U.S. patent application number 14/728545 was filed with the patent office on 2015-12-10 for hvac roof curb retrofit.
The applicant listed for this patent is Enthaltec, Inc.. Invention is credited to Christopher P. Bloch.
Application Number | 20150354867 14/728545 |
Document ID | / |
Family ID | 54769302 |
Filed Date | 2015-12-10 |
United States Patent
Application |
20150354867 |
Kind Code |
A1 |
Bloch; Christopher P. |
December 10, 2015 |
HVAC ROOF CURB RETROFIT
Abstract
A ventilation adapter unit or roof curb retrofit is provided for
reducing energy costs in operating a building ventilation system.
The unit is disposed between a traditional HVAC unit and a surface
of the building, and has a plurality of internal passageways
including a return air passageway, a discharge air passageway, and
a supplemental discharge air passageway. Air entering the discharge
air passageway from the HVAC unit is selectively routed into the
supplemental discharge air passageway, where it is cooled by a
cooling panel according to the position of a damper in the
discharge air passageway. The cooling panel receives chilled fluid
from a chiller, such as an ice storage system that operates a
refrigeration unit during off-peak hours. Regardless of whether the
air is routed through or around the damper, the air is then
discharged from the retrofit unit and into the building.
Inventors: |
Bloch; Christopher P.;
(Grand Rapids, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Enthaltec, Inc. |
Dutton |
MI |
US |
|
|
Family ID: |
54769302 |
Appl. No.: |
14/728545 |
Filed: |
June 2, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62008775 |
Jun 6, 2014 |
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Current U.S.
Class: |
62/333 ; 454/233;
454/242; 62/406 |
Current CPC
Class: |
F24F 7/08 20130101 |
International
Class: |
F25B 25/00 20060101
F25B025/00; F25D 17/08 20060101 F25D017/08; F24F 7/08 20060101
F24F007/08 |
Claims
1. A ventilation adapter unit for a building ventilation system,
said adapter unit comprising: a main housing defining an inner
chamber, said main housing including first and second end portions,
said first end portion configured to engage an exterior building
surface associated with the building ventilation system, and said
second end portion configured to engage a powered ventilation unit
of the building ventilation system; a plurality of interior walls
dividing said inner chamber into a plurality of passageways
including (i) a return air passageway open at both said first and
second end portions of said main housing, (ii) a discharge air
passageway open at both said first and second end portions of said
main housing, and (iii) a supplemental discharge air passageway
having an inlet portion in fluid communication with said discharge
air passageway near said open second end portion of said main
housing and an outlet portion in fluid communication with said
discharge air passageway near said open first end portion of said
main housing; a heat exchanger disposed in said supplemental
discharge air passageway; and a damper disposed in said discharge
air passageway between said first and second end portions of said
main housing and positionable between an open position and a closed
position; wherein when said damper is in the open position, a flow
of discharge air is permitted to pass from the powered ventilation
unit through said second end portion of said main housing and
substantially directly out through said first end portion of said
main housing, and when said damper is in the closed position, the
flow of discharge air is directed into said supplemental air
passageway, through said heat exchanger, and out through said first
end portion of said main housing.
2. The ventilation adapter unit of claim 1, wherein said damper is
oriented along a diagonal with a first end portion located
proximate said first end portion of said main housing and a second
end portion located proximate said second end portion of said main
housing.
3. The ventilation adapter unit of claim 2, wherein said plurality
of interior walls comprises a first interior wall positioned
between said damper and said inlet portion of said supplemental
discharge air passageway, and wherein said first interior wall
defines a generally triangular opening at said inlet portion of
said supplemental discharge air passageway.
4. The ventilation adapter unit of claim 1, wherein said heat
exchanger comprises a cooling panel in fluid communication with a
chiller.
5. The ventilation adapter unit of claim 4, further in combination
with the chiller, wherein said chiller comprises an ice storage
unit.
6. The ventilation adapter unit of claim 4, further comprising a
controller, wherein said controller is operable to selectively
actuate said damper to the closed position and to activate the
chiller to thereby circulate chilled fluid through said cooling
panel.
