U.S. patent application number 12/906352 was filed with the patent office on 2011-04-21 for vacuum and freeze-up hvac sensor.
This patent application is currently assigned to CoreRed, LLC. Invention is credited to Cornelius Z. Koethler.
Application Number | 20110088416 12/906352 |
Document ID | / |
Family ID | 43878245 |
Filed Date | 2011-04-21 |
United States Patent
Application |
20110088416 |
Kind Code |
A1 |
Koethler; Cornelius Z. |
April 21, 2011 |
Vacuum And Freeze-Up HVAC Sensor
Abstract
An apparatus for monitoring an HVAC system. The apparatus
comprises a freeze-up sensor, a vacuum sensor, and a thermostat.
The freeze-up sensor communicates a signal to indicate that ice is
developing in the HVAC system and the vacuum sensor communicates a
signal to indicate that a vacuum pressure exists in the HVAC
system. When a signal is detected, the apparatus deactivates the
HVAC system to prevent damage. The thermostat comprises a
touch-screen display with a continuous set-point.
Inventors: |
Koethler; Cornelius Z.;
(Seminole, TX) |
Assignee: |
CoreRed, LLC
Seminole
TX
|
Family ID: |
43878245 |
Appl. No.: |
12/906352 |
Filed: |
October 18, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61252249 |
Oct 16, 2009 |
|
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Current U.S.
Class: |
62/80 ; 62/150;
62/207 |
Current CPC
Class: |
F24F 11/30 20180101;
F24F 2110/40 20180101; F24F 11/32 20180101 |
Class at
Publication: |
62/80 ; 62/207;
62/150 |
International
Class: |
F25D 21/02 20060101
F25D021/02; F25B 41/00 20060101 F25B041/00; F25D 21/00 20060101
F25D021/00 |
Claims
1. An apparatus for monitoring a HVAC system, the HVAC system
comprising a thermostat, a condensing unit, a compressor, an
evaporator coil, and a filter, the apparatus comprising: a
freeze-up sensor located proximate the evaporator coil such that
when the sensor detects a threshold temperature the sensor
transmits a freeze-up signal; a receiver for receiving the
freeze-up signal; a switch operatively connected to the HVAC system
and the receiver to disable the compressor and condensing unit
after the freeze-up signal is received by the receiver; an
indicator located proximate the thermostat indicating receipt of
the freeze-up signal by the receiver.
2. The apparatus of claim 1 further comprising a vacuum sensor
located proximate the filter to detect a threshold vacuum pressure
and transmit a vacuum signal to the receiver upon detection of a
vacuum pressure at or exceeding the threshold vacuum pressure.
3. The apparatus of claim 2 further comprising a screen located
proximate the thermostat comprising: a touch screen display; the
indicator; and a continuous setpoint graph located at and
adjustable on the touch screen display for creating a continuous
temperature setpoint.
4. The apparatus of claim 1 wherein the threshold temperature is
less than 35 degrees Fahrenheit.
5. The apparatus of claim 1 wherein the freeze-up sensor is adapted
to detect condensation proximate the evaporator coil.
6. An apparatus for monitoring a HVAC system, the HVAC system
comprising a thermostat, a condensing unit, a compressor, an
evaporator coil, and a filter, the apparatus comprising: a
freeze-up sensor located proximate the evaporator coil such that
when the sensor detects a threshold temperature and condensation
proximate the evaporator coil the freeze-up sensor transmits a
freeze-up signal; a vacuum sensor located proximate the filter to
transmit a vacuum signal upon detection of a vacuum pressure at or
exceeding a threshold vacuum pressure; a receiver for receiving the
freeze-up signal and the vacuum signal; a switch to disable the
compressor and condensing unit after the receiver receives the
freeze-up signal or the vacuum signal; and an indicator located
proximate the thermostat indicating the switch has disabled the
compressor and condensing unit.
7. The apparatus of claim 6 wherein the receiver is proximate the
thermostat.
8. The apparatus of claim 6 wherein the receiver comprises a sensor
monitor.
9. The apparatus of claim 6 wherein the indicator indicates whether
the freeze-up signal or the vacuum signal occurred first.
10. A method for monitoring an HVAC system, the HVAC system
comprising a thermostat, a condensing unit, a compressor, an
evaporator coil, and a filter, the method comprising: detecting a
threshold temperature and condensation proximate the evaporator
coil; transmitting a freeze-up signal after detection of the
threshold temperature and condensation proximate the evaporator
coil; receiving the freeze-up signal at a receiver; transmitting a
shut-down signal to the compressor and condensing unit upon receipt
of the freeze-up signal at the receiver; ceasing operation of the
compressor and condensing unit after receiving the freeze-up
signal; and resuming operation of the compressor and condensing
unit when the freeze-up signal is no longer received by the
receiver.
