U.S. patent application number 10/298957 was filed with the patent office on 2004-05-20 for modular self contained unit ventilator.
This patent application is currently assigned to PEF Industries, Inc.. Invention is credited to Harshberger, Martin J., Hicks, Steven G., Welch, Timothy D..
Application Number | 20040094289 10/298957 |
Document ID | / |
Family ID | 32297572 |
Filed Date | 2004-05-20 |
United States Patent
Application |
20040094289 |
Kind Code |
A1 |
Harshberger, Martin J. ; et
al. |
May 20, 2004 |
Modular self contained unit ventilator
Abstract
A unit ventilator is described in which air treating apparatus
is housed within a chassis which is readily removable from a
fixedly installed cabinet. The air treating apparatus includes an
evaporator, a compressor, a condenser and an air flow system for
separately handling air for ventilating and air for condenser
cooling and in which the system for condenser cooling provides for
evaporative cooling of the refrigerant. The invention contemplates
modular system arrangements in which the use of plural chassis in
an installation enables the production of a wide range of
ventilating capacity from minimal change in alternative chassis
modules.
Inventors: |
Harshberger, Martin J.;
(Germantown, TN) ; Hicks, Steven G.; (Cordova,
TN) ; Welch, Timothy D.; (Grand Junction,
TN) |
Correspondence
Address: |
ARMSTRONG, KRATZ, QUINTOS, HANSON & BROOKS, LLP
1725 K STREET, NW
SUITE 1000
WASHINGTON
DC
20006
US
|
Assignee: |
PEF Industries, Inc.
Somerville
TN
|
Family ID: |
32297572 |
Appl. No.: |
10/298957 |
Filed: |
November 19, 2002 |
Current U.S.
Class: |
165/48.1 ;
165/137; 165/58; 62/262 |
Current CPC
Class: |
F24F 2013/225 20130101;
F24F 13/20 20130101; F24F 1/027 20130101 |
Class at
Publication: |
165/048.1 ;
165/058; 165/137; 062/262 |
International
Class: |
F25B 029/00; F28F
007/00; F25D 023/12 |
Claims
1. A modulator unit ventilator, comprising: a cabinet having
substantially rectangularly disposed panels forming a fixed
enclosure, one of said cabinet panels being detachable to provide
access to the interior of said cabinet; at least one slide-in
chassis having substantially rectangularly disposed walls and being
sized to be readily inserted and removed with respect to the
interior of said cabinet; one of said chassis walls being
detachable to permit access to the interior thereof; a partition
dividing said chassis into an evaporator section and a condenser
section containing an evaporator coil and a condenser coil,
respectively; a ventilated air discharge opening from said
evaporator section and condenser air discharge opening from said
condenser section; air handling means including a first blower
disposed on one side of said partition for passing input air to
said evaporator section and thence to discharge into said space to
be ventilated, and a second blower disposed on the other side of
said partition for circulating condenser air with respect to said
condenser; and inlet means for supplying input air to said first
and second blowers, respectively.
2. A modulator unit ventilator, according to claim 1, in which said
input air inlet means includes mutually spaced openings in both
said cabinet and said chassis defining opening means for receiving
outside air and for distributing said outside air to said
evaporator and condenser sections of said chassis.
3. A modulator unit ventilator, according to claim 2, in which said
input air inlet means includes openings in said cabinet and chassis
for supplying return air to said evaporator section of said
chassis.
4. A modulator unit ventilator, according to claim 3, including a
roll damper mounted for pivotal movement in said evaporator section
of said chassis and being operative to proportion amounts of
outside air and return air to said evaporator section.
5. A modulator unit ventilator, according to claim 2, including a
partition plate disposed in said condenser section of said chassis
for dividing intake air flow into a first portion passing to said
condenser section and a second portion passing to said evaporator
section.
6. A modulator unit ventilator, according to claim 5, in which said
partition plate is formed as a condensate collector positioned
adjacent said second blower, said blower being thereby operative to
circulate a moisture-laden air flow in heat transfer relation with
respect to said condenser.
7. A modulator unit ventilator, according to claim 6, including a
condensate collection trough arranged to collect condensate
generated by said evaporator; and a conductor extending from said
collection trough to supply condensate to said condensate
collector.
