U.S. patent application number 09/741788 was filed with the patent office on 2002-01-03 for air conditioner condensation pan overflow protection.
Invention is credited to Lea, Doris W..
Application Number | 20020000093 09/741788 |
Document ID | / |
Family ID | 26909006 |
Filed Date | 2002-01-03 |
United States Patent
Application |
20020000093 |
Kind Code |
A1 |
Lea, Doris W. |
January 3, 2002 |
Air conditioner condensation pan overflow protection
Abstract
A liquid level sensor (100) is added to air conditioner
condensation pan(s) (40 and/or 50) to prevent overflow and
subsequent house damage by turning off the compressor (80) and the
fan (20) by means of a circuit breaker (120) and associated
electronics (110).
Inventors: |
Lea, Doris W.; (Houston,
TX) |
Correspondence
Address: |
Doris W. Lea
6230 Bayou Bridge
Houston
TX
77096
US
|
Family ID: |
26909006 |
Appl. No.: |
09/741788 |
Filed: |
December 21, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60214443 |
Jun 28, 2000 |
|
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Current U.S.
Class: |
62/150 ;
62/285 |
Current CPC
Class: |
F24F 2140/30 20180101;
F24F 13/222 20130101 |
Class at
Publication: |
62/150 ;
62/285 |
International
Class: |
F25D 021/00; F25D
021/14 |
Claims
1. A method for preventing the overflow of refrigeration air
conditioner condensation pan(s), comprising: a) a liquid level
sensor in the pan or pans, and b) sensor electronic circuitry to
activate the sensor, and c) a connection between the sensor
circuitry and circuit breakers in the air conditioner compressor
and fan power lines, and d) a connection between the sensor
circuitry and an alarm, whereby a rise in the level of condensed
water in the pan or pans to a point near spillage will turn off the
compressor and fan, and activate an alarm.
2. The liquid level sensor and associated circuitry of claim 1,
used to prevent the overflow of the drain pan on evaporative air
conditioners by shutting off the water pump and activating an
alarm.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is entitled to the benefit of Provisional
Patent Application Ser. #60/214443, 2000 Jun. 28.
BACKGROUND--FIELD OF INVENTION
[0002] This invention relates to refrigeration air conditioner
condensation pans, specifically to a method of preventing the
overflow of such pans and the subsequent damage caused by such
overflow.
BACKGROUND--DESCRIPTION OF PRIOR ART
[0003] Refrigeration air conditioners for homes usually have the
cooling coils mounted in the attic. During the cooling process,
water is condensed from the air, is caught in one or more
condensation pans mounted below the cooling coils, and must be
removed by drains in the pan or pans. These drains often plug up,
and the water in the pans overflows and causes structural and
property damage to the house. This is a common occurrence. It has
happened to us twice, and to many of our friends and neighbors.
SUMMARY
[0004] In accordance with the present invention, a liquid level
sensor and associated electronics are attached to an air
conditioner condensation pan or pans, to prevent overflow by
shutting off the air conditioner fan and compressor, and optionally
sounding an alarm.
OBJECTS AND ADVANTAGES
[0005] Accordingly, several objects and advantages of my invention
are:
[0006] (a) to prevent the air conditioner condensation pan overflow
and subsequent damage to houseand property by shutting off the fan
and compressor;
[0007] (b) to prevent the air conditioner from being restarted
until the pan drain(s) is/are cleared of obstruction and the pan(s)
drain properly.
DRAWING FIGURES
[0008] FIG. 1 is a schematic drawing of the condensation pan(s)
associated with the cooling coils of a refrigeration air
conditioner, and the drains to such pans.
[0009] FIG. 2 is a schematic of the electrical wiring associated
with the refrigeration air conditioner.
[0010] FIG. 3 shows an installation of a liquid level sensor in one
condensation pan of a refrigeration air conditioner.
[0011] FIG. 4 shows one embodiment of the electronic circuitry
required to shut off the air conditioner fan and compressor.
[0012] FIG. 5 shows an alternative embodiment of the electronic
circuitry, incorporating an alarm circuit.
REFERENCE NUMERALS IN DRAWINGS
[0013] 10 cooling coils
[0014] 15 refrigerant lines
[0015] 20 fan
[0016] 25 electrical lines from thermostat to fan
[0017] 30 ductwork
[0018] 40 primary condensation pan
[0019] 45 primary condensation pan drain
[0020] 50 secondary condensation pan
[0021] 55 secondary condensation pan drain
[0022] 60 electrical lines from thermostat, fan, compressor
[0023] 70 thermostat
[0024] 80 compressor
[0025] 90 electrical lines from thermostat to compressor
[0026] 95 alternative condensation pan drain
[0027] 100 liquid level sensor
[0028] 105 wiring from liquid level sensor to sensor power supply
and trigger
[0029] 110 sensor power supply and trigger
[0030] 120 circuit breaker
[0031] 130 alarm
DESCRIPTION--FIGS. 1, 2 and 3--PREFERRED EMBODIMENT
[0032] A standard home refrigeration attic installation is shown in
FIG. 1. A compressor sends refrigeration fluid through refrigerant
lines 15 to a set of cooling coils 10 mounted in ductwork 30 in an
attic. The cooling coils have moist air blown across them by a fan
20 controlled by a thermostat 70 through wiring 25, and into the
ductwork 30. The condensed moisture from the air falls into one or
more condensation pans 40, 50 and is drained into the house sewer
or out of the house at the roofline through drains 45, 55. In some
home installations, only one pan 40, called the primary pan, is
used, while other installations use two pans 40, 50, a primary and
a secondary pan. The secondary pan is below the primary pan, and
larger, in order to catch any spillage from the primary pan.
