U.S. patent application number 12/021216 was filed with the patent office on 2008-08-28 for rooftop modular fan coil unit.
Invention is credited to Cliff S. Chamberlain.
Application Number | 20080203866 12/021216 |
Document ID | / |
Family ID | 39715069 |
Filed Date | 2008-08-28 |
United States Patent
Application |
20080203866 |
Kind Code |
A1 |
Chamberlain; Cliff S. |
August 28, 2008 |
ROOFTOP MODULAR FAN COIL UNIT
Abstract
A rooftop cooling and/or heating unit may include, but is not
limited to, a supply fan and a heating and/or coiling device. The
cooling device is preferably one or more chilled water coils
suitably mounted within the unit in-line with fresh air delivered
via an air intake hood and/or return air supplied from the return
air duct. The unit further includes one or more fluid circulation
pumps connected in-line with the one or more chilled water coils.
Embodiments of the rooftop cooling and/or heating units may further
include one or more of the following: pump compartment, controls
compartment, power compartment, space for optional features,
varying air filter options, mixed air dampers, optional
exhaust/relief features, etc. The unit may receive part or all of
its power requirements from an associated solar power
generator.
Inventors: |
Chamberlain; Cliff S.;
(Kirkland, WA) |
Correspondence
Address: |
CHRISTENSEN, O'CONNOR, JOHNSON, KINDNESS, PLLC
1420 FIFTH AVENUE, SUITE 2800
SEATTLE
WA
98101-2347
US
|
Family ID: |
39715069 |
Appl. No.: |
12/021216 |
Filed: |
January 28, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60886876 |
Jan 26, 2007 |
|
|
|
Current U.S.
Class: |
312/236 |
Current CPC
Class: |
F24F 1/0007 20130101;
F24F 1/0022 20130101; F24F 1/0035 20190201; F24F 2221/16
20130101 |
Class at
Publication: |
312/236 |
International
Class: |
F24F 5/00 20060101
F24F005/00 |
Claims
1. A rooftop modular fan coil unit, comprising: a cabinet defining
an interior cavity, an air intake, an air return inlet, and an air
supply outlet, wherein the air intake, the air return inlet, and
the air supply outlet are disposed in communication with the
cavity; a cooling unit mounted within the cabinet; supply and
return piping fluidly connected to the cooling unit; a cooling unit
connector assembly mounted on the cabinet and fluidly connected to
the supply and return piping; a monoflow pump fluidly connected
between the cooling unit and the cooling unit connector assembly;
and an air supply fan for moving air across the cooling unit and
out through the air supply outlet.
2. The unit of claim 1, further comprising a power connector
mounted on the cabinet.
3. The unit of claim 2, wherein the power connector is electrically
connected to the pump and the fan.
4. The unit of claim 1, further comprising space within the cabinet
for housing at least one device selected from a group of devices
consisting of batteries, power components, and control
components.
5. The unit of claim 1, further comprising a heating unit mounted
within the cabinet.
6. The unit of claim 5, wherein the heating unit is selecting from
a group consisting of a hot water coil, a heat reclaim coil, and an
electric heating coil.
7. The unit of claim 5, further comprising supply and return piping
fluidly connected to the heating unit and a heating device
connector assembly mounted on the cabinet.
8. The unit of claim 1, further comprising at least one device
selected from a group of devices consisting of dampers, reclaim
devices, UV purification lights, and filters.
9. The unit of claim 1, further comprising a control
communicatively connected to the pump and/or the fan.
10. The unit of claim 1, further comprising a solar power connector
mounted on the cabinet for connecting to an associated solar power
generator.
11. A rooftop modular fan coil unit, comprising: a cabinet defining
an interior cavity, an air intake, an air return inlet, and an air
supply outlet, wherein the air intake, the air return inlet, and
the air supply outlet being disposed in communication with the
cavity; a cooling unit mounted within the cabinet; supply and
return piping fluidly connected to the cooling unit; a cooling unit
connector assembly mounted on the cabinet and fluidly connected to
the supply and return piping; a monoflow pump fluidly connected
between the cooling unit and the cooling unit connector assembly;
an air supply fan for moving air across the cooling unit and out
through the air supply outlet; an electrical assembly electrically
connecting a motor of the air supply fan and the pump to an
electrical connector mounted on the cabinet; and a solar power unit
positioned external the cabinet and electrically connected to the
electrical connector.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/886,876, filed Jan. 26, 2007, the disclosure of
which is hereby incorporated by reference.