8. The modulator unit ventilator according to claim 4 in which an
opening in said partition is oppositely spaced from said opening
for supplying return air to said evaporator section, said roll
damper being mounted for pivotal movement between said partition,
and means for adjusting the position of said roll damper opening
and said return air opening for selectively supplying outside air
and return to said evaporator section.
9. The modulator unit ventilator, according to claim 8, wherein
said partition opening and said return air opening are mutually
oppositely spaced with respect to each other; filter plates
disposed adjacent each of said openings; and said roll damper
having seal members cooperable with each of said filter plates for
adjustably determining the composition of air flow into said
evaporator sections.
10. The modulator unit ventilator, according to claim 9, including
a partition defining a filter door upstanding from a bottom of said
chassis, said filter door being cooperable with said roll damper
for directing the flow of input air through said evaporator
section.
11. The modulator unit ventilator, according to claim 10, wherein
said filter door is mounted for pivotal movement with respect to
said chassis whereby said filter door is movable to permit access
to said filter plates when said one chassis wall is detached.
12. The modular unit ventilator, according to claim 1, including
trough means operative to receive condensate generated on a surface
of tubes forming said evaporator coil and to deliver said
condensate to said second blower to be passed in mixed relation to
input air in heat transfer relation with respect to said condensate
coil.
13. The modular unit ventilator, according to claim 12, in which
said trough means includes a first trough positioned to receive
condensate generated on surfaces of said evaporator coil tubes, a
second trough positioned in proximity to said second blower, means
for transferring condensate from said first trough to said second
trough for delivery with input air in heat transfer relation to
second condenser coil.
14. A modular unit ventilator, according to claim 1, including
independently operable air heating means disposed immediately
upstream from said air discharge opening from said evaporator
section.
15. A modular unit ventilator, according to claim 14, in which said
air heating means comprises electrically operated heating
elements.
16. A modular unit ventilator according to claim 14 in which said
air heating means comprises a hydronic coil.
17. A modular unit ventilator, according to claim 1, in which said
cabinet contains a plurality of slide-in chassis disposed in
side-by-side relation, said chassis being each independently
arranged for selective insertion and removal thereof with respect
to the interior of said cabinet.
18. A method of constructing a modular unit ventilator containing a
cabinet having substantially rectangularly disposed panels forming
a fixed enclosure, one of said cabinet panels being detachable to
provide access to the interior of said cabinet and a plurality of
slide-in chassis being sized to be readily inserted and removed
from said cabinet, and said chassis having one wall detachable to
permit access to the interior thereof, an evaporator coil, a
condenser coil and air handling means for passing input air to said
evaporator coil and said condenser coil, respectively, and return
air to said evaporator coil, said method comprising the steps of:
providing each of said chassis with corresponding organization of
operating elements; and determining the number and design capacity
of said chassis for a cabinet to provide an accumulated design
capacity for the cabinet.
19. The method of constructing a modular unit ventilator, according
to claim 18, including the step of providing at least two of said
chassis of different design capacities.
Description
[0001] The present invention relates to unit ventilators containing
equipment for discharging either cooled or heated air into a space
to be ventilated. More particularly, the invention concerns a unit
ventilator apparatus in which the principle operating parts of the
apparatus are characterized by component modularization whereby,
due to apparatus design, the operating parts are all collectively
housed in a chassis which is readily installed or removed from the
ventilator cabinet. Consequently, replacement or repair of
apparatus components can be effected with a minimum of system
downtime. Moreover, the invention contemplates installation of a
plurality of chassis, each containing the same or substantially the
same apparatus whereby, in addition to facilitating apparatus
design by the use of modules, in the event of malfunction or other
need for removal of a chassis from operation, space ventilation can
continue on a partial capacity basis.
BACKGROUND OF THE INVENTION
[0002] Unit ventilators are commonly used for the ventilation of
school classrooms or other confined spaces characterized by high
density occupancy. Although the principle function of equipment of
the concerned type is to provide ventilation cooling by selectively
blowing cool outside air into the concerned space, it is frequently
found to be desirable to process the air either by mechanically
conditioning the air by cooling or by heating it before discharging
it from the ventilator. Moreover, it is oftentimes desired that the
air be totally or proportionately recirculated, either as fresh
incoming air or as air that has been heated or cooled, in order
that a high incidence of fresh air ventilation is achieved.
