U.S. patent application number 15/940945 was filed with the patent office on 2018-10-11 for optimization system and methods for furnaces, heat pumps and air conditioners.
This patent application is currently assigned to THE REGENTS OF THE UNIVERSITY OF CALIFORNIA. The applicant listed for this patent is THE REGENTS OF THE UNIVERSITY OF CALIFORNIA. Invention is credited to Mark Modera.
Application Number | 20180292103 15/940945 |
Document ID | / |
Family ID | 63711267 |
Filed Date | 2018-10-11 |
United States Patent
Application |
20180292103 |
Kind Code |
A1 |
Modera; Mark |
October 11, 2018 |
OPTIMIZATION SYSTEM AND METHODS FOR FURNACES, HEAT PUMPS AND AIR
CONDITIONERS
Abstract
Systems and methods for optimizing system efficiency and demand
response performance for variable-fan-speed and variable-capacity
air handling systems. A controller is provided selectively
controlling building-zone dampers in response to acquired
operational parameters, such that air flows through selected duct
sections and not through the entire duct system simultaneously,
wherein design velocity in each duct section is roughly maintained
whenever the duct section is being used. Exemplary operational
parameters include compressor speed, cooling capacity, heating
capacity, fan speed, duct-section air flow, zone air flow,
duct-inlet temperature, duct-outlet temperature, and duct-zone
temperature.
Inventors: |
Modera; Mark; (Piedmont,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA |
Oakland |
CA |
US |
|
|
Assignee: |
THE REGENTS OF THE UNIVERSITY OF
CALIFORNIA
Oakland
CA
|
Family ID: |
63711267 |
Appl. No.: |
15/940945 |
Filed: |
March 29, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62478135 |
Mar 29, 2017 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24F 13/02 20130101;
F24F 2110/30 20180101; F24F 11/46 20180101; F24F 2120/20 20180101;
F24F 11/79 20180101; F24F 13/10 20130101; F24F 3/02 20130101; F24F
2140/40 20180101; F24F 11/74 20180101 |
International
Class: |
F24F 11/79 20060101
F24F011/79; F24F 13/10 20060101 F24F013/10; F24F 13/02 20060101
F24F013/02; F24F 11/74 20060101 F24F011/74; F24F 3/02 20060101
F24F003/02 |
Claims
1. An apparatus for optimizing system efficiency and demand
response performance of an air-handling system, the air-handling
system comprising a duct system having a plurality of duct sections
and one or more dampers for controlling distribution of air into
the plurality of duct sections, the apparatus comprising: (a) a
system controller coupled to the one or more dampers; and (b) said
system controller comprising a processor and a non-transitory
memory storing instructions executable on the processor to perform
steps comprising: (i) acquiring one or more operational parameters
associated with the air-handling system; (ii) selectively
controlling the one or more dampers based on the one or more
operational parameters such that that airflow is only directed
through selected duct sections of the one or more duct sections and
not through the entire duct system simultaneously; and (iii)
maintaining one or more of design velocity, heating capacity, and
cooling capacity in each duct section in which airflow is directed
to optimize one or more of system efficiency and demand response
performance of the air-handling system.
2. The apparatus of claim 1, wherein the air handling system
further comprises a compressor or burner for conditioning the
airflow and a fan for distributing airflow into the one or more
duct sections, and each of the one or more duct sections
corresponds with a zone to be conditioned: wherein maintaining one
or more of design velocity, heating capacity, and cooling capacity
in each duct section comprises adjusting one or more of a speed of
the fan and a speed of the compressor or burner to a fraction of a
100% operation flow represented by a zone when only one zone is
being called for conditioning or to a fraction of the 100%
operation flow represented by a sum of all zones being called for
conditioning.
3. The apparatus of claim 2: wherein the one or more operational
parameters comprise a call for capacity reduction from the
air-handling unit or a utility supplying power to the air-handling
unit; and wherein selectively controlling one or more dampers
comprises determining if the capacity reduction that is called for
is less than a sum of a capacity of two or more zones presently
being called for conditioning, and cycling the airflow to the duct
sections corresponding to the two or more zones such that only one
of the two or more zones is receiving distributed airflow at any
given time during the call for capacity reduction.
4. The apparatus of claim 3, wherein three zones are being called
for conditioning, and wherein cycling the airflow to the duct
sections comprises: controlling the one or more dampers such that
airflow is delivered to a first duct section corresponding to a
first zone while airflow is restricted to second and third duct
sections for a first period of time, airflow is delivered to a
second duct section corresponding to a second zone while airflow is
restricted to first and third duct sections for a second period of
time, and airflow is delivered to a third duct section
corresponding to a third zone while airflow is restricted to first
and second and third duct sections for a third period of time.
5. The apparatus of claim 3: wherein the one or more operational
parameters comprises one or more temperature readings from sensors
located within the air-handling system and coupled to the
controller; wherein cycling of the airflow to the duct sections is
only performed if a temperature effect threshold is not met, the
temperature effect threshold being a function of the one or more
temperature readings.
6. The apparatus of claim 5, wherein the temperature effect
threshold is a function of one or more of measured temperatures
from sensors located in the one or more ducts, a predicted
duct-zone temperature, or a duct R-value.
7. The apparatus of claim 5, wherein the temperature effect
threshold is a function of one or more of a measured temperature
variation through a duct section, a measured temperature variation
between a supply plenum and a return plenum of the duct system, or
a temperature at one or more the grilles distributing airflow from
the one or more duct sections.
8. The apparatus of claim 3, wherein the capacity of two or more
zones is selected from the group consisting of: compressor or
burner speed, fan speed, cooling capacity, or heating capacity.
9. The apparatus of claim 3, wherein the capacity of two or more
zones is selected from the group consisting of: duct-section air
flow, zone air flow, duct-inlet temperature, duct-outlet
temperature, and duct-zone temperature.
10. The apparatus of claim 3, further comprising: manipulating fan
speed so as to decrease fan speed less than a specified decrease in
compressor or burner speed or decrease in system capacity
associated with the call for capacity reduction.
11. A method for optimizing system efficiency and demand response
performance of an air-handling system the air-handling system
comprising a duct system having a plurality of duct sections and
one or more dampers for controlling distribution of air into the
plurality of duct sections, the method comprising: acquiring one or
more operational parameters associated with the air-handling
system; selectively controlling the one or more dampers based on
the one or more operational parameters such that that airflow is
only directed through selected duct sections of the one or more
duct sections and not through the entire duct system
simultaneously; and maintaining one or more of design velocity,
heating capacity, and cooling capacity in each duct section in
which airflow is directed to optimize one or more of system
efficiency and demand response performance of the air-handling
system; wherein said method is performed by a processor executing
instructions stored on a non-transitory medium.
12. The method of claim 11, wherein the air handling system further
comprises a compressor or burner for conditioning the airflow and a
fan for distributing airflow into the one or more duct sections,
and each of the one or more duct sections corresponds with a zone
to be conditioned: wherein maintaining one or more of design
velocity, heating capacity, and cooling capacity in each duct
section comprises adjusting one or more of a speed of the fan and a
speed of the compressor or burner to a fraction of a 100% operation
flow represented by a zone when only one zone is being called for
conditioning or to a fraction of the 100% operation flow
represented by a sum of all zones being called for
conditioning.
13. The method of claim 12: wherein the one or more operational
parameters comprise a call for capacity reduction from the
air-handling unit or a utility supplying power to the air-handling
unit; and wherein selectively controlling one or more dampers
comprises determining if the capacity reduction that is called for
is less than a sum of a capacity of two or more zones presently
being called for conditioning, and cycling the airflow to the duct
sections corresponding to the two or more zones such that only one
of the two or more zones is receiving distributed airflow at any
given time during the call for capacity reduction.