7. The ventilation adapter unit of claim 6, wherein said controller
is operable in response to at least one chosen from (i) a
thermostat located in a room of the building, (ii) a real time
clock, and (iii) a chiller status signal.
8. The ventilation adapter unit of claim 7, wherein said controller
is further operable to selectively energize a blower and an air
conditioner of the powered ventilation unit.
9. The ventilation adapter unit of claim 8, wherein said controller
is operable to simultaneously (i) energize the blower of the
powered rooftop ventilation unit, (ii) de-energize the air
conditioner of the powered rooftop ventilation unit, (iii) actuate
said damper to the closed position, and (iv) activate said
chiller.
10. A roof curb retrofit unit comprising: a main housing comprising
perimeter walls that cooperate to define an inner chamber, a lower
portion for engaging a roof curb, and an upper portion for engaging
a powered rooftop ventilation unit; a plurality of interior walls
dividing said inner chamber into a plurality of passageways
including (i) a return air passageway open at both said upper and
lower portions of said main housing, (ii) a discharge air
passageway open at both said upper and lower portions of said main
housing, and (iii) a supplemental discharge air passageway having
an inlet portion in fluid communication with said discharge air
passageway near said open upper portion of said main housing and an
outlet portion in fluid communication with said discharge air
passageway near said open lower portion of said main housing; a
cooling panel disposed in said supplemental discharge air
passageway between said inlet and outlet portions thereof, said
cooling panel configured to permit a flow of air therethrough and
to remove heat from the air; and a damper disposed in said
discharge air passageway between said upper and lower portions of
said main housing, wherein said damper is configurable between an
open position and a closed position; wherein when said damper is in
the open position, a flow of discharge air is permitted to pass
from the rooftop ventilation unit through said upper portion of
said main housing and substantially directly out through said lower
portion of said main housing, and when said damper is in the closed
position, the flow of discharge air is directed into said
supplemental air passageway, through said cooling panel, and out
through said lower portion of said main housing.
11. The roof curb retrofit unit of claim 10, wherein said main
housing comprises a bottom panel attached to said perimeter walls,
said bottom panel defining openings only at said return air
passageway and at said discharge air passageway.
12. The roof curb retrofit unit of claim 11, wherein said damper is
oriented along a diagonal relative to a horizontal plane, and
comprises an upper end portion proximate said upper portion of said
main housing and a lower end portion proximate said lower portion
of said main housing.
13. The roof curb retrofit unit of claim 10, wherein said plurality
of interior walls comprise a first interior wall positioned between
said damper and said inlet portion of said supplemental discharge
air passageway, and wherein said first interior wall defines a
generally triangular opening at said inlet portion of said
supplemental discharge air passageway.
14. The roof curb retrofit unit of claim 10, wherein an entirety of
the flow of discharge air entering said discharge air passageway
passes through said damper or said cooling panel.
15. The roof curb retrofit unit of claim 10, wherein said cooling
panel is in fluid communication with a chiller.
16. The roof curb retrofit unit of claim 15, further comprising a
controller, wherein said controller is operable to selectively
actuate said damper to the closed position and to activate the
chiller to thereby circulate chilled fluid through said cooling
panel.
17. The roof curb retrofit unit of claim 16, wherein said
controller is operable in response to at least one chosen from (i)
a thermostat located in a room of a building on which said roof
curb retrofit unit is mounted, (ii) a real time clock, (iii) a
chiller status signal.
18. The roof curb retrofit unit of claim 17, wherein said
controller is further operable to selectively energize a blower and
an air conditioner of the powered rooftop ventilation unit.
19. The roof curb retrofit unit of claim 18, wherein said
controller is operable to simultaneously (i) energize the blower of
the powered rooftop ventilation unit, (ii) de-energize the air
conditioner of the powered rooftop ventilation unit, (iii) actuate
said damper to the closed position, and (iv) activate said
chiller.