[0003] Consequently, such unit ventilators have usually included a
cabinet enclosure in which the component ventilator parts are
housed, the ventilator parts including such air conditioning
components as evaporator and condenser coils, appropriate blowers
for circulating fresh outside air and/or recirculated air in
regulated amounts between the respective coils and a compressor for
processing the refrigerating fluid. Heating units of an
electrically-or fluid-operated variety may also be provided where
it is desired to provide the ventilating system with a heating as
well as a cooling capability.
[0004] Air conditioning systems of the prior art, particularly
those having an alternate heating capability, have been
characterized by complex equipment configurations having high
initial costs and being expensive to maintain, the expense of which
is compounded when it is considered that malfunctions of one or
more sections or components of the unit may require extensive
periods of inoperativeness while the defective system components
are repaired or replaced. Commonly with ventilating units of such
prior design, the occasion of equipment failure or malfunction
necessitates either termination of occupancy of the affected
ventilated space or, alternatively, the use of less effective
ventilating apparatus at an increased cost during periods of
equipment unavailability.
[0005] It is to the amelioration of the foregoing problems to which
the present invention is directed.
SUMMARY OF THE INVENTION
[0006] Accordingly, it is a principle object of the invention to
provide a unit ventilator having an air conditioning capability
and, if desired, an alternatively operable heating capability.
[0007] It is another object of the invention to provide a unit
ventilator of modular design in which the operating components of
the system are housed within a chassis enclosure which enables
rapid removal and installation of such components during instances
of a need for equipment maintenance, repair or replacement.
[0008] A still further object of the invention is to provide a unit
ventilator organization in which the design of ventilators of
elevated capacities can be accomplished merely by use of selected
multiple modules of predetermined design capacities.
[0009] It is a further object of the invention to provide a unit
ventilator of modular configuration whereby the engineering and
design of ventilators having increased capacity is facilitated by
the selective use of plural chassis modules.
[0010] Yet another objective of the invention is to provide a unit
ventilator employing plural chassis modules whereby removal of a
chassis for service does not prevent reduced capacity operation of
the ventilator through the use of the components remaining in the
chassis.
[0011] These and other objects and advantages are provided by the
hereinafter described modular unit ventilator system which includes
a cabinet having substantially rectangularly disposed panels
forming a fixed enclosure, one of said cabinet panels being
detachable to provide access to the interior of said cabinet; at
least one slide-in chassis having substantially rectangularly
disposed walls and being sized to be readily inserted and removed
with respect to the interior of said cabinet; one of said chassis
walls being detachable to permit access to the interior thereof; a
partition dividing said chassis into an evaporator section and a
condenser section containing an evaporator coil and a condenser
coil, respectively; a ventilated air discharge opening from said
evaporator section and condenser air discharge opening from said
condenser section; air handling means including a first blower
disposed on one side of said partition for passing input air to
said evaporator section and thence to discharge into said space to
be ventilated, and a second blower disposed on the other side of
said partition for circulating condenser air with respect to said
condenser; and inlet means for supplying input air to said first
and second blowers, respectively.
[0012] The described unit ventilator incorporates a selectively
adjustable damper for circulating input air consisting of regulated
amounts of either or both outside air and/or room return air
through the evaporator. Moreover, equipment organization is such
that moisture represented by condensate collected from air flowing
in heat exchange relation with respect to the evaporator coil is
mixed with cooling air for effecting more efficient heat transfer
via evaporative cooling of the operating refrigerant in the
condenser coil.
[0013] The invention further involves a more flexible unit
ventilator design wherein, depending upon desired design capacity,
a plurality of independently operated modules of corresponding
organization can be utilized in a ventilator cabinet of
accommodating size. As a result, not only is continued operation of
an installation permitted, albeit at a reduced capacity, in
instances of removal from service of a chassis module, but an
enhancement of equipment design and engineering is achieved from
the use of modules of corresponding design which may be of the same
or disparate design capacities.