14. The method of claim 13, wherein three zones are being called
for conditioning, and wherein cycling the airflow to the duct
sections comprises: controlling the one or more dampers such that
airflow is delivered to a first duct section corresponding to a
first zone while airflow is restricted to second and third duct
sections for a first period of time, airflow is delivered to a
second duct section corresponding to a second zone while airflow is
restricted to first and third duct sections for a second period of
time, and airflow is delivered to a third duct section
corresponding to a third zone while airflow is restricted to first
and second and third duct sections for a third period of time.
15. The method of claim 13: wherein the one or more operational
parameters comprises one or more temperature readings within the
air-handling system; wherein cycling of the airflow to the duct
sections is only performed if a temperature effect threshold is not
met, the temperature effect threshold being a function of the one
or more temperature readings.
16. The method of claim 15, wherein the temperature effect
threshold is a function of one or more of measured temperatures
from sensors located in the one or more ducts, a predicted
duct-zone temperature, or a duct R-value.
17. The method of claim 15, wherein the temperature effect
threshold is a function of one or more of a measured temperature
variation through a duct section, a measured temperature variation
between a supply plenum and a return plenum of the duct system, or
a temperature at one or more the grilles distributing airflow from
the one or more duct sections.
18. The method of claim 13, wherein the capacity of two or more
zones is selected from the group consisting of: compressor or
burner speed, fan speed, cooling capacity, or heating capacity.
19. The method of claim 13, wherein the capacity of two or more
zones is selected from the group consisting of: duct-section air
flow, zone air flow, duct-inlet temperature, duct-outlet
temperature, and duct-zone temperature.
20. The method of claim 13, further comprising: manipulating fan
speed so as to decrease fan speed less than a specified decrease in
compressor or burner speed or decrease in system capacity
associated with the call for capacity reduction.
21. An air-handling system optimized for efficiency and demand
response performance, comprising: (a) an air-handling unit; (b) a
duct system coupled to the air handling unit, the duct system
comprising a plurality of duct sections and one or more dampers for
controlling distribution of air into the plurality of duct
sections, the apparatus comprising: (c) a system controller coupled
to the one or more dampers and air handling unit; and (d) said
system controller comprising a processor and a non-transitory
memory storing instructions executable on the processor to perform
steps comprising: (i) acquiring one or more operational parameters
associated with the air-handling system; (ii) selectively
controlling the one or more dampers based on the one or more
operational parameters such that that airflow is only directed
through selected duct sections of the one or more duct sections and
not through the entire duct system simultaneously; and (iii)
maintaining one or more of design velocity, heating capacity, and
cooling capacity in each duct section in which airflow is directed
to optimize one or more of system efficiency and demand response
performance of the air-handling system.
22. The system of claim 21, wherein the air handling unit further
comprises a compressor or burner for conditioning the airflow and a
fan for distributing airflow into the one or more duct sections,
and each of the one or more duct sections corresponds with a zone
to be conditioned: wherein maintaining one or more of design
velocity, heating capacity, and cooling capacity in each duct
section comprises adjusting one or more of a speed of the fan and a
speed of the compressor or burner to a fraction of a 100% operation
flow represented by a zone when only one zone is being called for
conditioning or to a fraction of the 100% operation flow
represented by a sum of all zones being called for
conditioning.
23. The system of claim 22: wherein the one or more operational
parameters comprise a call for capacity reduction from the
air-handling unit or a utility supplying power to the air-handling
unit; and wherein selectively controlling one or more dampers
comprises determining if the capacity reduction that is called for
is less than a sum of a capacity of two or more zones presently
being called for conditioning, and cycling the airflow to the duct
sections corresponding to the two or more zones such that only one
of the two or more zones is receiving distributed airflow at any
given time during the call for capacity reduction.
24. The system of claim 23, wherein three zones are being called
for conditioning, and wherein cycling the airflow to the duct
sections comprises: controlling the one or more dampers such that
airflow is delivered to a first duct section corresponding to a
first zone while airflow is restricted to second and third duct
sections for a first period of time, airflow is delivered to a
second duct section corresponding to a second zone while airflow is
restricted to first and third duct sections for a second period of
time, and airflow is delivered to a third duct section
corresponding to a third zone while airflow is restricted to first
and second and third duct sections for a third period of time.
25. The system of claim 23, further comprising one or more sensors
located within the air handling system and coupled to the system
controller: wherein the one or more operational parameters
comprises one or more temperature readings from the one or more
sensors within the air-handling system; wherein cycling of the
airflow to the duct sections is only performed if a temperature
effect threshold is not met, the temperature effect threshold being
a function of the one or more temperature readings.
26. The system of claim 25, wherein the temperature effect
threshold is a function of one or more of measured temperatures
from sensors located in the one or more ducts, a predicted
duct-zone temperature, or a duct R-value.
27. The system of claim 25, wherein the temperature effect
threshold is a function of one or more of a measured temperature
variation through a duct section, a measured temperature variation
between a supply plenum and a return plenum of the duct system, or
a temperature at one or more the grilles distributing airflow from
the one or more duct sections.
28. The system of claim 23, wherein the capacity of two or more
zones is selected from the group consisting of: compressor or
burner speed, fan speed, cooling capacity, or heating capacity.
29. The system of claim 23, wherein the capacity of two or more
zones is selected from the group consisting of: duct-section air
flow, zone air flow, duct-inlet temperature, duct-outlet
temperature, and duct-zone temperature.
30. The system of claim 23, further comprising: manipulating fan
speed so as to decrease fan speed less than a specified decrease in
compressor or burner speed or decrease in system capacity
associated with the call for capacity reduction.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to, and the benefit of U.S.
provisional patent application Ser. No. 62/478,135 filed on Mar.
29, 2017, incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION
[0003] A portion of the material in this patent document may be
subject to copyright protection under the copyright laws of the
United States and of other countries. The owner of the copyright
rights has no objection to the facsimile reproduction by anyone of
the patent document or the patent disclosure, as it appears in the
United States Patent and Trademark Office publicly available file
or records, but otherwise reserves all copyright rights whatsoever.
The copyright owner does not hereby waive any of its rights to have
this patent document maintained in secrecy, including without
limitation its rights pursuant to 37 C.F.R. .sctn. 1.14.
BACKGROUND
1. Technical Field
[0004] The technology of this disclosure pertains generally to
heating and cooling equipment, and more particularly to
optimization systems and methods for heating and cooling
equipment.
2. Background Discussion
[0005] Existing controls for variable capacity heating and cooling
equipment do not consider changes in the performance of the duct
system associated with changing the speed of the fan and changing
the heating/cooling capacity of the equipment. Thus, current
control strategies result in dramatically sub-optimal performance
(energy efficiency and comfort).
[0006] FIG. 1 shows measured performance of a state of the art
residential, split-system, variable-capacity air conditioner
operated with a typical duct system (R-6) located in the same
temperature condition as the outdoor unit. This figure shows that
reducing capacity and fan speed initially increases system
efficiency (cooling at grilles) under mild conditions, but
decreases system efficiency once the capacity/fan-speed drops below
a certain level. As the duct-zone temperature increases, the
optimal capacity/fan-speed increases, reaching 100% somewhere
between 105.degree. F. and 115.degree. F. in the duct zone. Many
ducts in existing homes are in attics, where temperatures typically
exceed outdoor temperature.