20. A method of operating a roof curb retrofit unit, said method
comprising: directing return air from a building interior to a
return air passageway of the roof curb retrofit unit; directing the
return air from the return air passageway to a powered rooftop
ventilation unit coupled to the roof curb retrofit unit; passing
the return air through a blower of the powered rooftop ventilation
unit to convert the return air to discharge air; directing the
discharge air from the powered rooftop ventilation unit to a
discharge air passageway of the roof curb retrofit unit; closing a
damper that is disposed in the discharge air passageway to thereby
direct the discharge air (i) into an inlet portion of a
supplemental discharge air passageway of the roof curb retrofit
unit that is in fluid communication with the discharge air
passageway, (ii) through a cooling panel disposed in the
supplemental discharge air passageway, and (iii) out of the roof
curb retrofit unit through an outlet portion of the discharge air
passageway; opening the damper to thereby direct the discharge air
through the damper and directly to the outlet portion of the
discharge air passageway so that the discharge air substantially
bypasses the supplemental discharge air passageway; and circulating
a cooling fluid through the cooling panel when the damper is
closed.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of U.S.
provisional application Ser. No. 62/008,775, filed Jun. 6, 2014,
which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to ventilation
systems for buildings, and more particularly, to adapters or
retrofit units for mounting a powered HVAC unit along a building
exterior.
BACKGROUND OF THE INVENTION
[0003] Heating, ventilation, and air conditioning ("HVAC") units
are typically mounted to building rooftops, or other building
exterior surfaces, at a flashed-in "curb" that is made up of a
plurality of upraised walls surrounding an opening in the building
exterior. Such HVAC units typically include at least a
refrigerant-based air conditioning system including a compressor,
an evaporator, a condenser, an electric blower, and associated
ductwork contained within a main housing, with the unit made
weather-resistant for outdoor installations. Optionally, HVAC units
may further include a heater, such as electric coils or a gas-fired
burner, and may be operable in a fan-only mode for ventilation
purposes.
[0004] In some cases, and especially when a newer HVAC unit is to
be installed at an existing roof curb, a roof curb adapter is
placed between the HVAC unit and the roof curb to obviate the need
for modifying or re-sealing the roof curb, and also to obviate the
need to locate or custom build an HVAC unit having inlets and
outlets that dimensionally match the outlets and inlets of an
existing roof curb and associated building ductwork.
[0005] Electrical rates typically fluctuate according to the time
of day and even the day of the week due to changes in demand. For
example, utility companies must provide enough electrical
generating capacity to meet customer demand during peak consumption
times of the day, such as hot summer afternoons. However, energy
demands are substantially less during cooler nighttime hours, so
that substantial excess capacity is available during those hours,
and energy pricing can be reduced substantially during those times.
To take advantage of the lower cost energy available during "off
hours," ice storage systems have been developed to create ice or
other cooled substances during off hours by operating refrigeration
systems associated with the ice storage systems. The formed ice or
other chilled material is stored in insulated containers, so that a
separate cooling fluid may be circulated through the ice or other
chilled substance during peak daytime hours, and then through a
heat exchanger in a discharge air duct that supplies air to a
building, to thereby cool the building during times when energy
cost can be substantially higher. Thus, the cooling capacity of the
ice or other chilled substance may be utilized for cooling the
building air during peak hours, while reducing or eliminating the
need to operate costly energy-consuming air conditioning systems,
and especially their refrigerant compressors, during peak
hours.
SUMMARY OF THE INVENTION
[0006] The present invention provides a modified roof curb adapter
or retrofit unit, which permits the substantially conventional use
of a rooftop HVAC unit, and which also permits the use of a
separate chiller, such as an ice storage unit, to take advantage of
lower electricity costs during off-peak hours. The retrofit unit
includes a conventional return air passageway that directs warm or
stale air from the building into the HVAC unit, but the retrofit
unit has a damper or valve disposed along a discharge air
passageway so that air received into the HVAC unit can be
selectively directed through a supplemental discharge air
passageway in the retrofit unit, the supplemental discharge air
passageway containing a heat exchanger, such as a cooling panel
associated with a chiller.