[0014] For a better understanding of the invention, its operating
advantages and the specific objects obtained by its use, reference
should be made to the accompanying drawings and description which
relate to preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a general exploded perspective view of a modular
unit ventilator according to an embodiment of the present
invention;
[0016] FIG. 2 is a more detailed exploded view of the embodiment of
FIG. 1;
[0017] FIG. 3 is a somewhat schematic elevational section view of
the embodiment of FIG. 1;
[0018] FIG. 4 is a somewhat schematic front perspective view of the
chassis portion of the invention embodiment shown in FIG. 1;
[0019] FIG. 5 is a somewhat schematic rear perspective view of the
chassis portion of the invention embodiment shown in FIG. 1;
and
[0020] FIG. 6 is a view, similar to FIG. 2, showing another
embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0021] With particular reference to the drawings wherein like
reference numerals designate like parts throughout the respective
views, there is shown in FIG. 1 an exploded general representation
of a modular unit ventilator 10 constructed according to the
present invention. The illustrated unit ventilator 10 includes a
cabinet 12, and a chassis 14 wherein all of the principle operating
parts of the unit ventilator of the invention are contained. The
cabinet 12 has a readily detachable front panel 16 that, when
removed from the cabinet frame, exposes the chassis 14 for ready
removal from the cabinet upon disconnection of the plug 18 which
connects the chassis to a source of electric power and control box
54. Handles 17 may be provided on the chassis front panel 16 to
assist in moving the chassis with respect to the cabinet.
[0022] As best shown in FIG. 2, the cabinet 12 comprises a frame
structure, indicated generally as 20, that includes laterally
elongated front and rear struts 22 forming a base 24. Members
comprising end ties 26 extend between and connect together opposite
ends of the respective struts 22. A plurality of chassis-support
rails 28 extend between and connect the respective struts 22 at
intermediate locations along the length of the cabinet 12. A pair
of end panels 30 close the opposite ends of the frame structure 20,
and a pair of side plates 32 extend between the base 24 and an
elevated roof support 34 at locations spaced inwardly from the end
panels. The roof support 34 contains an elongated opening 36 and is
covered by a roof panel 38 having an opening 40 containing a grille
42 which align with the opening 36 from which processed air is
discharged from the ventilator.
[0023] The rear of the cabinet 12 is essentially open and is
adapted to be fixedly disposed with respect to the outside wall 44
of a building, or the like, shown in FIG. 3 as being provided with
a pair of vertically spaced openings 46 and 48 which may be
separated by an intermediate wall portion 50. A grill 52 depends
from the lower edge of the cabinet front panel 16 and is adapted to
pass return air from the ventilated space to the chassis 14 for
reprocessing, as hereinafter more fully described.
[0024] Preferably, the cabinet side plates 32 are laterally spaced
inwardly from the end panels 30 in order to provide storage areas
33 at opposite ends of the cabinet 12 for accommodating equipment,
as for example, the control box 54.
[0025] The chassis 14 comprises an enclosure structure formed of
generally rectangularly disposed walls including a base 56, a front
wall 58, a rear wall 60, side walls 62 and a sectioned roof 64. A
downwardly inclined grate 66 extends substantially parallel to, and
communicates with, the grill 52 on the cabinet front panel 16 to
permit passage of return air to the ventilator apparatus, as
hereinafter described. An opening 67 is provided in the cabinet
roof 64 and communicates with the opening 36 in the cabinet roof
support 34 to define a processed air outlet from the unit
ventilator 10.
[0026] The interior of the chassis 14 contains the elements of a
ventilating system for processing air admitted to the apparatus.
For this purpose, as best shown in FIGS. 3 to 5, the chassis
interior is divided into an evaporator section 68 and a condenser
section 70, which sections are separated by a partition plate 72
that stands uprightly from the chassis base 56.
[0027] The evaporator section 68 is divided vertically by a
horizontally disposed support plate 74 for a motor board assembly
76 which includes a laterally spaced pair of cylindrical blowers 78
for circulating air to be processed through openings 79 in the
motor board support plate 74, which openings define blower
discharge outlets to that region of the evaporator section 68
containing the evaporator coil 86 through which the air to be
processed passes prior to discharge from the roof openings 36 and
67 in the cabinet 12 and chassis 14, respectively. As shown, the
motor board support plate 74 is an elongated member which extends
from end-to-end of the evaporator section 68 and suspends from the
underside thereof by means of bolts 80, an electric drive motor 82
having oppositely extending drive shafts (not shown) for connection
with longitudinally spaced blowers 78, between which the drive
motor is positioned. In the disclosed embodiment of the invention,
the motor board assembly 76,is shown as comprising two blowers 78
between which a single drive motor 82 is positioned. It should be
appreciated, however, that the number of drive motors and the
number of blowers to be employed can be increased or decreased
based upon the design capacities of the blowers and drive motors
selected.