BRIEF SUMMARY
[0007] The technology of this disclosure solves problems associated
with current equipment control strategies by characterizing duct
system performance with a few readily available parameters, and
using a simplified algorithm to adjust equipment operating
parameters (fan speed, capacity, and damper positions). In general
terms, this disclosure describes a methodology for controlling a
variable speed heat pump, furnace or air conditioner to maximize
the overall efficiency of the entire system. In one embodiment,
this is accomplished by managing fan speed, compressor/burner
capacity, and a zone-damper system, to optimize system efficiency
by considering thermal losses from ducts, fan power and compressor
efficiency. The technology requires minimal changes in hardware
(e.g. in some embodiments one or more additional temperature
sensors), but has the capability to increase system efficiency by
20-300%, depending upon conditions, as a result of the joint
optimization of performance.
[0008] Further aspects of the technology described herein will be
brought out in the following portions of the specification, wherein
the detailed description is for the purpose of fully disclosing
preferred embodiments of the technology without placing limitations
thereon.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0009] The technology described herein will be more fully
understood by reference to the following drawings which are for
illustrative purposes only:
[0010] FIG. 1 is a plot showing measured performance of a state of
the art residential, split-system, variable-capacity air
conditioners operated with a typical duct system (R-6) located in
the same temperature condition as the outdoor unit.
[0011] FIG. 2 is a schematic system diagram of a system for
improving the energy efficiency and comfort performance of
variable-speed/capacity heating and cooling equipment.
[0012] FIG. 3 is a schematic system diagram of an alternative
system for improving the energy efficiency and comfort performance
of variable-speed/capacity heating and cooling equipment without
use of sensors.
[0013] FIG. 4 shows a schematic flow diagram of a capacity-based
zone cycling method for improving the energy efficiency and comfort
performance of variable-speed/capacity heating and cooling
equipment.
[0014] FIG. 5 shows a schematic flow diagram of one embodiment of
the cycling step of FIG. 4.
[0015] FIG. 6 shows a temperature and capacity based zone cycling
method for improving the energy efficiency and comfort/performance
of variable-speed/capacity heating and cooling equipment.
[0016] FIG. 7 is a plot showing measured duct delivery
effectiveness vs. synchronized reductions in compressor and fan
speed for various temperatures.
[0017] FIG. 8 is a plot showing system-efficiency improvements for
a capacity-based method for improving the energy efficiency and
comfort/performance of variable-speed/capacity heating and cooling
equipment via zone cycling.
[0018] FIG. 9 is a plot showing delivery efficiency vs. temperature
for various zone-damper operating modes.
DETAILED DESCRIPTION
[0019] In general terms, the technology of the present description
includes systems and methods for characterizing duct system
performance via a few readily available parameters, and using a
computerized controller with computer program instructions that
adjust equipment operating parameters (fan speed, capacity, and
damper positions) to optimize system performance. FIGS. 2 and 3
show schematic diagrams of two systems for improving the energy
efficiency and comfort performance of variable-speed/capacity
heating and cooling equipment. FIG. 4 through FIG. 6 show various
methods, by way of example, and not of limitation, that may be
implemented as instructions for controlling (i.e. adjusting
operating parameters) the systems shown in FIG. 2 and FIG. 3.
[0020] It is appreciated that the systems and methods disclosed
herein may be used with various Heating, Ventilation, and Air
Conditioning (HVAC) systems, also herein referred to as air
handling system, which may include but are not limited to:
furnaces, heat pumps, air conditioners, or the like. It is also
appreciated that while certain systems and/or methods may be
described herein with respect to a particular implementation or
embodiment (e.g. cooling protocol for an air conditioning system),
any of the embodiments and methods may be variously interchangeable
with any HVAC system, method, or component thereof.
[0021] Referring to FIG. 2, a system 10 is shown for improving the
energy efficiency and comfort and/or performance of
variable-speed/capacity heating and cooling equipment. FIG. 2 and
FIG. 3 show schematic diagrams of the system of the present
description. Components detailed therein are not to scale, and any
relative placement, orientation, or grouping of components shown
therein may be modified, interchanged, duplicated or removed in
various preferred embodiments according to the type of heating,
ventilation or cooling system and space, building or environment to
be conditioned.
[0022] The system 10 generally comprises an air-handling or HVAC
unit 12 having a burner/compressor 34 for conditioning the air and
fan 32 for moving air from return plenum 16 to the supply plenum
18. A system controller 14, (e.g. computer, controller or the like
processing device) is coupled to the HVAC unit 12 and comprises a
processor 40, and application software 42 stored in memory 44 and
executable on the processor 40 for controlling operation of one or
more components within the system 10. The controller 14 is also
coupled to one or more dampers 20 located at or downstream from the
supply plenum 18. The controller 14 is configured to operating the
dampers 20 to control distribution to a plurality of duct sections
22, 24, and 26 that distribute the conditioned air to the building
via a plurality of grilles 25. While three duct sections 22, 24,
and 26 are shown in FIG. 2, it is appreciated that any number,
shape, or orientation may be employed to the duct sections and/or
grilles 25.
[0023] The controller 14 may optionally be coupled to one or more
sensors (e.g. temperature and/or pressure sensors or the like)
located in the system 10 for providing feedback on system
operation/performance. In one embodiment, sensors 30a and 30b are
positioned at or near the return plenum 16 and supply plenum 18,
respectively. In another embodiment, sensors 30c are positioned
within the duct sections 22, 24, and 26 and/or sensors 30d at or
near grilles 25.
[0024] FIG. 3 is a schematic system diagram of an alternative
system 50 for improving the energy efficiency and comfort and/or
performance of variable-speed/capacity heating and cooling
equipment without use of sensors. In system 50, the controller 14
is configured to operating the dampers 20 to control distribution
to a plurality of four duct sections 22, 24, 26, and 28 that
distribute the conditioned air to the building via a plurality of
grilles 25 without the use of sensors. While four duct sections 22,
24, 26, and 28 are shown in FIG. 3, it is appreciated that any
number, shape, or orientation may be employed to the duct sections
and/or grilles 25.
[0025] The system 50 generally comprises an HVAC unit 12 having a
burner/compressor 34 for conditioning the air and fan 32 for moving
air from return plenum 16 to the supply plenum 18. A processing
unit 14, (e.g. computer, controller or the like) is coupled to the
HVAC unit 12 and comprises a controller/processor 40, and
application software 42 stored in memory 44 and executable on the
controller 14 for controlling operation of one or more components
within the system 10.
[0026] Application software 42 may comprise instructions in the
form of machine readable code for operating systems 10 and/or 50 an
accordance with the following exemplary control methods.
[0027] FIG. 4 shows a schematic flow diagram of a first example of
a capacity-based zone cycling method 60 for improving the energy
efficiency and comfort/performance of variable-speed/capacity
heating and cooling equipment without use of sensors, e.g. via a
system such as the system 50 shown in FIG. 3. Algorithm 1 (detailed
below) also provides an exemplary algorithm or logic flow for
computer readable instructions the may be implemented as code for
application software 42 for implementation of method 60 in a system
having three duct sections in accordance with the present
description. Zone/section dampers 20 are controlled such that when
capacity is reduced (e.g., when compressor 34 speed is reduced),
all air goes through one, two or three of the duct sections 22, 24
and 26 (versus the entire system), sequencing through all building
zones calling for conditioning, and roughly maintaining design
velocity in each duct section whenever it is being used and at all
fan/capacity reduction levels. The "zone cycling" approach of
method 60 avoids thermal losses through duct sections that are not
being used at that time, while also considering static pressure and
fan 32 power.
[0028] Referring to FIG. 4, after system start at 61, thermostats
at the various zones provide data to the controller 14, and a
determination is made at step 62 as to which zones need
conditioning. At step 64, one or more dampers 20 are opened or
closed based on which zone or zones were determined to need
conditioning in step 116. At step 66, compressor 34 and/or fan 32
speed are set according to a desired percentage of operation flow
for the allocated zone or zones.