[0007] This arrangement permits the HVAC unit to be operated in a
fan-only mode, without energizing a refrigerant compressor of an
air conditioning system in the HVAC unit, and to instead cool the
air using the cooling panel associated with the chiller, before the
discharge air is passed back into the building. However, when the
damper or valve is open, the air exiting the HVAC unit is routed
directly through the damper or valve and out through the retrofit
unit and into the building, substantially bypassing the cooling
panel associated with the chiller. By essentially removing the
cooling panel from the air stream when the damper or valve is open,
the fan efficiency of the HVAC unit is substantially unaffected by
the presence of the cooling panel in the retrofit unit, because the
air discharged from the HVAC unit is not being routed through the
cooling panel that otherwise causes a pressure drop in the
airstream and would require higher fan power to maintain a given
airflow rate. Accordingly, the HVAC unit may be operated in a
conventional manner as desired, and may be operated in a fan-only
mode in which air is not being cooled by the HVAC unit, but instead
the air is routed along the supplemental discharge air passageway
in the retrofit unit, where it passes through the cooling panel
associated with the chiller, so that energy consumed by the chiller
during off-peak hours may be used during on-peak hours to provide
cooled air to the building during on-peak hours, as desired.
[0008] According to an aspect of the present invention, a
ventilation adapter or curb retrofit unit is provided for a
building ventilation system, the adapter unit including a main
housing, a plurality of interior walls, a heat exchanger, and a
damper. The main housing defines an inner chamber and has first and
second end portions, the first end portion for engaging an exterior
building surface that is associated with the building ventilation
system, and the second end portion for engaging or receiving a
powered ventilation unit associated with the building ventilation
system. The interior walls divide the inner chamber of the main
housing into a plurality of air passageways including a return air
passageway that is open at both the first and second end portions
of the main housing, a discharge air passageway that is open at the
first and second end portions of the main housing, and a
supplemental discharge air passageway having an inlet portion in
fluid communication with the discharge air passageway near the open
second end portion of the main housing, and an outlet portion in
fluid communication with the discharge air passageway near the open
first end portion of the main housing. The heat exchanger is
positioned in the supplemental discharge air passageway, and is
operable to add or remove heat from the flow of air passing
therethrough. The damper is positioned in the discharge air
passageway, between the first and second end portions of the main
housing, and is positionable between an open position and a closed
position. When the damper is in the open position, a flow of
discharge air is permitted to pass from the powered ventilation
unit through the second end portion of the main housing, and
substantially directly out through the first end portion of the
main housing. When the damper is in the closed position, the flow
of discharge air is directed into the supplemental air passageway,
through the heat exchanger, and out through the first end portion
of the main housing.
[0009] Optionally, the first end portion of the housing is a lower
end that engages a roof curb at the top of the building, and the
second end portion of the main housing is an upper end that
receives the powered ventilation unit.
[0010] Optionally, the damper includes one or more pivotable
louvers and a powered actuator that pivots the louvers in response
to a damper activation signal. The damper may be oriented along a
diagonal (i.e. neither perpendicular nor parallel to outer walls of
the retrofit unit), with a first end portion located proximate the
first end portion of the main housing, and a second end portion
located proximate the second end portion of the main housing.
[0011] Optionally, the interior walls include a first wall that is
positioned between the damper and the inlet portion of the
supplemental discharge air passageway, the first interior wall
defining a generally triangular opening at the inlet portion of the
supplemental discharge air passageway.
[0012] Optionally, the heat exchanger is a cooling panel having
fluid conduit that is in fluid communication with a chiller, such
as an ice storage unit associated with the building and operable
during off-peak hours to create ice or other chilled material or
substance, which can later be used to cool a fluid that is directed
through the cooling panel at times when air cooling is desired,
particularly during on-peak hours of higher energy costs.