BACKGROUND
[0002] HVAC is an acronym that stands for "heating, ventilating,
and air conditioning." HVAC is sometimes referred to as "climate
control" and is particularly important in the design of residential
buildings, industrial buildings, and office buildings, where
humidity and temperature must all be closely regulated whilst
maintaining safe and healthy conditions within.
[0003] Heating, ventilating, and air conditioning is based on the
basic principles of thermodynamics, fluid mechanics, and heat
transfer. The three functions of heating, ventilating, and
air-conditioning are closely interrelated. All seek to provide
thermal comfort, acceptable indoor air quality, and reasonable
installation, operation, and maintenance costs.
[0004] These functions are typically integrated into one or more
HVAC systems in modern buildings. One type of HVAC system is the
fan coil unit (FCU). A FCU is a small terminal unit that is often
composed of only a blower and a heating and/or cooling coil, and is
often used in individual residential units such as single family
housing, condominium, hotel, etc. Another type of HVAC system is a
standard package rooftop unit (RTU). An RTU is an air-handling
unit, defined as either "recirculating" or "once-through" design,
made specifically for outdoor "rooftop" installation. RTU's are
popular for small commercial buildings, particularly of the single
story type. Conventional RTUs consist of the following components
within a pre-engineered package: a cabinet containing a supply fan,
mixed air dampers, a direct expansion (DX) refrigerant cooling
coil, piping connections to a refrigeration compressor, an
air-cooled condenser piped to the refrigeration compressor, one or
more temperature control components, and one or a plurality of
heating source options (e.g., hot water coil, heat reclaim coil,
electric heating coil, etc.).
[0005] While FCU's, RTU's, etc. are suitable for many existing
applications, they are not without limitations. To that end, the
HVAC industry is continually looking for improvements in HVAC
systems. As will be described in the Detailed Description below,
embodiments of the present invention are direction to HVAC systems
with such improvements.
SUMMARY
[0006] This summary is provided to introduce a selection of
concepts in a simplified form that are further described below in
the Detailed Description. This summary is not intended to identify
key features of the claimed subject matter, nor is it intended to
be used as an aid in determining the scope of the claimed subject
matter.
[0007] In accordance with aspects of the present invention, a
rooftop modular fan coil unit is provided. The unit includes a
cabinet defining an interior cavity, an air intake, an air return
inlet, and an air supply outlet, wherein the air intake, the air
return inlet, and the air supply outlet are disposed in
communication with the cavity. The unit also includes a cooling
unit mounted within the cabinet, supply and return piping fluidly
connected to the cooling unit, a cooling unit connector assembly
mounted on the cabinet and fluidly connected to the supply and
return piping, and a monoflow pump fluidly connected between the
cooling unit and the cooling unit connector assembly. The unit
further includes an air supply fan for moving air across the
cooling unit and out through the air supply outlet.
[0008] In accordance with another aspect of the present invention,
a rooftop modular fan coil unit is provided. The unit includes a
cabinet defining an interior cavity, an air intake, an air return
inlet, and an air supply outlet, wherein the air intake, the air
return inlet, and the air supply outlet are disposed in
communication with the cavity. The unit also includes a cooling
unit mounted within the cabinet, supply and return piping fluidly
connected to the cooling unit, a cooling unit connector assembly
mounted on the cabinet and fluidly connected to the supply and
return piping, and a monoflow pump fluidly connected between the
cooling unit and the cooling unit connector assembly. The unit
further includes an air supply fan for moving air across the
cooling unit and out through the air supply outlet, an electrical
assembly electrically connecting a motor of the air supply fan and
the pump to an electrical connector mounted on the cabinet, and a
solar power unit positioned external the cabinet and electrically
connected to the electrical connector.