[0029] At step 68, an assessment is made as to whether a call for
capacity reduction is made on the unit 12. Capacity reduction may
be requested from either a local utility providing power to the
unit 12, or within programming inherent to the unit 12 itself. If
no capacity reduction is requested, then the routine loops back to
zone conditioning step 62.
[0030] If capacity reduction is requested, a determination is made
at step 70 as to whether the requested capacity reduction (e.g.
demand-response event asking for a certain percentage curtailment
of power draw) is less than the combined capacity of the zones
being allocated. If the requested capacity reduction is less than
the combined capacity of the zones delivering air, then the routine
loops back to zone conditioning step 62 until a requested capacity
reduction is found to be greater than the combined capacity of the
zones being allocated. At that point, the proper zone cycling
scheme is employed at 72. The zones are then measured again at step
114 for further iterations.
[0031] FIG. 5 shows an exemplary zone cycling step 72 for a system
having 3 ducts, wherein all three ducts are being allocated for
delivery of conditioned air. It is appreciated that zone cycling
step 72 may vary depending on the combination of zone called on for
air conditioning, see logic flow of Algorithm 1. In the exemplary
configuration of FIG. 5, dampers to zones 2 and 3 are closed at
step 74 (while zone 1 remains running) for a specified period of
time T (or lesser time if zone 1 is no longer called for
conditioning). At step 76, dampers to zones 1 and 3 are closed
while the damper to zone 2 is opened for time T (or lesser time if
zone 2 is no longer called for conditioning). Finally, at step 78,
dampers to zones 1 and 2 are closed while the damper to zone 3 is
opened for time T (or lesser time if zone 3 is no longer called for
conditioning). Upon completion of the cycle, the routine loops back
to zone conditioning step 62.
[0032] Algorithm 1:
Definitions
[0033] Cap1: Capacity and air flow associated with design flow for
Zone 1
[0034] Cap2: Capacity and air flow associated with design flow for
Zone 2
[0035] Cap3: Capacity and air flow associated with design flow for
Zone 3
[0036] CAPT: Total capacity and flow (in this case
Cap1+Cap2+Cap3)
[0037] D1: Damper to Zone 1
[0038] D2: Damper to Zone 2
[0039] D3: Damper to Zone 3
[0040] Condition A: Zone 1 calls for conditioning
[0041] Condition B: Zone 2 calls for conditioning
[0042] Condition C: Zone 3 calls for conditioning
[0043] CAPRED: Utility or internal equipment logic calls for
capacity reduction implies CAPRED=TRUE
[0044] CapX: Reduced capacity called for when CAPRED=TRUE
[0045] IF A AND NOT CAPRED
Operate at (Cap1)
D2=Closed
D3=Closed
[0046] IF B AND NOT CAPRED
Operate at (Cap2)
D1=Closed
D3=Closed
[0047] IF C AND NOT CAPRED
Operate at (Cap3)
D1=Closed
D2=Closed
[0048] IF A AND B AND NOT CAPRED
Operate at (Cap1+Cap2)
D3=Closed
[0049] IF A AND C AND NOT CAPRED
Operate at (Cap1+Cap3)
D2=Closed
[0050] IF B AND C AND NOT CAPRED
Operate at (Cap2+Cap3)
D1=Closed
[0051] IF A AND B AND C AND NOT CAPRED
Operate at CAPT
[0052] In a situation where Utility or internal equipment logic
calls for capacity reduction to CAPRED
[0053] IF A AND CAPRED
Operate at (Cap1)
D2=Closed
D3=Closed
[0054] IF B AND CAPRED
Operate at (Cap2)
D1=Closed
D3=Closed
[0055] IF C AND CAPRED
Operate at (Cap3)
D1=Closed
D2=Closed
[0056] IF A AND B AND CAPRED
D3=Closed
If CapX<(Cap1+Cap2)
[0057] Operate at (Cap1) for the lesser of time T (OR until A is
FALSE) with D2=closed
THEN
[0058] Operate at (Cap2) for the lesser of time T (OR until B is
FALSE) with D1=closed
ELSE
Operate at (Cap1+Cap2)
[0059] IF A AND C AND NOT CAPRED
D2=Closed
If CapX<(Cap1+Cap3)
[0060] Operate at (Cap1) for the lesser of time T (OR until A is
FALSE) with D3=closed
THEN
[0061] Operate at (Cap3) for the lesser of time T (OR until C is
FALSE) with D1=closed
ELSE
Operate at (Cap1+Cap3)
[0062] IF B AND C AND NOT CAPRED
D1=Closed
If CapX<(Cap2+Cap3)
[0063] Operate at (Cap2) for the lesser of time T (OR until B is
FALSE) with D3=closed
THEN
[0064] Operate at (Cap3) for the lesser of time T (OR until C is
FALSE) with D2=closed
ELSE
Operate at (Cap2+Cap3)
[0065] IF A AND B AND C AND CAPRED
Operate at (Cap1) for the lesser of time T (OR until A is FALSE)
with D2=closed AND D3=closed
THEN
[0066] Operate at (Cap2) for the lesser of time T (OR until B is
FALSE) with D1=closed AND D3=closed
THEN
[0067] Operate at (Cap3) for the lesser of time T (OR until C is
FALSE) with D1=closed AND D2=closed
[0068] One exemplary configuration of the system-efficiency
improvements of method 60 may be implemented in a system 50 (FIG.
3) operating at 2000 cfm (@ 100% operation) with variable-capacity
heat pump 12 serving 4 building zones serviced by duct sections 22
through 28 (Zone 1 moves 800 cfm, Zone 2 to Zone 4 each move 400
cfm, wherein each zone can call for conditioning separately),
having control logic parameters as follows:
[0069] A) If one zone calls for conditioning: [0070] i. open the
damper 20 for that zone; [0071] ii. set the compressor 34 and fan
32 speed to the fraction of the 100% operation flow represented by
that zone (i.e. 40% for Zone 1, 20% for other Zones).
[0072] B) If more than one zone calls for conditioning: [0073] i.
open the dampers 20 for all zones calling for conditioning; [0074]
ii. Set the compressor 34 and fan 32 speed to the fraction of the
100% operation flow represented by the sum of all zones calling for
conditioning (e.g. 60% for Zone 1 plus Zone 3).
[0075] C) If there is a demand-response event asking for a 60%
curtailment of power draw (i.e. 40% compressor speed) and two zones
call for conditioning: [0076] i. set the compressor 34 and fan 32
speed to 40%; [0077] ii. if it is some combination of Zones 2, 3,
4: [0078] 1. open the dampers for the two zones calling for
conditioning; [0079] iii. if it is a combination Zone 1 plus one of
Zones 2, 3, 4: [0080] 1. open the damper for Zone 1 for 6 minutes,
and then close that damper; and [0081] 2. open only the damper for
the other zone calling for conditioning for 6 minutes while
reducing the fan and compressor to 20%; [0082] 3. alternatively
(e.g. if the compressor cannot operate at 20%), open the dampers to
two of the 20% zones, one being the zone calling for conditioning,
and the other not.
[0083] When cycling the zone dampers 20 to condition more than one
building zone at reduced capacity, the duct section serving each
building zone can be activated for time T lasting several minutes
(e.g. 5-15 minutes) to minimize cycling losses (although the
control could also include zone over-run to capture heating or
cooling in the duct mass).
[0084] In an alternative embodiment, the duct sections can be
cycled through more quickly (e.g. 2-5 minutes) to provide less
swing in building-zone temperatures (although this will be less
efficient).
[0085] Method 60 may also include a building-zone prioritization
scheme (e.g. varying time T for cycling steps 74 through 78).
