Patent US4086781A successfully refreshed from Google Patents.
US4086781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable air volume air conditioning system
Assignee: International Telephone and Telegraph Corp
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Filing: 1976-04-23
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Granted: 1978-05-02
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Expires: 1996-04-23
Abstract
Abstract A variable air volume air conditioning system is provided with thermostat controlled variable air volume terminal boxes for controlling the volume of constant temperature conditioned air provided to each space to be conditioned. The conditioned air is delivered through a short pressure recovery duct to a trunk duct by a centrifugal fan having forward curved blades. The trunk duct pressure is maintained substantially constant by control vanes disposed at the recovery duct outlet, said control vanes being responsive to an increase in duct pressure to close the duct outlet and unload the fan, thereby reducing the energy consumed by the fan. Economizer operation is provided by the use of return air dampers and outside air dampers controlled in response to outside air temperature and air supply duct temperature to mix outside air and return air to reduce the amount of mechanical refrigeration required. A power air return means is provided for returning air to the system from the spaces that are conditioned and for controlling the amount of return air in accordance with the volume of air delivered to the conditioned spaces.
Inventors
- 👤 Herbert M. Brody
- 👤 George L. Weigle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:47
CPC Classifications
F; F24; F24F; F24F11/00; F24F11/70; F24F11/72; F24F11/74; F24F3/00; F24F3/044; F24F3/0442
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
154 words
A variable air volume air conditioning system, comprising: means for providing air at a predetermined temperature; a forward curved fan for delivering said air, said fan having an inlet for receiving the air from the last mentioned means and an outlet; a pressure recovery duct having one end connected to the outlet of said fan; outlet control vane means disposed at a second end of said pressure recovery duct for controlling the volume of air flow from said fan in response to air pressure downstream from the outlet control vane means; duct means for directing the air from the outlet control vane means to a space to be conditioned; and air volume control means for controlling the volume of air supplied to a space to be conditioned in accordance with the cooling requirements of said space, whereby the air pressure in the duct means is maintained substantially constant by the outlet control vane means.
Claim 2
Dependent Claim
154 words
A variable air volume air conditioning system, comprising: means for providing air at a predetermined temperature; a forward curved fan for delivering said air, said fan having an inlet for receiving the air from the last mentioned means and an outlet; a pressure recovery duct having one end connected to the outlet of said fan; outlet control vane means disposed at a second end of said pressure recovery duct for controlling the volume of air flow from said fan in response to air pressure downstream from the outlet control vane means; duct means for directing the air from the outlet control vane means to a space to be conditioned; and air volume control means for controlling the volume of air supplied to a space to be conditioned in accordance with the cooling requirements of said space, whereby the air pressure in the duct means is maintained substantially constant by the outlet control vane means.
Claim 3
Dependent Claim
15 words
A system as described in claim 1, additionally comprising refrigeration means for cooling said air.
Claim 4
Dependent Claim
20 words
A system as described in claim 2, additionally comprising means for controlling the air temperature to a predetermined set point.
Claim 5
Dependent Claim
22 words
A system as described in claim 1, having a plurality of forward curved fans having outlets connected to the pressure recovery duct.
Claim 6
Dependent Claim
17 words
A system as described in claim 4, wherein said fans are connected to a common drive shaft.
Claim 7
Dependent Claim
31 words
A system as described in claim 1, wherein the outlet control vane means comprises a plurality of oppositely disposed outlet vanes for controlling the volume of air delivered by the fan.
Claim 8
Dependent Claim
116 words
A system as described in claim 3, wherein the outlet control vane means includes an output for providing a signal corresponding to the position of the outlet control vane means and the means for controlling the air temperature comprises a dual set point temperature controller, the system additionally comprising means connecting the output of the outlet control vane means to the means for controlling air temperature, said means for controlling air temperature being responsive to the signal received from the outlet control vane means for changing the temperature set point, whereby the temperature set point of the means for controlling the air temperature is changed in response to the volume of air flow from the fan.
Claim 9
Dependent Claim
96 words
A variable air volume air conditioning system, comprising: means for providing air at a predetermined temperature; a forward curved fan having an inlet for receiving said air and an outlet for delivering said air; a pressure recovery duct having an inlet connected to the outlet of said fan; outlet control vane means connected to an outlet of the pressure recovery duct for controlling the volume of air delivered by said fan in response to the cooling requirements of a space to be conditioned; and duct means for directing the air to the space to be conditioned.
Claim 10
Dependent Claim
96 words
A variable air volume air conditioning system, comprising: means for providing air at a predetermined temperature; a forward curved fan having an inlet for receiving said air and an outlet for delivering said air; a pressure recovery duct having an inlet connected to the outlet of said fan; outlet control vane means connected to an outlet of the pressure recovery duct for controlling the volume of air delivered by said fan in response to the cooling requirements of a space to be conditioned; and duct means for directing the air to the space to be conditioned.
Claim 11
Dependent Claim
95 words
A variable air volume air conditioning system as described in claim 8, additionally comprising: means associated with the outlet control vane means for providing a signal corresponding to the position of the outlet control means; and means for controlling the first mentioned means in response to the signal from the outlet control vane means to maintain a first predetermined air temperature when a first volume of air or more is delivered to said space and to maintain a second predetermined air temperature when less than the first volume of air is delivered to said space.
References Cited (Backward Citations)
US2813235A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-01 | 1981-10-31 | 1982-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-01 | 1985-10-31 | 1986-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-01 | 1989-10-31 | 1990-05-02 | $7700.00 | Window Closed / Lapsed |