DESCRIPTION OF THE DRAWINGS
[0009] The foregoing aspects and many of the attendant advantages
of this invention will become more readily appreciated by reference
to the following detailed description, when taken in conjunction
with the accompanying drawings, wherein:
[0010] FIG. 1 is a perspective view of one exemplary embodiment of
an RMFCU constructed in accordance with aspects of the present
invention, wherein the RMFCU is mounted to a roof curb;
[0011] FIG. 2 is a side interior view of the RMFCU of FIG. 1
mounted on a roof via a roof curb;
[0012] FIG. 3 is a top interior view of the RMFCU of FIG. 1;
[0013] FIG. 4 is a schematic diagram of one exemplary embodiment of
an RMFCU;
[0014] FIG. 5A is a standard roof curb showing typical
supply/return duct connections;
[0015] FIG. 5B is a special high return air roof curb showing
typical supply/return duct connections.
DETAILED DESCRIPTION
[0016] Embodiments of the present invention are directed to cooling
and/or heating units suitable for use in the heating, ventilation
and air-conditioning (HVAC) industry. In particular, embodiments of
the present invention are directed to integrated cooling and/or
heating units that are typically known in the industry as
pre-engineered package HVAC units. Generally described, such
package units may be pre-engineered, pre-wired, and include factory
piping and optional factory controls so that with connection to the
required utilities it is ready to perform as intended per cataloged
performance characteristics.
[0017] As will be described in more detail below, embodiments of
the cooling and/or heating units are suitable for use in rooftop
installations for light industrial, commercial and some unique
residential applications. Embodiments of the rooftop cooling and/or
heating units may include, but are not limited to, a supply fan and
a heating and/or coiling device. Embodiments of the rooftop cooling
and/or heating units may further include one or more of the
following: pump compartment, controls compartment, power
compartment, space for optional features, varying air filter
options, mixed air dampers, optional exhaust/relief features,
etc.
[0018] The cooling and/or heating units will be referred to herein
as a rooftop modular fan coil unit (RMFCU). It will be appreciated
that some embodiments of the RMFCU may include fewer components
than described above, or in different combinations. Each RMFCU is
intended to replace, or be used in-lieu of, a standard package
rooftop unit (RTU) or larger semi-custom variable air volume
package unit in some embodiments.
[0019] Turning now to FIG. 1, there is shown an exemplary
embodiment of an RMFCU, generally designated 10, constructed in
accordance with aspects of the present invention. The purpose of
RMFCU 10 is to heat and/or cool the air drawn from a conditioned
space by a return air duct (not shown) and/or fresh air drawn in
from outside the RMFCU. The conditioned space may be the interior
of the building itself, a group of rooms or only one room. The size
and capacity of the RMFCU 10 is dependent on heating or cooling
loads of the conditioned space. The RMFCU 10 may be designed for
both heating and cooling the air to be conditioned, or the RMFCU
may only be designed for cooling while others may only be designed
for heating.
[0020] As best shown in FIG. 2, the RMFCU 10 is installed on a roof
12. The roof 12 is usually the roof of a building, but may also be
the roof of a room enclosed in a larger space. The roof 12 is
provided with one or several openings for connecting the RMFCU 10
to the various supply and return air ducts. A rooftop curb 14
ensures proper sealing between the unit 10 and the roof 12. As best
shown in FIG. 2, the roof curb 14 includes supply air and return
air duct connections 16 and 18 that connect the RMFCU 10 with the
supply and return air ducts SA and RA, respectively, of the
associated building. A standard roof curb, shown in FIG. 5A, is
roughly 12-inches high whereas the optional raised curb, shown in
FIG. 5B, is higher to accommodate a return air duct that is
provided by the installer.
[0021] Referring now to FIGS. 1-3, the RMFCU 10 includes a
weatherproof cabinet 20 for housing any combination of conditioning
components. The cabinet 20 is of a conventional construction, which
may include a single wall metal exterior that is fully insulated.
The cabinet 20 may also use insulated double wall construction. The
cabinet 20 is generally rectangular in shape, having its major axis
extending generally horizontally. The cabinet 20 includes two side
panels 26 and 28 arranged generally parallel to each other and at
right angles to end panels 30 and 32. An upper panel or top 36 is
affixed to the top edges of the other panels 26, 28, 30, 32 of the
cabinet 20. A base panel 40 supports the cabinet panels 26, 28, 30,
32 and provides a bottom to the cabinet 20. The base panel 40 is
supported by the roof curb 14. Foam tape or other sealing member
(not shown) is preferably interposed between the roof curb 14 and
the base panel 40 to create a water-tight seal therebetween.