Method 60 may also be implemented based upon a duct efficiency
model that can be used to calculate and optimize overall system
efficiency.
[0086] The capacity-based zone cycling method 60 minimizes duct
thermal losses (without using excessive fan 32 power) at any given
capacity while maintaining the desired reduction in heating or
cooling capacity (e.g. to increase equipment efficiency and/or
limit electrical power draw). This contrasts with conventional
systems where the entire duct system is used simultaneously.
[0087] FIG. 6 shows a schematic flow diagram of a temperature and
capacity-based zone cycling method 80 for improving the energy
efficiency and comfort performance of variable-speed/capacity
heating and cooling equipment. In method 80, sensor data, such as
the measured or predicted duct zone temperature, along with the
duct insulation R-value (and possibly zone layout for more
precision), are used to determine when to utilize zone cycling. In
a preferred embodiment, method 80 is implemented in a system such
as system 10 shown in FIG. 2, wherein one or more sensors 30a, 30b,
30c and 30d may be used to provide additional optimization to the
system.
[0088] Referring to FIG. 6, after system start at 82, a
determination is made at step 84 as to which zones need
conditioning (e.g. from data provided by one or more thermostats
(not shown) in the zones). At step 86, one or more dampers 20 are
opened or closed based on the conditioning zones determined in step
116. At step 88, burner/compressor 34 and/or fan 32 speed are set
according to a desired percentage of operation flow for the
allocated zone or zones.
[0089] At step 90, an assessment is made as to whether a call for
capacity reduction is made on the unit 12. Capacity reduction may
be requested from either a local utility providing power to the
unit 12, or within programming inherent to the unit 12 itself. If
no capacity reduction is requested, then the routine loops back to
zone conditioning step 84.
[0090] If capacity reduction is requested, a determination is made
at step 90 as to whether the requested capacity reduction (e.g.
demand-response event asking for a certain percentage curtailment
of power draw) is less than the combined capacity of the zones
being allocated. If the requested capacity reduction is less than
the combined capacity of the zones delivering air, then the routine
loops back to zone conditioning step 84 until a requested capacity
reduction is found to be greater than the combined capacity of the
zones being allocated.
[0091] If the requested capacity reduction is less than the
combined capacity of the zones delivering air, a determination is
then made at step 92 that takes into consideration temperature data
provided by one or more of sensors 30a, 30b, 30c, and 30d as to
whether a temperature defect threshold has been met. If a specified
temperature defect is within threshold the routine loops back to
zone conditioning step 84. If the specified temperature defect is
outside a given threshold, then a zone cycling process, such
cycling process 80 detailed in FIG. 5 or any of the processes
detailed in Algorithm 1 are used to cycle the delivery to one or
more of the allocated duct sections 22, 24 and 26. In one exemplary
cooling configuration, the building-zone cycling process 94 is be
initiated whenever the duct-zone temperature (e.g. measured via
sensors 30c) exceeds 95.degree. F. for R-6 ductwork or 90.degree.
F. for R-4 ductwork.
[0092] After the proper zone cycling scheme 94, the routine loops
back to zone conditioning step 84.
[0093] The method 80 may also be variably configured based upon the
duct system design and location, measured or predicted temperatures
in the duct zones/sections 22, 24, 26, and/or based upon a duct
efficiency model that can be used to calculate and optimize overall
system efficiency.
[0094] In a further refinement of the above disclosed embodiments,
the methods 60 or 80 may be modified to specify conditions where
the indoor fan 32 speed is decreased less than the decrease in
compressor 34 speed or system capacity (this may result in an
increase in fan speed depending on the specified capacity
decrease). Keeping the fan speed reduction less than the capacity
reduction reduces the residence time in the ductwork and the
temperature difference across the duct walls, thereby reducing
thermal losses. Although this increases fan power, the increase in
fan power can be more than compensated for by increases in delivery
effectiveness. It also impacts the sensible heat ratio, so its use
can also better address low-humidity cooling loads, but can be
constrained by high-humidity cooling loads. The above fan speed
manipulation may be implemented based upon the duct system design
and location, measured temperatures in the duct zone or grilles
(e.g. with sensors 30c and 30d, respectively), and/or based upon a
duct efficiency model that can be used to calculate and optimize
overall system efficiency.
[0095] In yet a further refinement, the temperature and
capacity-based zone cycling method 80 of FIG. 6 may incorporate
sensor measurements of temperature at some (or all) grilles 25. In
a preferred embodiment, the algorithm optimizes overall system
efficiency based upon measured differences between grille
temperatures (e.g. at sensors 30d) and the supply plenum
temperature (e.g. at sensor 30b). This implementation of method 80
may use more hardware (i.e. temperature sensors), but also have the
benefits of being is more flexible and automatic from a control
perspective. For example, the building-zone cycling step 94 in
method 80 may be initiated whenever the temperature rise through a
duct section exceeds 30% of the temperature drop between the supply
plenum 18 (as measured by sensor 30b) and return plenum 16 (as
measured by sensor 30a) during cooling operation. Such
implementation may also take into consideration measured
temperatures in the grilles 25, and may incorporate a duct
efficiency model that can be used to calculate and optimize overall
system efficiency.
[0096] Fan speed manipulation where fan speed is reduced less than
the reduction in compressor speed or system capacity may also be
incorporated in such implementation.
[0097] It is also appreciated building-zone cycling in accordance
with the methods above avoids thermal losses through duct sections
that are not being used at that time, and may also consider duct
static pressure (e.g. via pressure sensors at sensor locations
30c). This implementation minimizes duct thermal losses (without
excessive fan power) at any given capacity while maintaining the
desired limitation on heating or cooling capacity (whether to
increase equipment efficiency or limit electrical power draw for
demand response). Keeping the fan-speed reduction smaller than the
capacity reduction reduces residence time in the ductwork and the
temperature difference across the duct walls, thereby reducing duct
thermal losses. However, because increasing fan speed increases
sensible heat ratio, the use of this technique is constrained by
higher humidity loads. Increasing fan speed also increases fan
power, so the control algorithm of method 80 may be structured to
determine the trade-off between fan power and delivery
effectiveness.
[0098] It is appreciated that the systems and methods detailed
above may factor any of the following considerations for
optimization of the air handling unit 12: compressor/burner speed,
cooling capacity, heating capacity, fan speed, duct-section air
flow, zone air flow, duct-inlet temperature, duct-outlet
temperature, and duct-zone temperature, duct R-value, duct-system
layout, etc.
[0099] Results
[0100] Laboratory tests conducted to measure performance benefits
of the systems and methods of the present description over existing
systems.
[0101] FIG. 7 shows a plot of the measured duct delivery
effectiveness (the primary driver for the reduction in performance
at high temperatures) at 85.degree. F., 95.degree. F., 105.degree.
F. and 115.degree. F. at varying compressor/fan speed percentages.
FIG. 7 shows exemplary results for a system 10/50 having
application software 42 configured for executing instructions in
accordance with the method 60 of FIG. 4.
[0102] FIG. 8 shows plot of the system efficiency improvement
achieved using the embodiment of method 60 (FIG. 4). For this
embodiment, a complete duct system as shown in the system 50 of
FIG. 3 was divided into four zones (22-28), each with a damper 20
located at the exit of the supply-air plenum 18 (i.e. adjacent to
the air conditioner 12 cooling coil (not shown)). Each damper 20
was controlled manually to include or exclude that zone from the
air flow leaving the air conditioner. The entire duct system was
placed in a laboratory environmental chamber whose temperature was
precisely controlled. The cooling energy that would be delivered to
the building was measured by measuring the air flow and temperature
at each supply grille 25 (entry point into the building at the end
of each duct run). This experimental set-up allows the savings
associated with employing the sensor-free embodiment of FIG. 3 and
FIG. 4.