11. The method of claim 10 further comprising transmitting a vacuum
signal when the vacuum sensor indicates a vacuum pressure at or
exceeding a threshold vacuum pressure proximate the filter.
12. The method of claim 11 further comprising adjusting the
threshold vacuum pressure at which the vacuum-sensor transmits a
vacuum signal.
13. The method of claim 11 further comprising detecting which of
the vacuum signal and the freeze-up signal was transmitted
first.
14. The method of claim 13 further comprising replacing the filter
if the vacuum signal was transmitted prior to the freeze-up
signal.
15. The method of claim 10 further comprising setting a continuous
temperature setpoint at the thermostat.
16. A thermostat for use with an HVAC system comprising a filter,
the thermostat comprising: a touch screen display; a freeze-up
indicator located on the touch screen display and operatively
connected to a freeze-up sensor; a vacuum indicator located on the
touch screen display and operatively connected to a vacuum sensor;
wherein the freeze-up indicator indicates the HVAC system is not
operating due to a low temperature and condensation in the HVAC
system and the vacuum sensor indicates the HVAC system is not
operating due to a vacuum pressure at or exceeding a threshold
pressure in the HVAC system; and a continuous setpoint graph
located at and adjustable on the touch screen display for creating
a continuous temperature setpoint.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/252,249 filed Oct. 16, 2009, the contents of
which are incorporated fully herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to thermostats and air
conditioning units, and particularly to systems for monitoring the
condition of the air conditioning units and preventing system
failure.
SUMMARY OF THE INVENTION
[0003] The present invention is directed to an apparatus for
monitoring a Heating, Ventilation, and Air Conditioning (HVAC)
system. The HVAC system comprises a thermostat, a condensing unit,
an evaporator coil, and a filter. The system comprises a freeze-up
sensor, a receiver, a switch, and an indicator. The freeze-up
sensor is located proximate the evaporator coil such that when the
sensor detects a threshold temperature the sensor transmits a
freeze-up signal. The receiver is for receiving the freeze-up
signal. The switch is operatively connected to the HVAC system to
disable the compressor and condensing unit after the freeze-up
signal is received by the receiver. The indicator is located
proximate the thermostat indicating receipt of the freeze-up signal
by the receiver.
[0004] Another embodiment of the invention is directed to an
apparatus for monitoring an HVAC system. The HVAC system comprises
a thermostat, a condensing unit, an evaporator coil, and a filter.
The apparatus comprises a freeze-up sensor located proximate the
evaporator coil such that when the sensor detects a threshold
temperature and condensation the freeze-up sensor transmits a
freeze-up signal, a vacuum sensor located proximate the filter to
transmit a vacuum signal upon detection of a vacuum pressure at or
exceeding a threshold vacuum pressure, a receiver for receiving the
freeze-up signal and the vacuum signal, a switch to disable the
compressor and condensing unit after the receiver is receives the
freeze-up signal or the vacuum signal, and an indicator located
proximate the thermostat indicating the switch has disabled the
compressor and condensing unit.
[0005] Still another embodiment of the invention is directed to a
method for monitoring an HVAC system. The HVAC system comprises a
thermostat, a condensing unit, a compressor, an evaporator coil,
and a filter. The method comprises detecting a threshold
temperature and condensation proximate the evaporator coil,
transmitting a freeze-up signal after detection of the threshold
temperature and condensation proximate the evaporator coil,
receiving the freeze-up signal at a receiver, transmitting a
shut-down signal to the compressor and condensing unit upon receipt
of the freeze-up signal at the receiver, ceasing operation of the
compressor and condensing unit after receiving the freeze-up
signal, resuming operation of the compressor and condensing unit
when the freeze-up signal is no longer received by the
receiver.
[0006] Another embodiment is directed to a thermostat for use with
an HVAC system comprising a filter. The thermostat comprises a
touch screen display, a freeze-up sensor indicator located on the
touch screen display and operatively connected to an freeze-up
sensor, a vacuum sensor indicator located on the touch screen
display and operatively connected to a vacuum sensor; wherein the
freeze-up sensor indicator indicates the HVAC system is not
operating due to a low temperature and condensation in the HVAC
system and the vacuum sensor indicates the HVAC system is not
operating due to a vacuum pressure in the HVAC system, and a
continuous setpoint graph located at and adjustable on the touch
screen display for creating a continuous temperature setpoint.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is diagrammatic representation of an HVAC system for
use with the apparatus for monitoring an HVAC system in accordance
with the present invention.
[0008] FIG. 2 is diagrammatic representation of an inside unit and
an apparatus for monitoring an HVAC system.
[0009] FIG. 3 is a diagrammatic representation of an outside unit
and the apparatus for monitoring the HVAC system of FIG. 1.
[0010] FIG. 4 is a diagrammatic representation of a thermostat and
thermostat display for use with an apparatus for monitoring the
HVAC system of FIG. 1.