[0028] The upper region of the evaporator section 68 contains the
evaporator coil 86, which is elongated laterally, and is defined by
a plurality of parallel refrigerant-conducting tubes 88 that extend
between headers 90. A condensate collection tray 92 is positioned
along the lower end of the evaporator coil 86 and is adapted to
receive liquid droplets resulting from the condensation of moisture
extracted from the air processed by the evaporator.
[0029] The upper region of the evaporator section 68 may, as shown
in FIG. 3, optionally contain heating elements which may be
electrically operated heating units 95 and/or a hydronic heater 93
for processing air in the ventilator by heating, instead of
cooling.
[0030] The condenser section 70 of the ventilator is disposed on
the rear side of the partition plate 72 and contains a condenser
heat exchange unit, indicated generally by reference numeral 94.
The condenser heat exchange unit 94 comprises a condenser coil 96
having a plurality of tubes, preferably U-tubes, for conducting
refrigerant received from the evaporator coil 86. A compressor 98
is interposed in the system and operates to pressurize the
refrigerant being returned to the evaporator coil 86. As shown best
in FIGS. 3 and 4 of the drawings, the condenser coil 96 is housed
within a condenser hood 100, the bottom of which constitutes a
motor board assembly 102 that includes a motor board in the form of
an elongated plate 104 that underlies and forms the bottom of the
condenser hood 100. The motor board plate 102 is desirably
inclinedly disposed and mounts a blower 106 that is suspended from
the plate 102 by means of a bolted connections 108 and whose outlet
communicates with the interior of the condenser hood 100 in order
to direct coolant air in heat exchange relation with respect to the
refrigerant fluid flowing in the tubes of the condenser coil
96.
[0031] As shown, the shroud 100 housing the condenser coil 96 is
disposed in an elevated position at the rear of the chassis 14
whereby the blower 106 is contained in a plenum 110 formed beneath
the condenser coil 96. A liquid collection pan 112 is disposed at a
somewhat elevated position in the plenum 110 and operates by means
of a transfer tube 113 to receive liquid which collects in the tray
92 for collecting condensate generated on the tubes 88 of the
evaporator coil 86.
[0032] From a consideration of FIG. 3 it will be appreciated that,
with the chassis 14 installed within the cabinet 12, its rear end,
that contains the condenser heat exchange unit 94 and underlying
chamber 110, is caused to abut the building outside wall 44. A
plate 114, which forms the back side of the chassis 14, contains
openings for the passage of air. The lower portion of the plate 114
contains opening 116 for the reception of fresh outside air which
is directed from wall opening 48 beneath the liquid collection
panel 112 through an opening 118 at the bottom end of the partition
plate 72 and into the evaporator section 68 of the chassis 14. Such
outside air is submitted to processing in the evaporation section
68 prior to discharge into the space to be ventilated. Another
opening 117 communicating with the wall opening 48 above the liquid
collection pan 112 is adapted to conduct fresh outside air into the
condenser section 70 for cooling refrigerant in the tubes of the
condenser coil 96.
[0033] According to this described arrangement, the cooling air is
induced by the action of the blower 106 to enter the plenum 110 and
to flow across the surface of the liquid in the collection pan 112
where it withdraws moisture which is blown in mixed relation with
the air into the chamber formed by the condenser shroud 100 to pass
in heat transfer relation with respect to the tubes of the
condenser coil 96 before exiting through opening 119 in the back
plate 114 of classis 14 and the air discharge opening defined by
the upper opening 46 in the building wall 44. It will be
appreciated that a more effective transfer of heat between
condenser refrigerant and cooling fluid is effected by the mixture
of moisture with inlet air passed to the condenser coil 96 in that
the evaporative effect of the moisture carried by the air is
utilized for extracting heat more effectively from the
refrigerant.