[0103] The results in FIG. 8 show the overall system efficiency
improvements associated with synchronizing the duct-system design
airflow to the desired fan flow and cooling capacity of the heat
pump. The base case is to utilize the entire duct system at all
capacity/fan-flow combinations. FIG. 8 shows the system efficiency
improvement to range between 20% and 80% compared to operation
without zoning between 60% and 25% capacity, respectively. FIG. 8
includes simulation and laboratory test data, which show that
measurements agree with the model.
[0104] FIG. 9 shows a plot of the measured duct delivery
effectiveness at 40% compressor speed at 85.degree. F., 95.degree.
F., 105.degree. F. and 115.degree. F. at varying zone conditions:
1) no zoning, 2) 2 zones at a time, 3) 2 zones at 60% fan speed,
and 4) zoning each zone individually.
[0105] FIG. 7 though FIG. 9 illustrate that the systems and methods
of the present description can improve system energy efficiency by
20-300% (vs. single-zone) depending upon the design of the duct
system (R-value and layout), and the temperature conditions in the
duct zone.
[0106] Testing also showed that grille capacity is impacted
non-uniformly, sometimes resulting in negative capacities at
grilles, thereby reducing comfort.
[0107] In one embodiment, the up to 300% energy savings may be
driven by delivery efficiency improvements (see 40%-capacity plot
in FIG. 9). In addition, modeling shows a dramatic improvement in
grille temperature uniformity relative to single-zone
operation.
[0108] It is also appreciated that the technology of the present
description also improves thermal comfort, as it maintains the
design capacity at each grille 25, thereby maintaining the designed
thermal balance of the system at reduced capacity, which is not the
case when the entire duct system is utilized with reduced
heating/cooling capacity.
[0109] Embodiments of the present technology may be described
herein with reference to flowchart illustrations of methods and
systems according to embodiments of the technology, and/or
procedures, algorithms, steps, operations, formulae, or other
computational depictions, which may also be implemented as computer
program products. In this regard, each block or step of a
flowchart, and combinations of blocks (and/or steps) in a
flowchart, as well as any procedure, algorithm, step, operation,
formula, or computational depiction can be implemented by various
means, such as hardware, firmware, and/or software including one or
more computer program instructions embodied in computer-readable
program code. As will be appreciated, any such computer program
instructions may be executed by one or more computer processors,
including without limitation a general-purpose computer or special
purpose computer, or other programmable processing apparatus to
produce a machine, such that the computer program instructions
which execute on the computer processor(s) or other programmable
processing apparatus create means for implementing the function(s)
specified.
[0110] Accordingly, blocks of the flowcharts, and procedures,
algorithms, steps, operations, formulae, or computational
depictions described herein support combinations of means for
performing the specified function(s), combinations of steps for
performing the specified function(s), and computer program
instructions, such as embodied in computer-readable program code
logic means, for performing the specified function(s). It will also
be understood that each block of the flowchart illustrations, as
well as any procedures, algorithms, steps, operations, formulae, or
computational depictions and combinations thereof described herein,
can be implemented by special purpose hardware-based computer
systems which perform the specified function(s) or step(s), or
combinations of special purpose hardware and computer-readable
program code.
[0111] Furthermore, these computer program instructions, such as
embodied in computer-readable program code, may also be stored in
one or more computer-readable memory or memory devices that can
direct a computer processor or other programmable processing
apparatus to function in a particular manner, such that the
instructions stored in the computer-readable memory or memory
devices produce an article of manufacture including instruction
means which implement the function specified in the block(s) of the
flowchart(s). The computer program instructions may also be
executed by a computer processor or other programmable processing
apparatus to cause a series of operational steps to be performed on
the computer processor or other programmable processing apparatus
to produce a computer-implemented process such that the
instructions which execute on the computer processor or other
programmable processing apparatus provide steps for implementing
the functions specified in the block(s) of the flowchart(s),
procedure (s) algorithm(s), step(s), operation(s), formula(e), or
computational depiction(s).
[0112] It will further be appreciated that the terms "programming"
or "program executable" as used herein refer to one or more
instructions that can be executed by one or more computer
processors to perform one or more functions as described herein.
The instructions can be embodied in software, in firmware, or in a
combination of software and firmware. The instructions can be
stored local to the device in non-transitory media, or can be
stored remotely such as on a server, or all or a portion of the
instructions can be stored locally and remotely. Instructions
stored remotely can be downloaded (pushed) to the device by user
initiation, or automatically based on one or more factors.
[0113] It will further be appreciated that as used herein, that the
terms processor, hardware processor, computer processor, central
processing unit (CPU), and computer are used synonymously to denote
a device capable of executing the instructions and communicating
with input/output interfaces and/or peripheral devices, and that
the terms processor, hardware processor, computer processor, CPU,
and computer are intended to encompass single or multiple devices,
single core and multicore devices, and variations thereof.
[0114] From the description herein, it will be appreciated that the
present disclosure encompasses multiple embodiments which include,
but are not limited to, the following:
[0115] 1. An apparatus for optimizing system efficiency and demand
response performance of an air-handling system, the air-handling
system comprising a duct system having a plurality of duct sections
and one or more dampers for controlling distribution of air into
the plurality of duct sections, the apparatus comprising: (a) a
system controller coupled to the one or more dampers; and (b) said
system controller comprising a processor and a non-transitory
memory storing instructions executable on the processor to perform
steps comprising: (i) acquiring one or more operational parameters
associated with the air-handling system; (ii) selectively
controlling the one or more dampers based on the one or more
operational parameters such that that airflow is only directed
through selected duct sections of the one or more duct sections and
not through the entire duct system simultaneously; and (iii)
maintaining one or more of design velocity, heating capacity, and
cooling capacity in each duct section in which airflow is directed
to optimize one or more of system efficiency and demand response
performance of the air-handling system.
[0116] 2. The apparatus or method of any preceding or subsequent
embodiment, wherein the air handling system further comprises a
compressor or burner for conditioning the airflow and a fan for
distributing airflow into the one or more duct sections, and each
of the one or more duct sections corresponds with a zone to be
conditioned: wherein maintaining one or more of design velocity,
heating capacity, and cooling capacity in each duct section
comprises adjusting one or more of a speed of the fan and a speed
of the compressor or burner to a fraction of a 100% operation flow
represented by a zone when only one zone is being called for
conditioning or to a fraction of the 100% operation flow
represented by a sum of all zones being called for
conditioning.
[0117] 3. The apparatus or method of any preceding or subsequent
embodiment: wherein the one or more operational parameters comprise
a call for capacity reduction from the air-handling unit or a
utility supplying power to the air-handling unit; and wherein
selectively controlling one or more dampers comprises determining
if the capacity reduction that is called for is less than a sum of
a capacity of two or more zones presently being called for
conditioning, and cycling the airflow to the duct sections
corresponding to the two or more zones such that only one of the
two or more zones is receiving distributed airflow at any given
time during the call for capacity reduction.
[0118] 4. The apparatus or method of any preceding or subsequent
embodiment, wherein three zones are being called for conditioning,
and wherein cycling the airflow to the duct sections comprises:
controlling the one or more dampers such that airflow is delivered
to a first duct section corresponding to a first zone while airflow
is restricted to second and third duct sections for a first period
of time, airflow is delivered to a second duct section
corresponding to a second zone while airflow is restricted to first
and third duct sections for a second period of time, and airflow is
delivered to a third duct section corresponding to a third zone
while airflow is restricted to first and second and third duct
sections for a third period of time.