[0013] Optionally, a controller is used to selectively actuate the
damper to its closed position, and to activate the chiller to
circulate chilled fluid through the cooling panel as air passes
through the supplemental discharge air passageway and the cooling
panel. The controller may be operable in response to one or more of
a thermostat located in a room of the building, a real time clock,
and a chiller status signal. The controller may further be operable
to selectively energize the blower and compressor-based air
conditioner of the powered ventilation unit. The controller may
further be operable to simultaneously energize the blower of the
powered roof top ventilation unit, de-energize the air conditioner
of the powered rooftop unit, actuate the damper to the closed
position, and activate the chiller.
[0014] Thus, the ventilation adapter unit or roof curb retrofit
unit of the present invention facilitates the use of lower-priced
energy during off-peak periods, and lowering energy consumption
during on-peak periods, but without significantly increasing the
energy consumption of a blower fan associate with a conventional
HVAC unit, since a cooling panel or heat exchanger associated with
the retrofit unit is essentially removed from the airstream during
periods when it is not in use. The retrofit thus facilitates the
installation of new HVAC units along a building exterior, without
substantially affecting the operating efficiency of the HVAC unit,
and by facilitating reduced usage of the HVAC unit during periods
of peak energy rates or prices, by cooling discharge air using a
chiller that primarily consumes energy during off-peak hours while
deactivating or limiting the use of a compressor-based air
conditioner associated with the HVAC unit.
[0015] These and other objects, advantages, purposes and features
of the present invention will become apparent upon review of the
following specification in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a simplified diagrammatic view of an HVAC system
for a building, including a roof curb retrofit unit in accordance
with the present invention;
[0017] FIGS. 2-5 are a series of top perspective views of the roof
curb retrofit unit of FIG. 1, taken from different viewing angles;
and
[0018] FIG. 6 is a top plan view of the roof curb retrofit
unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Referring now to the drawings and illustrative embodiments
depicted therein, a ventilation adapter unit in the form of a roof
curb retrofit unit 10 is configured for mounting atop a building
12, between a roof curb 14 and an HVAC unit 16 (FIG. 1), although
non-rooftop mounting locations are equally possible. Retrofit unit
10 has a main housing 18 with a first or lower end portion 18a that
rests atop roof curb 14, and a second or upper end portion 18b that
supports HVAC unit 16. Main housing 18 defines an inner chamber or
region, which is divided into a plurality of passageways by
interior divider walls. The passageways defined by main housing 18
include a return air passageway 20, a discharge air passageway 22,
and a supplemental discharge air passageway 24 (FIGS. 1 and 3-6).
Discharge passageway 22 contains a damper or valve 26 that is
operable to selectively direct discharge air received from HVAC
unit 16 into supplemental discharge air passageway 24, which
contains a heat exchanger in the form of a cooling panel 28, as
will be described in more detail below.
[0020] Main housing 18 has exterior surfaces made up of a plurality
of panels, typically of sheet metal, including a first end wall
30a, a second end wall 30b, a first sidewall 32a, a second sidewall
32b, and a generally L-shaped bottom wall 34 at lower end portion
18a along supplemental discharge air passageway 24 (FIGS. 3-6).
Optionally, a generally L-shaped top wall, corresponding to bottom
wall 34, can be positioned at upper end portion 18b of the main
housing, to enclose the supplemental discharge air passageway 24. A
first interior divider wall 36 is positioned between discharge air
passageway 22 and an intake end portion of supplemental discharge
air passageway 24, and a second interior divider wall 38 is
positioned on the opposite side of discharge air passageway 22 from
first wall 36, and separates return air passageway 20 from
discharge air passageway 22. First and second divider walls 26, 38
are generally parallel to first and second end walls 30a, 30b.
[0021] A third interior divider wall 40 is generally parallel to
first and second sidewalls 32a, 32b, with first and second interior
divider walls 36, 38 terminating at third interior divider wall 40
(FIGS. 3-6). In the illustrated embodiment, first and second
divider walls 36, 38 extend inwardly from first sidewall 32a, with
first interior divider wall 36 having an extension portion 36a
projecting further toward second sidewall 32b to accommodate
cooling panel 28. However, it will be appreciated that the size and
placement of cooling panel 28, and of the various sidewalls in the
main housing, may be changed as desired for a particular
application, without departing from the spirit and scope of the
present invention.