[0034] Process air to the ventilator 10 includes, besides the
aforementioned fresh inlet air, which enters the chassis 14 through
the lower air opening 116 and enters the evaporation section 68
through the opening 118 in the partition plate 72, also return air
from the ventilated space which passes through the return air grill
52 in the cabinet 12 and to the evaporator section 68 through
opening 120 in an inclined face of the chassis front wall 58. The
process air which enters the ventilator chassis 14 is filtered by
readily removable sheet filters including fresh air filter 122 and
return air filter 124.
[0035] A movable partition plate 126 is disposed between the
filters 122 and 124 and has as its principle function to assist in
the separation of the outside air flow path from the return air
flow path. The partition plate 126 is pivotally mounted on the
chassis base 24 by means of a pivot pin 128 which permits forward
pivoting of the plate when a wing grip 130 thereon is manually
grasped. Thus, folding of the partition plate 126 enables easy
access to the fresh air filter 122 along with access to the return
air filter 124 for filter repair or replacement upon removal of the
front panels on the cabinet 12 and chassis 14, respectively.
[0036] Control of flow of inlet air to the ventilator 10 is
provided by a roll damper 132 that is connected for pivotal
movement between vertical support plates shown at 134 in FIG. 5.
The roll damper 132 includes end brackets 126 (only one of which is
shown in the drawing figures) which are suspended by means of pivot
pins 138 from the respective support plates 134. A damper plate
140, shown to be of V- or chevron-shape is carried between the end
brackets 136 and extends substantially coextensively with the
combined length of the blowers 78. It will be appreciated, as best
indicated by FIG. 3 of the drawing, that with the roll damper 132
positioned as represented by the solid line figure, inlet flow of
process air to the ventilator 10 will be outside air which flows
through opening 48 in building wall 44, and thence through openings
116 and 118 in the chassis back plate 114 and partition plate 72,
respectively, to the inlet (not shown) of the blowers 78, whereby
the air is passed through openings 79 under pressure to the
evaporator section 68 for ultimate discharge into the space to be
ventilated through the discharge openings 67 and 40 in the roofs of
the chassis 14 and cabinet 12, identified by reference numerals 64
and 36, respectively.
[0037] Alternatively, with the roll damper 132 pivoted to the left,
as shown by the broken line representation in FIG. 3, total process
air flow to the ventilator 10 occurs via the return air openings 52
and 120 in the cabinet 12 and chassis 14, respectively, whereby air
flow, after passing through the openings and filter 124 is forced
by blowers 78 into the evaporator section 68 and thence from the
ventilator via the openings 36 and 37 as processed air to the
ventilator space.
[0038] With the roll damper 132 positioned as best shown in FIG. 5,
at a mid-point position between the openings 52 and 118, process
air delivered to the evaporator section 68 of the ventilator is a
combination of both fresh inlet air from the outside and return air
from the ventilated space which passes through grill 52 in the
cabinet 12 and the opening 66 in the chassis 14. The position of
the roll damper 132, which is effected by means of the operation of
a proportioning motor (not shown), determines the composition of
the process air admitted to the ventilator 10.
[0039] The modular unit ventilator 10 is typically installed in a
room or space to be ventilated with the back end of the cabinet 12,
that is essentially open, abutting an outside building wall 44, or
the like. With the front panel 16 of the cabinet removed, the
chassis 14 is installed in the cabinet 12, the chassis being
slidingly supported on support rails 28 between a pair of spaced
cabinet side plates 32. The detachable electric plug 18 is
connected to a jack on the chassis side wall 62 with the wire
thereof being connected to the control box 54 attached to the
adjacent cabinet side plate 32.
[0040] In ordinary operation in which air is to be treated by an
air conditioning process before being discharged into the space to
be cooled, a fluid refrigerant, such as the typical HCFC
refrigerant, R-22, is circulated continuously in an essentially
closed cycle through the tubes 88 of the evaporator coil 86, the
compressor 97 and the tubes of the condenser coil 96. As shown, a
gas by-pass valve 91 is provided in the refrigerant circuit in
order to prevent overload of the compressor 97 by bypassing excess
gaseous refrigerant to the condenser coil 97. Outside air to be
treated is admitted to the unit ventilator through opening 48 in
the building wall 44 whence it flows serially through the opening
116 in the chassis back plate 114, opening 118 in the partition 72,
entering the evaporator section 68 through filter 122 in the lower
region of the section before being conducted via blowers 78 through
the evaporator coil 80 to be cooled via evaporative cooling by the
refrigerant flowing through the evaporator tubes 88 and exiting the
unit ventilator through the openings 67 and 40 in the chassis 14
and cabinet 12.