[0033] FIG. 2 shows the standard electrical wiring associated with
a refrigeration air conditioner. A thermostat 70 in the house
senses the air temperature, and turns the compressor 80 and the fan
20 on or off as required. Power for the thermostat, fan and
compressor is furnished from the house power lines 60. The
thermostat 70 switches the compressor 80 and the fan 20 on and off
through different circuits 90, 25.
[0034] A preferred embodiment of the present invention is shown in
FIG. 3. A liquid level sensor 100 is attached to the inside of each
existing condensation pan 45, 55. The liquid level sensor has its
associated electronics 110 consisting of a power supply and a
triggering mechanism connected to a circuit breaker 120 in the main
leg of the power line leading to the compressor 80 and the fan 20.
The circuit breaker 120 remains closed until the liquid level
sensor 100 senses that water is about to spill from one or both
pans. At that point, the triggering electronics 110 will open the
circuit breaker 120, preventing power from getting to the
compressor 80 and the fan 20. The circuit breaker 120 will remain
open until the condensation pan drain(s) is/are cleared, the water
level returns to a normal state, and the circuit breaker is reset
manually. Any attempt to reset the circuit breaker while the pans
are still close to spilling will cause the circuit breaker to open
again. Such a circuit is shown in FIG. 4.
[0035] In the preferred embodiment, the liquid level sensor can be
an optoSchmitt sensor such as the LL series manufactured by
Honeywell. However, the sensor and its associated electronics can
be any type of liquid level sensor such as those described in
various engineering manuals. Many types of physical effects can be
used to determine liquid level: pressure, mechanical, conductive,
capacitive, photoelectric, heat-sensing, ultrasonic, nuclear,
microwave, and damped-oscillation effects have all been used as
liquid-level sensors. A good reference is "Handbook of
Transducers," by Harry N. Norton, Prentice-Hall, Englewood Cliffs,
N.J., 1989.
ADDITIONAL EMBODIMENT
[0036] An addition of an alarm 140 to the liquid level sensor
circuit can alert the homeowner or a neighbor to a potentially
damaging situation. Such a circuit is shown in FIG. 5.
ADDITIONAL EMBODIMENT
[0037] An addition of a liquid level sensor, associated
electronics, a circuit breaker and an alarm to "swamp" or
evaporative air conditioner drain pans can prevent overflow and
roof and home interior damage, since evaporative units are
generally roof-mounted.
OPERATION OF INVENTION
[0038] A home refrigeration air conditioning unit works by
compressing a refrigerant with a compressor 80 through cooling
coils 10 mounted in ductwork 30. A fan 20 circulates household air
across the cooling coils 10 through and out of the ductwork 30,
into the interior of the house, and back into the ductwork 30.
[0039] The cooling coils 10, fan 20 and ductwork 30 are usually
mounted in the attic of a house.
[0040] When the air is cooled by passing across the cooling coils
10, water condenses out of the air and falls into one or more
condensation pans 40, 50. This water is drained to the house sewer
plumbing, or to the outside of the house, via drains 45, 55 in the
pans.
[0041] Some installations of refrigeration units have only one
condensation pan, called the primary pan 40. Other installations
have two pans, called the primary pan 40 and the secondary pan 50.
The secondary pan 50 catches and drains any water spilling from the
primary pan 40 due to malfunction of the primary pan drain 45.
[0042] In some installations of the refrigeration units, the
primary pan 40 is an integral part of the fan-cooling coil-ductwork
assembly 10, 20, 30.
[0043] Some installations of the condensation pans have the drains
45, 55 on the pan sides, and some installations have the drains 45,
55 on the pan bottoms.
[0044] If both the primary pan drain 45 and secondary pan drain 55
are stopped up, or otherwise unable to conduct water away at a
sufficient rate from the pans, the pans will overflow into the
attic, causing structural and property damage to the house. In hot,
humid climates such as the Texas Gulf Coast, refrigeration units
can condense as much as 6 gallons of water a day from the air
during normal operation.
[0045] The present invention proposes adding a liquid level sensor
100 to each existing condensation pan 40, 50, to prevent water
overflow. The sensor 100 will determine when the liquid level in
the pans 40, 50 is about to overflow the edge of the pans, and will
shut off the electricity to the fan 20 and the compressor 80
through its power supply electronics and trigger circuit 110.
[0046] The electricity is shut off by a circuit breaker 120 in one
leg of the power lines to the compressor 80 and fan 20. This
circuit breaker is opened by the action of the trigger circuit 110
of the liquid level sensor. The compressor 80 and fan 20 cannot be
restarted before the circuit breaker 120 is manually re-engaged.
Since the liquid level sensor circuitry 110 is always attached to
the power lines, any attempt to reset the circuit breaker 120
before the pans 40, 50 are drained will result in the circuit
breaker 120 being opened again.
[0047] An addition of an alarm 130 to the liquid level sensor 100
and its electronics 110 will alert the homeowner, or neighbors or
friends if the occupants of the house are not at home.
ADVANTAGES
[0048] From the description above, three advantages of my invention
become apparent:
[0049] (a) the liquid level sensor and its circuitry shut off the
compressor and fan, thus eliminating condensed water overflow from
the condensation pans and subsequent damage to the home and its
contents.
[0050] (b) the compressor and fan cannot be started again until the
pan drain blockage(s) is/are cleared and the liquid level goes down
below the sensor level.
[0051] {circle over (c)} installation of such a protective system
to the drain pan of an evaporative air conditioner will also
prevent overflow and subsequent damage.
* * * * *