[0022] Third interior divider wall 40 defines an opening 42 between
first and second interior divider walls 36, 38, and below an upper
end portion 26a of damper 26 (FIGS. 3 and 4). Damper 26 is set at a
diagonal angle, so that its upper end portion 26a is positioned
along interior divider wall 40, while a lower end portion 26b is
positioned along first sidewall 32a at L-shaped bottom wall 34. As
will be described in more detail below, when damper 26 is open,
such as shown in FIGS. 2-6, discharge air entering discharge air
passageway 22 at upper end portion 18a will pass substantially
uninhibited through damper 26 and out through a discharge opening
44 formed in lower end portion 18a, between first and second
divider walls 36, 38. When damper 26 is closed, discharge air is
routed through a generally triangular opening 46 and into
supplemental discharge air passageway 24, where it passes through
cooling panel 28, whereupon it is directed out through discharge
opening 44 via opening 42 formed in third interior divider wall 40.
Thus, when damper 26 is closed, discharge air in the discharge air
passageway 22 is forced around damper 26 and through cooling panel
28, rather than directly through damper 26, although it will be
appreciated that the discharge air eventually exits through the
same discharge opening 44 regardless of the position of damper
26.
[0023] Referring again to FIG. 1, return air passageway 20 receives
warm or stale air from building 12 via a return air duct 48 having
an inlet 48a inside the building, and having an outlet 48b in the
roof curb 14. Similarly, all discharge air entering discharge air
passageway 22 exits through discharge opening 44 and into a
discharge air duct 50 having an inlet portion 50a at roof curb 14,
and an air outlet portion 50b in a room of building 12. Return air
exiting return air passageway 20 at upper end portion 18a of the
main housing passes into an intake duct 52, passes through a heat
exchanger such as an evaporator 54 that receives refrigerant from a
compressor 56. A condenser would also be included, and a fresh air
intake and/or heater are optional, but are omitted from the drawing
for clarity. It will further be appreciated that, instead of a
refrigerant-based cooling system, the HVAC unit could utilize an
evaporative cooling system, a piezoelectric cooling system, or
substantially any other type of heat exchanger, without departing
from the spirit and scope of the present invention.
[0024] After passing through evaporator 54, which may or may not be
actively operating to cool the air received through intake duct 52,
the air enters a discharge duct 58 containing a blower fan 60,
which draws the air through return air duct 48, intake duct 52,
discharge duct 58, and directs the discharge air into discharge air
passageway 22 of retrofit unit 10 and, subsequently, into discharge
air duct 50 and into the room of the building. It is desirable that
blower fan 60 is operable independently of compressor 56 so that
HVAC unit 16 may be operated in a relatively low-energy state by
running only blower fan 60 for ventilation and subsequent cooling
by the cooling panel 28 of retrofit unit 10. This permits discharge
air to be cooled only by cooling panel 28 when damper 26 is
closed.
[0025] Cooling panel 28 is another heat exchanger that receives
chilled fluid via a cold fluid inlet line 62a, which originates at
a chiller such as an ice storage unit 64 located in or nearby
building 12. Typically, the chilled fluid passes through coils or a
series of fluid passageways of cooling panel 28, absorbing heat
from the airstream as the air passes through supplemental discharge
passageway 24. The fluid then exits through a fluid outlet line
62a, which leads back to ice storage unit 64 for re-cooling and
recirculation back to cooling panel 28.