DETAILED DESCRIPTION OF THE DRAWINGS
[0011] Air conditioners, or HVAC systems, suffer from two problems
which are addressed by the present invention. First, ice formation
within an HVAC system causes multiple problems, including
overheating a blower motor and pumping liquid Freon through the
unit's compressor. Further, ice build-up can cause the HVAC system
to operate at reduced efficiency. Second, clogged return air
filters will restrict the flow of air into the HVAC system, which
will cause the blower motor to work at a lower efficiency and limit
the life of the motor. The present invention seeks to eliminate
these two problems by utilizing sensors with a monitor in a system
that can be read and operated by both owners and technicians.
Further, the present invention allows limited operation of an HVAC
system under ice build-up conditions to enable a building to be
cooled when, for instance, occupants are away. Finally, ice
build-up conditions can lead to a vacuum reading within an HVAC
system and a clogged filter may lead to mild ice-up conditions.
Therefore, there is a need for a thermostat which notes the first
condition to arise so that an occupant or technician can know the
origination of the problem with the HVAC system.
[0012] Turning to the drawings in general and FIG. 1 in particular,
shown therein is an HVAC system 12. The HVAC system 12 comprises an
outside unit 24 and an inside unit 26. The outside unit 24 may
comprise a condenser 16 and a compressor 18. The outside unit 24 is
generally located outside of a building, and is the equipment one
thinks of when considering an air conditioner. The compressor 18
compresses refrigerant received from the inside unit 26 to raise
its density and raise its temperature. The condenser 16 then uses
the outside air to cool the dense refrigerant, often using a large
fan (not shown) within the outside unit, condensing the pressurized
vapor to a fluid. The inside unit 26 comprises a blower 20, an
evaporator coil 14, and a filter 28. The filter 28 is adapted to
remove dust and other impurities from air within a building. The
blower 20 operates to move warm air from a building through the
filter 28 and across the evaporator coil 14. The evaporator coil 14
is the primary heat exchange used for cooling a building. The
evaporator coil 14 expands the condensed refrigerant fluid, causing
the temperature to drop. The temperature of the coil 14 thus allows
the air pushed across the coil by the blower 20 to cool. The
thermostat 22 is operatively connected to the HVAC system 12 by a
connection system 29 and may be located remote from the inside unit
24 and outside unit 26, at a location inside a building where a
temperature set point can be initiated.
[0013] As shown by directional arrows in FIG. 1, the blower 20
causes air to be forced into the inside unit 26 through the filter
28. The air is forced past the evaporator coil 14, cooled, and
returned to the building.
[0014] With reference now to FIG. 2, the inside unit 26 of the
present invention is shown. The inside unit 26 comprises a
freeze-up sensor 30, a vacuum sensor 32, and a sensor monitor 34.
The freeze-up sensor 30 is positioned proximate the evaporator coil
14 and adapted to determine whether an air temperature within the
inside unit 26 proximate the evaporator coil is near a threshold
temperature. The freeze-up sensor 30 may comprise an electronic or
mechanical sensor capable of detecting air temperature. Preferably,
the freeze-up sensor 30 is capable of detecting both an air
temperature and condensation. When the freeze-up sensor 30 detects
a threshold temperature near freezing, it sends a freeze-up signal
to the sensor monitor 34. Preferably, the freeze-up sensor 30 sends
the freeze-up signal to the sensor Monitor 34 when a temperature
below 35 degrees Fahrenheit is detected and more preferably when a
temperature below 30 degrees Fahrenheit is detected. One freeze-up
sensor 30 which may be used is a cooling coil temperature sensor
having a temperature sensitivity of two degrees Celsius.
[0015] The vacuum sensor 32 is adapted to detect a vacuum pressure
within the HVAC system 10. A vacuum pressure in excess of a
threshold pressure can cause the blower 20 to work harder and
ultimately fail. The vacuum sensor 32 is adapted to transmit a
vacuum signal to the sensor monitor 34 when the threshold pressure
is reached. Preferably, the threshold pressure at which the vacuum
sensor transmits the vacuum signal is adjustable. The vacuum sensor
32 may be any one of a number of commercially available pressure
sensors. One particular vacuum sensor 32 that can be used is an
external fan box differential pressure sensor, having a 2 inHg
pressure range, though other sensors can be used. As shown in FIG.
2, the vacuum sensor 32 is located proximate the filter 28.