[0041] It should be appreciated that, simultaneously with the flow
of outside air induced by blowers 78 through the evaporator section
68 of the unit, a flow of outside air is also induced by blower 106
in the lower region of the condenser section 70 whereby outside air
passes through the lower opening 48 in the building wall 44,
through the opening 120 in chassis back plate 114 to the blower 106
from whence the air flow is directed into the plenum 110 formed by
the condenser hood 100, being directed in heat transfer relation
with the condenser coil 96 to condense the refrigerant contained in
the condenser tubes before existing the chassis through openings
119 and 46 in the chassis back plate 114 and the building wall 44,
respectively.
[0042] According to the invention, evaporative cooling of the
condenser coil 96 contributes to a liquid drain-free construction
produced by the fact that condensate removed from the process air,
which forms on the outside surface of the evaporator tubes 88, is
conducted downwardly by gravity and is collected in the condensate
collection tray 92 which underlies the evaporator coil 86. This
condensate is conducted via transfer tube 113 to the liquid
collection pan 112 that divides the plenum 110 in the lower region
of the condenser section 70 of the unit. As the open upper side of
the collection pan 112 is exposed to the condenser cooling air flow
entering the chassis through the opening 117 in the chassis back
plate 114 the air mixes with moisture from the liquid in the pan
112 thereby providing additional cooling capability for the
condenser cooling air as well as evaporating the liquid effluent
from the treatment process whereby no liquid drain from the unit
ventilator is required.
[0043] The versatility of the present invention is manifest by the
fact that, in addition to the treatment of outside air,
recirculated return air from the ventilated space can also be
treated, either alone or in mixed relation with outside air
delivered to the unit. Thus, with the roll damper 132 disposed in
the position shown by broken lines return air from the ventilated
space is admitted to the unit for processing in the manner
previously described through the return air openings 66 in cabinet
12 and 120 in the chassis 14 and filter 124. A controlled mixture
of fresh outside air and return air can be admitted to unit by
merely adjusting the position of the roll damper 132 between the
illustrated left and right hand positions.
[0044] Further, the described unit ventilator 110 can, depending
upon ambient air temperatures, alternatively be operated, with the
evaporator and condenser rendered inoperative, by allowing fresh
air to be induced by the blowers 78 and blown as a forced air flow
into the ventilated space. Or the unit ventilator 110 can be used
as a room air heater by the provision of air heating apparatus
shown in FIG. 3 as an electrically operated heater 95 or a hydronic
heater 93.
[0045] As best shown in FIG. 6, the unit ventilator 10' of the
invention contemplates the use of multiple chassis 14' in a cabinet
12' of elongated length in order to accommodate reception of plural
chassis, typically two, which may have the same or different
capacities. As for example, where individual chassis having air
treatment capacities of 20,000 Btu, 24,000 Btu and 32,000 Btu,
respectively, are provided, it will be appreciated that, through
the provision of plural chassis in a cabinet, modular production of
unit ventilators having Btu capacities of 40,000, 44,000, 48,000,
52,000, 56,000 and 64,000 can be provided.
[0046] Furthermore, an additional benefit derived from the
production of unit ventilators 10' utilizing plural chassis within
a cabinet is that, in the event of a need to remove one chassis
from service, as for example for maintenance or repair purposes,
the unit ventilator is able to remain operative, albeit at a
reduced capacity level.
[0047] As a result of the hereindescribed invention there is
provided a modular unit ventilator of improved construction and
design whereby air ventilation for large spaces, such as school
rooms, or the like, is more effectively achieved through the use of
equipment which is characterized by reduced production and
operation costs.
[0048] While this invention has been described as having a
preferred design, the present invention can be further modified
within the spirit and scope of this disclosure. This application is
therefore intended to cover any variations, uses, or adaptations of
the invention using its general principles. Further, this
application is intended to cover such departures from the present
disclosure as come within known or customary practice in the art to
which this invention pertains and which fall within the limits of
the appended claims.
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