cooled by said heat exchange elements wherein the second straight
leg portion of said rotatable louver is at an angle from vertical between sixty and
seventy-five degrees.
12. The apparatus of claim 11 wherein said rotatable louver is rotatable to a second position
when the air is being heated by said heat exchange elements wherein the second straight
leg portion of said rotatable louver is at an angle from vertical of between thirty-five
and fifty degrees.
13. The apparatus of claim 1 wherein the second wall in said discharge duct includes a
continuously curved portion extending laterally outwardly toward an outer edge of
said flame, said curved portion defining the closest air exit point to a ceiling surface
when the ceiling mountable apparatus is mounted to a ceiling.
14. The apparatus of claim 13 wherein the closest air exit point to a ceiling surface
is at a vertical distance from the ceiling surface that is within a range of fifteen
to twenty millimeters.
15. The apparatus of claim 1 wherein said air channel structure positioned within the
external housing comprises:
a continuous structure surrounding said heat exchange elements and radially spaced
therefrom at increasing radial distances as said continuous structure extends downwardly
from a point above said heat exchange elements to a point below said heat exchange
elements.
16. The apparatus of claim 15 wherein said continuous structure furthermore curves radially
inwardly above said heat exchange elements so as to define a smooth curved air channel
beginning above said heat exchange elements.