[0022] The cabinet 20 also includes a plurality of utility
connections, one or more access doors 48 for servicing, an intake
air hood 50 for supplying fresh air into the cabinet 20, and a
condensation drain pipe connection 52. In the embodiment shown in
FIG. 1, the utility connections include but are not limited to an
electrical power connector 54 located on one of the vertical panels
of the cabinet 20. In this embodiment, an optional control
connector 56 may also be provided. Alternatively, the electrical
power connector may be located underneath the cabinet 20 at base
panel 40 for interfacing with a cooperating connector of the roof
curb 14. The utility connections further include heating and/or
cooling water supply and return connectors 58 and 60 position on
one side or end panel of the cabinet 20. Alternatively, the heating
and/or cooling water supply and return connectors 58 and 60 may be
located underneath the cabinet at base panel 40 for interfacing
with cooperating connectors of the roof curb. It will be
appreciated that the electrical and mechanical connectors may be
any suitable interface known in the art for interfacing with
piping, cabling, electrical wiring, etc., and can be selected for
the particular application. As will be described in detail below,
the cabinet may further include space, including discrete
compartments, for housing pump components, control system
components, power components, or other desired features, etc.
[0023] Inside the cabinet 20 is an air circuit along which are
located the conditioning components. As best shown in FIG. 2, the
air circuit comprises a return air inlet 66 formed in the base
panel 40 of the cabinet 20 for connection with the return air duct
RA of the conditioned space via the return air duct connection 18
of the roof curb 14. The air circuit also comprises a supply air
outlet 68 for connection with the supply air duct SA of the
conditioned space via the supply air duct connection 16 of the roof
curb 14. At least one electric motor powered air supply fan 76 is
mounted in a suitable manner within the cabinet 20 for delivering
conditioned air to the conditioned space through the supply air
outlet 68 and associated ducting. Air is returned from the
conditioned space through the return air duct connection 16 and
into the cabinet via the return air inlet 66.
[0024] The volume of this recirculated air may be controlled by an
optional recirculation damper 78 mounted in the inlet 66. Return
air from the conditioned space mixes with fresh outside air that is
drawn in by the fan 76 through the intake air hood 50. The fan 76
and recirculating damper 78 are operated in a well known manner by
a control system 80 (see FIG. 4) to provide the proper amount of
air to the conditioned space and to recirculate a certain portion
of that air. A set of air filters 84, including a pre-filter 84A
and a primary filter 84B, may be optionally mounted in the stream
of fresh outside air and/or the recirculating air. In one
embodiment, a filter rack with a moveable track may be utilized
that allows for the installation of, for example, 1-inch to 4-inch
thick air filters or the pre-filter 84A and/or primary air filter
84B for improved indoor air quality.
[0025] An optional inlet damper 88 may be mounted over the cabinet
entrance of the hood 50 to control the amount of fresh air that
passes into the cabinet from the hood 50. The inlet damper 88 is
operated by the control system 80. It will be appreciated that
other components may be disposed in communication with the air
supply fan, such as reclaim devices, ultra violet purification
lights, etc.
[0026] The mixed air that is moved through the cabinet 20 is then
urged through temperature conditioning means for varying the
temperature thereof. As aforesaid, the RMFCU 10 may be configured
for cooling and/or heating the air depending on the intended
application. Once the air travels through the temperature varying
means, it enters a plenum chamber 90 fluidly communicating with the
supply air outlet 68 for connection with the supply air duct SA for
providing the conditioned air to the conditioned space.
[0027] As best shown in FIG. 2, the temperature conditioning means
of the RMFCU may include an air cooling device 92 for cooling the
air passed through the cabinet 20. In one embodiment, the air
cooling device 92 includes one or more chilled water coils suitably
mounted within the cabinet in-line with the fresh air delivered via
the air intake hood 50 and/or return air supplied from the return
air duct RA. The chilled water coil(s) are fluidly connected in a
conventional manner via piping 94 (see FIG. 4) to the cooling
return and supply connectors 60 mounted to the cabinet 20 for job
site utility connections. The chilled water coil(s) provide the
RMFCU's cooling capacity and can be matched to any brand of chiller
or type of chilled water system (e.g., campus chilled water or
local package air-cooled chiller).
