US5433377A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interlock and forced air furnace and HRV
Assignee: Carrier Corp
•
Filing: 1994-01-26
•
Granted: 1995-07-18
•
Expires: 2014-01-26
Abstract
Abstract An electrical interlock ties a heat recover ventilator to circulation air blower operation of an associated forced-air furnace or air conditioning system. This ensure that the blower circulates supply and return air within the building or dwelling. An interlock relay has its coil energized by the heat recovery ventilator, and a normally open contact tied to the control of a blower of the forced-air system. The furnace or air conditioner and the ventilator are operated by separate controls located within the building's comfort space. When the ventilator is operated, the circulation blower runs continuously, but thermostat actuate of the furnace or air conditioner above will not operate the ventilator.
Inventors
- 👤 James P. Sodo
- 👤 Steven O. Heard
- 👤 Robert W. Peitz, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:10
CPC Classifications
F; F24; F24D; F24D5/00; Y; Y02; Y02B; Y02B30/00; Y02B30/56
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
200 words
A forced air comfort system in which a circulation air blower is actuated in response to a thermostat control signal from a thermostat in an indoor comfort space and circulates indoor air from the comfort space through a supply duct to a heat exchanger which treats the indoor circulation air, and in which a supply duct returns the treated air from the heat exchanger to the comfort space; and comprising a heat recovery ventilator which discharges a portion of the circulation air to an outdoor environment and replaces the discharged circulation air with make-up air from the outdoor environment; the heat recovery ventilator including means to exchange heat between the discharged circulation air and the make-up air, blower means for inducing a flow of the make-up air from the outdoor environment and to induce a flow of the discharge air into the outdoor environment, and control means in the indoor comfort space electrically coupled to the blower means for electrically actuating same; and electrical interlock means coupling said furnace blower and the blower means of said heat recovery ventilator such that when the control means energize the blower means, the furnace blower is also energized to circulate said circulation air.
Claim 2
Dependent Claim
200 words
A forced air comfort system in which a circulation air blower is actuated in response to a thermostat control signal from a thermostat in an indoor comfort space and circulates indoor air from the comfort space through a supply duct to a heat exchanger which treats the indoor circulation air, and in which a supply duct returns the treated air from the heat exchanger to the comfort space; and comprising a heat recovery ventilator which discharges a portion of the circulation air to an outdoor environment and replaces the discharged circulation air with make-up air from the outdoor environment; the heat recovery ventilator including means to exchange heat between the discharged circulation air and the make-up air, blower means for inducing a flow of the make-up air from the outdoor environment and to induce a flow of the discharge air into the outdoor environment, and control means in the indoor comfort space electrically coupled to the blower means for electrically actuating same; and electrical interlock means coupling said furnace blower and the blower means of said heat recovery ventilator such that when the control means energize the blower means, the furnace blower is also energized to circulate said circulation air.
Claim 3
Dependent Claim
40 words
A forced air comfort system according to claim 1 wherein said interlock means includes a relay having an actuator coil electrically coupled to said blower means of said heat recovery ventilator, and contact means coupled to said circulation air blower.
Claim 4
Dependent Claim
41 words
A forced air comfort system according to claim 1 wherein said heat recovery ventilator has an indoor vent coupled to the return air duct and outdoor vents for discharging the discharge air outdoor and taking in the make-up air from outdoors.
Claim 5
Dependent Claim
67 words
A forced air comfort system according to claim 2 wherein said contact means includes a normally open contact coupled to said furnace blower, such that said furnace blower operates whenever said blower means of said heat recovery ventilator operates, but a call for actuation of the furnace blower without a call from said control means to actuate said heat recovery ventilator, will not operate said blower means.
Claim 6
Dependent Claim
53 words
A forced air comfort system according to claim 4, wherein said contact means further includes a normally closed contact disposed between said thermostat and a control for said furnace blower, such that actuation of said heat recovery ventilator opens said normally closed contact to isolate said thermostat from the control for said blower.
References Cited (Backward Citations)
US4044950A
Cited
US4175699A
Cited
US4293094A
Cited
US4408716A
Cited
US4477019A
Cited
US5183098A
Cited
US5046478A
Cited
US5224650A
Cited
US5257736A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-07-17 | 1999-01-16 | 1999-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-17 | 2003-01-16 | 2003-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-17 | 2007-01-16 | 2007-07-18 | $7700.00 | Window Closed / Lapsed |