[0016] Continuing with FIG. 2, the freeze-up sensor 30 and the
vacuum sensor 32 are operatively connected to the sensor monitor 34
such that the sensor monitor can detect whether the freeze-up
sensor 30 is transmitting a freeze-up signal and/or the vacuum
sensor 32 is transmitting a vacuum signal. The sensor monitor 34
transmits an indicator signal to an indicators 36a and 36b located
proximate the thermostat 22. In the embodiment shown in FIG. 2, the
indicators 36a and 36b comprise a vacuum monitor light 36a, and a
freeze-up monitor light 36b. The vacuum monitor light 36a is
illuminated when the vacuum sensor 32 is transmitting a vacuum
signal, and the freeze-up monitor light 36b is illuminated when the
freeze-up sensor 30 is transmitting the freeze-up signal.
[0017] In a preferred embodiment, the sensor monitor 34 further
comprises a processor (not shown) programmed to determine which of
the freeze-up monitor light 36a and the vacuum monitor light 36b
was activated first. The processor may activate an additional
light, or a setting recorded in the memory of the sensor monitor 34
or the indicator 36. Thus, a technician or occupant could determine
the cause of problems with the HVAC system 12 and more efficiently
address the problem.
[0018] With reference to FIG. 3, the HVAC system 12 may further
comprise a switch 50 operatively connected to the sensor monitor 34
and to the outside unit 24. The switch 50 is usually open, such
that in normal operation of the HVAC system 12, components of the
outside unit 24 such as the compressor 18 and condenser 16 operate
normally. However, when the sensor monitor 34 receives the
freeze-up signal or the vacuum signal, the switch 50 closes,
causing the condenser 16 and compressor 18 to shut off, preventing
damage to the HVAC system 12. When the sensor monitor 34 no longer
receives the freeze-up signal or the vacuum signal, the switch 50
re-opens, allowing some limited non-destructive operation of the
HVAC system 12 even when a defective condition may still exist. The
indicators 36a or 36b located at thermostat 22 (FIG. 2) indicate
whether the switch 50 has deactivated the compressor 18 and
condenser 16.
[0019] The thermostat 22 may be any of a number of commercially
available thermostats, and adapted for use with the indicators 36a
and 36b of the apparatus 10. With reference now to FIG. 4, an
improved embodiment of the thermostat 22 for use in the present
invention is shown in more detail. The thermostat 22 comprises a
chassis 101 to support a touch screen display 100. Preferably, the
touch screen display 100 is a resistive interface compatible with a
finger and/or stylus (not shown). The touch screen display 100
comprises a continuous setpoint graph 102 for programming a
temperature. The continuous setpoint graph 102 is adjustable on the
touch screen display 100 and may be used to create a continuous
temperature setpoint for operation of the HVAC system 12 over an
extended period of time. Multiple functions of the thermostat 22
and HVAC system 12 may be adjusted at the touch screen display 100,
such as the time, threshold temperature for the freeze-up sensor 30
(FIG. 2), threshold pressure for the vacuum sensor 32 (FIG. 2), and
other operational and automated functions. Further, the thermostat
22 contains a memory device (not shown) which allows data logging
and updating of the thermostat software. The touch screen display
100 may further comprise a control interface 104 to control
operation of the HVAC system 12, an internal clock, the blower fan
20 (FIG. 1), and settings such as Fahrenheit reading vs. Celsius
reading and display language. Additionally, the thermostat 22 may
comprise a battery backup in the case of external power failure. As
shown, the indicators 36a and 36b may be integral with the
thermostat 22, and the freeze-up monitor indicator 36a and vacuum
monitor indicator 36b are located on the touch screen display
100.
[0020] In operation, the apparatus 10 is used to provide a method
for monitoring the HVAC system 12. First, the freeze-up sensor 30
detects temperature and the presence of condensation proximate the
evaporator coil 14. When the threshold temperature is detected, the
freeze-up sensor 30 transmits a freeze-up signal to the sensor
monitor 34. After receiving the freeze-up signal, a processor (not
shown) located at the thermostat 22 transmits a shutdown signal to
the compressor 18 and/or the condenser 16. Finally, operation of
the compressor 18 and condenser 16 may resume when the freeze-up
signal is no longer received by the sensor monitor 34.
[0021] The vacuum sensor 32 may also transmit a vacuum signal when
the vacuum sensor 32 indicates a threshold vacuum pressure
proximate the filter 28. The filter 28 may be replaced with a clean
filter if the filter is viewed as the cause of the problem, for
example, if the vacuum signal was transmitted prior to the
freeze-up signal. A desired vacuum pressure at which the vacuum
sensor 32 transmits the vacuum signal may be set at the thermostat
22. The thermostat 22 may also allow an occupant to set a
continuous temperature setpoint 102.
[0022] Various modifications in the design and operation of the
present invention are contemplated without departing from the
spirit of the invention. For example, the apparatus 10 and HVAC
unit 12 may be operated remotely, or through Internet access. Thus,
while the principal preferred construction and modes of operation
of the invention have been illustrated and described in what is now
considered to represent its best embodiments it should he
understood that the invention may be practiced otherwise than as
specifically illustrated and described.
* * * * *