[0028] Multiple cooling coil sizes are available within each
nominal cabinet size so the HVAC designer can more easily provide a
precise match to the building load than previously available with
conventional package air-cooled RTU equipment. The number of RMFCU
cooling coil variations possible within each cabinet size is a
unique cooling capacity feature for the RMFCU unit as compared to
the package RTU equipment. This cooling flexibility means the RMFCU
can be custom matched to the climate and the building's sensible,
latent and grand total cooling load. In several embodiments, an
optional 2 or 3-inch high by cooling coil width by-pass air damper
may be included for simple dehumidification control. A cooling coil
drain pan may be provided that is double sloped for improved
condensate removal.
[0029] The temperature conditioning means of the RMFCU 10 may
additionally or alternatively include a heating device 96 for
supplying heat to the air stream to be distributed throughout the
conditioned space via the supply air duct SA. In the embodiment
shown in FIG. 2, the heating device 96 may include one or more
heating coils in the form of hot water coils suitably mounted
within the cabinet 20 in-line with the fresh air delivered via the
intake hood 50 and/or the return air supplied via the return duct
connection 18. The hot water coil(s) are fluidly connected in a
conventional manner via piping 98 to the heating return and supply
connectors 58 mounted to the cabinet 20 for job site utility
connections. The hot water coil(s) provide the RMFCU's heating
capacity. The RMFCU may offer several heating hot water coil
options within each cabinet size. The hot water coils are
compatible with any type of hot water source (i.e., low or high
temperature hot water). Alternatively, other heating coils or
heating components may be used, such as heat reclaim coils,
electric heating coils, etc., to supply the thermal energy for
heating the fresh or recirculating air supplied to the conditioned
space.
[0030] The RMFCU 10 further includes one or more fluid circulation
pumps 100 connected in-line between the return or supply connectors
of the cabinet and the chilled water coils and/or heating coils. In
the embodiment shown, the pumps 100 are connected to the supply
side of the coils as opposed to the return side of the coils, but
both configurations are contemplated to be within the scope of the
present invention, as claimed. As described briefly above, the
pumps 100 and associated accessories may be housed in the cabinet
pump compartment 102. In embodiments of the present invention, any
heating or cooling water coil can be matched to the coil
circulation pumps. In accordance with aspects of the present
invention, the circulation pumps are of what is known in the
industry as the monoflow type. One type of monoflow pump that may
be practiced with the embodiments of the present invention is
commercially available from Taco, Inc., Cranston, R.I., and sold
under the trademark LoadMatch.TM.. The pump may be one of many
sizes with varying gpm flow rates for each cabinet size, depending
on its intended application. In one embodiment, the pump may be
sized to offset the internal losses for piping, coil and any piping
accessories.
[0031] In several embodiments of the present invention, the pump
motors are operatively connected to a variable speed drive (VSD)
motor control located within the cabinet 20 as part of the control
system 80. As such, the VSD control provides the water coil's
capacity control in-lieu of conventional control valves. Thus, the
RMFCU is capable of replacing either a single zone air-cooled
package RTU or a RTU intended for application with what the HVAC
industry calls VVT or VAV zone control terminals. VVT is an
industry acronym for an HVAC system using variable air temperature
and variable air volume zone temperature control terminals. VAV is
an industry acronym for an HVAC system using variable air volume
zone temperature control terminals. Embodiments of the present
invention include control options for single zone, VVT and VAV
applications. As described briefly above, the control system 80 may
be housed in the cabinet 20, such as a discrete area or part of
another compartment, such as the power compartment 106.
[0032] The RMFCU 10 may include other components known in the HVAC
industry. For example, the RMFCU 10 may include return air fan(s),
powered exhaust/relief fan(s), relief air outlets, etc., not shown
for ease of illustration but well known in the art.