[0026] A controller 66 is operable to control HVAC unit 16, damper
26, and ice storage unit 64. Controller 66 is in communication with
HVAC unit 16 via an HVAC control line 68, is in communication with
a powered actuator associated with damper 26 via a damper control
line 70, and is in communication with ice storage unit 64 via a
chiller control line 72. Preferably, controller 66 is operable to
independently energize and de-energize compressor 56 and blower fan
60 of HVAC unit 16, reposition damper 26 in the open or closed
position as needed, and to activate ice storage unit 64 by
operating a fluid pump to direct chilled fluid into cooling panel
28 via cold fluid inlet line 62a. In addition, controller 66 may
include or be in communication with a real time clock, and with a
thermostat 74 positioned in a room of the building. Optionally, the
controller may be in wireless communication with the various
components that it controls and/or from which it receives data that
is uses to determine the appropriate operating configuration.
[0027] To operate HVAC unit 16, retrofit unit 10, and ice storage
unit 64 in a cost-efficient and optimized manner, controller 66 is
programmed to operate ice storage unit 64 during off-peak hours
when energy costs are lower, such as at night, and during that time
controller 66 may rely on compressor 56 and evaporator 54 of HVAC
unit 16 to provide the necessary cooling of discharge air through
discharge air passageway 22, with damper 26 open. Optionally,
cooling may also be supplemented by cooling panel 28 during
off-peak hours, if desired and if cooling capacity remains in ice
storage unit 64. During periods of high energy costs, such as
during summer daytime hours, controller 66 is programmable to
operate ice storage unit 64 to pump chilled fluid through cooling
panel 28, and to operate blower fan 60 without operating compressor
56, with damper 26 actuated to a closed position to direct the
discharged air through supplemental discharge air passageway 24 and
cooling panel 28, thereby utilizing the cooling capacity of ice
storage unit 64 during periods of peak energy costs. Controller 66
may receive a status signal from ice storage unit 64, the status
signal being indicative of the remaining cooling capacity of ice
storage unit 64, so that controller 66 can revert to normal
operation of HVAC unit 16 by operating compressor 56 and opening
damper 26 to bypass cooling panel 28 when the cooling capacity of
ice storage unit 64 has been depleted. It is envisioned that if ice
storage unit 64 retains cooling capacity after the conclusion of a
high cost energy time of day, controller 66 may continue to
circulate fluid from ice storage unit 64 through cooling panel 28
until its cooling capacity has been depleted. By programming
controller 66 with the times of day at which energy costs are
highest and lowest, controller 66 will operate retrofit unit 10,
HVAC unit 16, and ice storage unit 64 in a manner that minimizes
the cost of energy utilized in cooling interior rooms of building
12.
[0028] Although the ventilation adapter or retrofit unit of the
present invention is primarily described herein as a rooftop unit
that operates in a coordinated manner with a powered rooftop
ventilation system or unit, it will be appreciated that the
ventilation adapter or retrofit unit may be installed along
substantially any exterior wall or surface of a building, such as
for use with a wall-mounted ventilation system. The ventilation
adapter or retrofit unit may also be adapted for use in a building
interior. It will further be appreciated that the ventilation
adapter or retrofit unit can be readily adapted to supplement a
building's heating instead of (or in addition to) the building's
cooling, in substantially the same manner as described above, such
as by circulating warm fluid through the retrofit unit's heat
exchanger panel. In such an arrangement, the warm fluid may be
created by solar heating or with electricity or other energy source
during times of lower energy cost, and circulated through the heat
exchanger panel during times of higher energy cost.
[0029] Therefore, the present invention provides a ventilation
adapter unit or roof curb retrofit that minimizes the consumption
of high cost electrical energy during peak usage times of day, by
offsetting some of that energy usage with increased energy usage
during lower cost times of day. An ice storage system or the like
is operated during low cost periods, so that chilled fluid may be
circulated through a cooling panel in the retrofit unit during high
energy costs times, but substantially without increasing the energy
required to force discharge air through the cooling panel during
times when it is not in use. The retrofit unit is operable in
coordinated manner with the HVAC unit and with the ice storage
system, substantially automatically, to minimize energy costs for a
particular installation.
[0030] Changes and modifications in the specifically-described
embodiments may be carried out without departing from the
principles of the present invention, which is intended to be
limited only by the scope of the appended claims as interpreted
according to the principles of patent law including the doctrine of
equivalents.
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