[0119] 5. The apparatus or method of any preceding or subsequent
embodiment: wherein the one or more operational parameters
comprises one or more temperature readings from sensors located
within the air-handling system and coupled to the controller;
wherein cycling of the airflow to the duct sections is only
performed if a temperature effect threshold is not met, the
temperature effect threshold being a function of the one or more
temperature readings.
[0120] 6. The apparatus or method of any preceding or subsequent
embodiment, wherein the temperature effect threshold is a function
of one or more of measured temperatures from sensors located in the
one or more ducts, a predicted duct-zone temperature, or a duct
R-value.
[0121] 7. The apparatus or method of any preceding or subsequent
embodiment, wherein the temperature effect threshold is a function
of one or more of a measured temperature variation through a duct
section, a measured temperature variation between a supply plenum
and a return plenum of the duct system, or a temperature at one or
more the grilles distributing airflow from the one or more duct
sections.
[0122] 8. The apparatus or method of any preceding or subsequent
embodiment, wherein the capacity of two or more zones is selected
from the group consisting of: compressor or burner speed, fan
speed, cooling capacity, or heating capacity.
[0123] 9. The apparatus or method of any preceding or subsequent
embodiment, wherein the capacity of two or more zones is selected
from the group consisting of: duct-section air flow, zone air flow,
duct-inlet temperature, duct-outlet temperature, and duct-zone
temperature.
[0124] 10. The apparatus or method of any preceding or subsequent
embodiment, further comprising: manipulating fan speed so as to
decrease fan speed less than a specified decrease in compressor or
burner speed or decrease in system capacity associated with the
call for capacity reduction.
[0125] 11. A method for optimizing system efficiency and demand
response performance of an air-handling system the air-handling
system comprising a duct system having a plurality of duct sections
and one or more dampers for controlling distribution of air into
the plurality of duct sections, the method comprising: acquiring
one or more operational parameters associated with the air-handling
system; selectively controlling the one or more dampers based on
the one or more operational parameters such that that airflow is
only directed through selected duct sections of the one or more
duct sections and not through the entire duct system
simultaneously; and maintaining one or more of design velocity,
heating capacity, and cooling capacity in each duct section in
which airflow is directed to optimize one or more of system
efficiency and demand response performance of the air-handling
system; wherein said method is performed by a processor executing
instructions stored on a non-transitory medium.
[0126] 12. The apparatus or method of any preceding or subsequent
embodiment, wherein the air handling system further comprises a
compressor or burner for conditioning the airflow and a fan for
distributing airflow into the one or more duct sections, and each
of the one or more duct sections corresponds with a zone to be
conditioned: wherein maintaining one or more of design velocity,
heating capacity, and cooling capacity in each duct section
comprises adjusting one or more of a speed of the fan and a speed
of the compressor or burner to a fraction of a 100% operation flow
represented by a zone when only one zone is being called for
conditioning or to a fraction of the 100% operation flow
represented by a sum of all zones being called for
conditioning.
[0127] 13. The apparatus or method of any preceding or subsequent
embodiment: wherein the one or more operational parameters comprise
a call for capacity reduction from the air-handling unit or a
utility supplying power to the air-handling unit; and wherein
selectively controlling one or more dampers comprises determining
if the capacity reduction that is called for is less than a sum of
a capacity of two or more zones presently being called for
conditioning, and cycling the airflow to the duct sections
corresponding to the two or more zones such that only one of the
two or more zones is receiving distributed airflow at any given
time during the call for capacity reduction.
[0128] 14. The apparatus or method of any preceding or subsequent
embodiment, wherein three zones are being called for conditioning,
and wherein cycling the airflow to the duct sections comprises:
controlling the one or more dampers such that airflow is delivered
to a first duct section corresponding to a first zone while airflow
is restricted to second and third duct sections for a first period
of time, airflow is delivered to a second duct section
corresponding to a second zone while airflow is restricted to first
and third duct sections for a second period of time, and airflow is
delivered to a third duct section corresponding to a third zone
while airflow is restricted to first and second and third duct
sections for a third period of time.
[0129] 15. The apparatus or method of any preceding or subsequent
embodiment: wherein the one or more operational parameters
comprises one or more temperature readings within the air-handling
system; wherein cycling of the airflow to the duct sections is only
performed if a temperature effect threshold is not met, the
temperature effect threshold being a function of the one or more
temperature readings.
[0130] 16. The apparatus or method of any preceding or subsequent
embodiment, wherein the temperature effect threshold is a function
of one or more of measured temperatures from sensors located in the
one or more ducts, a predicted duct-zone temperature, or a duct
R-value.
[0131] 17. The apparatus or method of any preceding or subsequent
embodiment, wherein the temperature effect threshold is a function
of one or more of a measured temperature variation through a duct
section, a measured temperature variation between a supply plenum
and a return plenum of the duct system, or a temperature at one or
more the grilles distributing airflow from the one or more duct
sections.
[0132] 18. The apparatus or method of any preceding or subsequent
embodiment, wherein the capacity of two or more zones is selected
from the group consisting of: compressor or burner speed, fan
speed, cooling capacity, or heating capacity.
[0133] 19. The apparatus or method of any preceding or subsequent
embodiment, wherein the capacity of two or more zones is selected
from the group consisting of: duct-section air flow, zone air flow,
duct-inlet temperature, duct-outlet temperature, and duct-zone
temperature.
[0134] 20. The apparatus or method of any preceding or subsequent
embodiment, further comprising: manipulating fan speed so as to
decrease fan speed less than a specified decrease in compressor or
burner speed or decrease in system capacity associated with the
call for capacity reduction.
[0135] 21. An air-handling system optimized for efficiency and
demand response performance, comprising: (a) an air-handling unit;
(b) a duct system coupled to the air handling unit, the duct system
comprising a plurality of duct sections and one or more dampers for
controlling distribution of air into the plurality of duct
sections, the apparatus comprising: (c) a system controller coupled
to the one or more dampers and air handling unit; and (d) said
system controller comprising a processor and a non-transitory
memory storing instructions executable on the processor to perform
steps comprising: (i) acquiring one or more operational parameters
associated with the air-handling system; (ii) selectively
controlling the one or more dampers based on the one or more
operational parameters such that that airflow is only directed
through selected duct sections of the one or more duct sections and
not through the entire duct system simultaneously; and (iii)
maintaining one or more of design velocity, heating capacity, and
cooling capacity in each duct section in which airflow is directed
to optimize one or more of system efficiency and demand response
performance of the air-handling system.
[0136] 22. The apparatus or method of any preceding or subsequent
embodiment, wherein the air handling unit further comprises a
compressor or burner for conditioning the airflow and a fan for
distributing airflow into the one or more duct sections, and each
of the one or more duct sections corresponds with a zone to be
conditioned: wherein maintaining one or more of design velocity,
heating capacity, and cooling capacity in each duct section
comprises adjusting one or more of a speed of the fan and a speed
of the compressor or burner to a fraction of a 100% operation flow
represented by a zone when only one zone is being called for
conditioning or to a fraction of the 100% operation flow
represented by a sum of all zones being called for
conditioning.
[0137] 23. The apparatus or method of any preceding or subsequent
embodiment: wherein the one or more operational parameters comprise
a call for capacity reduction from the air-handling unit or a
utility supplying power to the air-handling unit; and wherein
selectively controlling one or more dampers comprises determining
if the capacity reduction that is called for is less than a sum of
a capacity of two or more zones presently being called for
conditioning, and cycling the airflow to the duct sections
corresponding to the two or more zones such that only one of the
two or more zones is receiving distributed airflow at any given
time during the call for capacity reduction.