[0033] In accordance with aspects of the present invention,
embodiments of the RMFCU 10 includes supply air supply fan(s) and
cooling coil combinations that are capable of providing, for
example, from 250 to 500-cfm per nominal ton of capacity. In
several embodiments, the RMFCU supply fans and fan motors can
operate at higher external static pressure for improved performance
on VVT and VAV applications compared to most conventional package
RTU equipment. The RMFCU cabinet can be supplied in several
incremental sizes from 2 to 40 tons and 400-cfm to 15,000-cfm. A
preliminary sample of cabinet sizing is as follows: 1 to 5 tons (or
400 to 2,000-cfm), 6 to 9.4 tons (or 2,400 to 3,750-cfm), 10 to
18.75 tons (or 4,000 to 7,500-cfm), 20 to 25 tons (or 8,000 to
10,000-cfm), 0.27.5 to 37.5 tons (or 11,000 to 15,000-cfm).
[0034] Embodiments of the RMFCUs described and shown herein provide
many advantages over conventional package RTUs, some of which will
now be described. First, because the RMFCU cabinet has no condenser
or compressor sections (like a conventional air-cooled RTU).
Therefore, that portion of the cabinet dedicated to fan and coil
components can be slightly larger. This added space provides
improved performance and the availability of unique options that
are not available with (or do not fit within) the typical
air-cooled RTU product.
[0035] Secondly, because the RMFCU may use a full face
chilled-water cooling coil, the application of variable airflow
does not require the external addition of a supply to return air
duct by-pass damper as is recommended for most air-cooled package
RTUs in a VVT or VAV application. Thirdly, a greater number of
cooling capacity options for each cabinet size are available due to
the more simple use of chilled-water cooling. Fourthly, the
application of chilled water cooling provides improved energy
performance due to closely matched sensible and latent capacity.
Other advantages that can be realized may include the option for
dehumidification control, the inclusion of variable flow pumping
for temperature control and compatibility with a monoflow piping
design, cabinet space for improved air filtration and purification
options, and factory installation and wiring of a supply fan
variable speed drive (VSD) for VAV and VVT applications for
providing energy conservation not obtainable with most small
package air-cooled RTUs.
[0036] Other embodiments of the RMFCU may include the use of a
battery and/or electrical power components compatible with a local
or unit mounted photovoltaic solar panel for providing all, or a
portion of, the fan, pump and control power requirements. To this
end, as described briefly above, the power components may be housed
in the cabinet power compartment 106 and electrically connected to
the electrical power connector mounted on the cabinet. The power
compartment, or other available space within the cabinet, may house
rechargeable batteries or the like for power back-up and/or as a
solar power accessory. It will be appreciated that the power
components may include any device that provides power distribution,
conditioning, surge protection, etc., and may include a standard
120 AC interface for providing power requirements to any tools used
by a serviceman.
[0037] Embodiments of the RMFCU may also improve service access
compared to some traditional air-cooled package RTU units of the
same tonnage and size. Also, the use of chilled water cooling
translates into longer equipment life and cooling diversity that
allows the installation of fewer total compressor tons when
compared to multiple air-cooled RTUs on a single building. Finally,
the total connected electrical load for the RMFCUs is lower with
reduced annual energy consumption. With the inclusion of optional
photovoltaic power generation, the RMFCU should qualify for a LEED
or green building design credit.
[0038] It will be appreciated that other components and/or features
may be included within or use with the RMFCUs. For example, direct
drive plug fans may be used by the RMFCUs. The advantage of a
direct drive plug fan is no motor/belt efficiency losses, lower
operating costs, quieter supply fan operation, and easy conversion
from down flow to horizontal supply air discharge. Also, barometric
relief may be provided with either a fabric or a balanced back
draft damper, as well as powered exhaust fans. The RMFCU can be
provided without controls (for field installation of controls) or
with factory wired controls. Standard factory controls may be
direct digital controls (DDC) with BACNet, LonWorks or modbus ports
for remote monitoring and a control interface. These control ports
and open protocol can minimize the need for factory installed
controls as provided by national manufactures such as Johnson,
Siemens, Alerton, Trane, Carrier, etc.
[0039] While illustrative embodiments have been illustrated and
described, it will be appreciated that various changes can be made
therein without departing from the spirit and scope of the
invention.
* * * * *