[0138] 24. The apparatus or method of any preceding or subsequent
embodiment, wherein three zones are being called for conditioning,
and wherein cycling the airflow to the duct sections comprises:
controlling the one or more dampers such that airflow is delivered
to a first duct section corresponding to a first zone while airflow
is restricted to second and third duct sections for a first period
of time, airflow is delivered to a second duct section
corresponding to a second zone while airflow is restricted to first
and third duct sections for a second period of time, and airflow is
delivered to a third duct section corresponding to a third zone
while airflow is restricted to first and second and third duct
sections for a third period of time.
[0139] 25. The apparatus or method of any preceding or subsequent
embodiment, further comprising one or more sensors located within
the air handling system and coupled to the system controller:
wherein the one or more operational parameters comprises one or
more temperature readings from the one or more sensors within the
air-handling system; wherein cycling of the airflow to the duct
sections is only performed if a temperature effect threshold is not
met, the temperature effect threshold being a function of the one
or more temperature readings.
[0140] 26. The apparatus or method of any preceding or subsequent
embodiment, wherein the temperature effect threshold is a function
of one or more of measured temperatures from sensors located in the
one or more ducts, a predicted duct-zone temperature, or a duct
R-value.
[0141] 27. The apparatus or method of any preceding or subsequent
embodiment, wherein the temperature effect threshold is a function
of one or more of a measured temperature variation through a duct
section, a measured temperature variation between a supply plenum
and a return plenum of the duct system, or a temperature at one or
more the grilles distributing airflow from the one or more duct
sections.
[0142] 28. The apparatus or method of any preceding or subsequent
embodiment, wherein the capacity of two or more zones is selected
from the group consisting of: compressor or burner speed, fan
speed, cooling capacity, or heating capacity.
[0143] 29. The apparatus or method of any preceding or subsequent
embodiment, wherein the capacity of two or more zones is selected
from the group consisting of: duct-section air flow, zone air flow,
duct-inlet temperature, duct-outlet temperature, and duct-zone
temperature.
[0144] 30. The apparatus or method of any preceding or subsequent
embodiment, further comprising: manipulating fan speed so as to
decrease fan speed less than a specified decrease in compressor or
burner speed or decrease in system capacity associated with the
call for capacity reduction.
[0145] 31. A method for optimizing system efficiency and demand
response performance for variable-fan-speed and variable-capacity
air handling systems, the method comprising: (a) sensing system
operational parameters selected from the group consisting of
compressor speed, cooling capacity, heating capacity, fan speed,
duct-section air flow, zone air flow, duct-inlet temperature,
duct-outlet temperature, and duct-zone temperature; (b) selectively
controlling building-zone dampers such that air flows through
selected duct sections and not through the entire duct system
simultaneously, wherein design velocity in each duct section is
roughly maintained whenever the duct section is being used; (c)
using measured or predicted duct-zone temperature, duct R-value,
and optionally duct-system layout, to determine when to flow air
through a duct section in step (b); and (d) optionally decreasing
indoor fan speed less than the desired decrease in compressor speed
or system capacity; (e) wherein said method is performed by a
system controller.
[0146] 32. The apparatus or method of any preceding or subsequent
embodiment, wherein said system controller comprises a processor
and a non-transitory memory storing instructions executable by the
processor to perform said method.
[0147] 33. The apparatus or method of any preceding or subsequent
embodiment, wherein said selectively controlling building-zone
dampers such that air flows through selected duct sections
comprises cycling the building-zone dampers between open and closed
positions sequentially through all said zones calling for
conditioning.
[0148] 34. A system for optimizing system efficiency and demand
response performance for variable-fan-speed and variable-capacity
furnace, heat pump, and air conditioning systems, the system
comprising: (a) a system controller; and (b) a plurality of
sensors; (c) wherein said system controller and said sensors are
configured to perform steps comprising: (I) sensing system
operational parameters selected from the group consisting of
compressor speed, cooling capacity, heating capacity, fan speed,
duct-section air flow, zone air flow, duct-inlet temperature,
duct-outlet temperature, and duct-zone temperature; (ii)
selectively controlling building-zone dampers such that air flows
through selected duct sections and not through the entire duct
system simultaneously, wherein design velocity in each duct section
is roughly maintained whenever the duct section is being used;
(iii) using measured or predicted duct-zone temperature, duct
R-value, and optionally duct-system layout, to determine when to
flow air through a duct section in step (b); and (iv) optionally
decreasing indoor fan speed less than the desired decrease in
compressor speed or system capacity.
[0149] 35. The apparatus or method of any preceding or subsequent
embodiment, wherein said system controller comprises: a processor;
and a non-transitory memory storing instructions executable by the
processor.
[0150] 36. The apparatus or method of any preceding or subsequent
embodiment, wherein said selectively controlling building-zone
dampers such that air flows through selected duct sections
comprises cycling the building-zone dampers between open and closed
positions sequentially through all said zones calling for
conditioning.
[0151] As used herein, the singular terms "a," "an," and "the" may
include plural referents unless the context clearly dictates
otherwise. Reference to an object in the singular is not intended
to mean "one and only one" unless explicitly so stated, but rather
"one or more."
[0152] As used herein, the term "set" refers to a collection of one
or more objects. Thus, for example, a set of objects can include a
single object or multiple objects.
[0153] As used herein, the terms "substantially" and "about" are
used to describe and account for small variations. When used in
conjunction with an event or circumstance, the terms can refer to
instances in which the event or circumstance occurs precisely as
well as instances in which the event or circumstance occurs to a
close approximation. When used in conjunction with a numerical
value, the terms can refer to a range of variation of less than or
equal to .+-.10% of that numerical value, such as less than or
equal to .+-.5%, less than or equal to .+-.4%, less than or equal
to .+-.3%, less than or equal to .+-.2%, less than or equal to
.+-.1%, less than or equal to .+-.0.5%, less than or equal to
.+-.0.1%, or less than or equal to .+-.0.05%. For example,
"substantially" aligned can refer to a range of angular variation
of less than or equal to .+-.10.degree., such as less than or equal
to .+-.5.degree., less than or equal to .+-.4.degree., less than or
equal to .+-.3.degree., less than or equal to .+-.2.degree., less
than or equal to .+-.1.degree., less than or equal to
.+-.0.5.degree., less than or equal to .+-.0.1.degree., or less
than or equal to .+-.0.05.degree..
[0154] Additionally, amounts, ratios, and other numerical values
may sometimes be presented herein in a range format. It is to be
understood that such range format is used for convenience and
brevity and should be understood flexibly to include numerical
values explicitly specified as limits of a range, but also to
include all individual numerical values or sub-ranges encompassed
within that range as if each numerical value and sub-range is
explicitly specified. For example, a ratio in the range of about 1
to about 200 should be understood to include the explicitly recited
limits of about 1 and about 200, but also to include individual
ratios such as about 2, about 3, and about 4, and sub-ranges such
as about 10 to about 50, about 20 to about 100, and so forth.
[0155] Although the description herein contains many details, these
should not be construed as limiting the scope of the disclosure but
as merely providing illustrations of some of the presently
preferred embodiments. Therefore, it will be appreciated that the
scope of the disclosure fully encompasses other embodiments which
may become obvious to those skilled in the art.
[0156] All structural and functional equivalents to the elements of
the disclosed embodiments that are known to those of ordinary skill
in the art are expressly incorporated herein by reference and are
intended to be encompassed by the present claims. Furthermore, no
element, component, or method step in the present disclosure is
intended to be dedicated to the public regardless of whether the
element, component, or method step is explicitly recited in the
claims. No claim element herein is to be construed as a "means plus
function" element unless the element is expressly recited using the
phrase "means for". No claim element herein is to be construed as a
"step plus function" element unless the element is expressly
recited using the phrase "step for".
* * * * *