US6993414B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Detection of clogged filter in an HVAC system
Assignee: Carrier Corp
•
Filing: 2003-12-18
•
Granted: 2006-01-31
•
Expires: 2023-12-18
Abstract
Abstract Static pressures are measured in an HVAC system and utilized to predict the condition of a filter in the HVAC system. As the filter becomes clogged, the static pressure can be expected to increase. Changes in the static pressure are determined periodically, and utilized to predict the condition of the filter. A display provides a user with an indication of the current condition of the filter, and a recommendation to replace the filter once it reaches a predetermined condition.
Inventors
- 👤 Rajendra K. Shah
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:41
CPC Classifications
G; G05; G05D; G05D23/00; B; B01; B01D; B01D46/00; B01D46/0084; B01D46/0086; B01D46/42; B01D46/44; B01D46/446; F; F24; F24F; F24F11/00; F24F11/30; F24F11/50; F24F11/52; G05B; G05B21/00; B01D2279/00; B01D2279/50; F24F11/32; F24F11/39
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
125 words
An HVAC system comprising: a fan, and a supply duct for supplying air to said fan, said fan being operable to deliver air from said supply duct to an environment to be conditioned, and a filter mounted to remove impurities from said air being delivered by said fan to said environment; a control being operable to receive an indication of pressures within said system, and determine the condition of said filter based upon said pressures; said pressures received by said control includes both a previous pressure and a current pressure, and the difference between said current and previous pressures being utilized to provide an indication of the condition of a filter; and a display provides an indication of a percentage clogged condition of the filter.
Claim 2
Dependent Claim
125 words
An HVAC system comprising: a fan, and a supply duct for supplying air to said fan, said fan being operable to deliver air from said supply duct to an environment to be conditioned, and a filter mounted to remove impurities from said air being delivered by said fan to said environment; a control being operable to receive an indication of pressures within said system, and determine the condition of said filter based upon said pressures; said pressures received by said control includes both a previous pressure and a current pressure, and the difference between said current and previous pressures being utilized to provide an indication of the condition of a filter; and a display provides an indication of a percentage clogged condition of the filter.
Claim 3
Dependent Claim
39 words
The HVAC system as set forth in claim 1 , wherein a maximum pressure is defined, and if said current pressure exceeds said maximum pressure, then an indication is made that the filter is immediately in need of replacement.
Claim 4
Dependent Claim
33 words
The HVAC system as set forth in claim 1 , wherein said display includes an indication of a suggestion to replace the filter once said condition of said filter reaches a predetermined condition.
Claim 5
Dependent Claim
18 words
The HVAC system as set forth in claim 1 , wherein said previous pressure is an initial pressure.
Claim 6
Dependent Claim
30 words
The HVAC system as set forth in claim 4 , wherein said control receives a replacement for said previous pressure when a reset button associated with said control is actuated.
Claim 7
Dependent Claim
20 words
The HVAC system as set forth in claim 1 , wherein said current and previous pressure are static pressure readings.
Claim 8
Dependent Claim
160 words
An HVAC system comprising: a fan and a supply duct for supplying air to said fan being operable to deliver air from said supply duct to an environment to be conditioned, and a filter mounted to remove impurities from said air being delivered by said fan to said environment; a control being operable to receive an indication of pressures within said system, and determine the condition of said filter based upon said pressures; and said pressures received by said control includes both a previous pressure and a current pressure, and the difference between said current and previous pressures being utilized to provide an indication of the condition of a filter; said current and previous pressure are static pressure readings; and said current and previous static pressure readings are utilized with the following formula to determine filter condition: FILTER USED %=(CURRENT-PREVIOUS)/( X *(MAXIMUM-PREVIOUS)), wherein x is a multiplier, and MAXIMUM is a previously defined maximum pressure indicative of a clogged filter.
Claim 9
Dependent Claim
160 words
An HVAC system comprising: a fan and a supply duct for supplying air to said fan being operable to deliver air from said supply duct to an environment to be conditioned, and a filter mounted to remove impurities from said air being delivered by said fan to said environment; a control being operable to receive an indication of pressures within said system, and determine the condition of said filter based upon said pressures; and said pressures received by said control includes both a previous pressure and a current pressure, and the difference between said current and previous pressures being utilized to provide an indication of the condition of a filter; said current and previous pressure are static pressure readings; and said current and previous static pressure readings are utilized with the following formula to determine filter condition: FILTER USED %=(CURRENT-PREVIOUS)/( X *(MAXIMUM-PREVIOUS)), wherein x is a multiplier, and MAXIMUM is a previously defined maximum pressure indicative of a clogged filter.
Claim 10
Dependent Claim
24 words
The HVAC system as set forth in claim 7 , wherein a display provides an indication of a percentage clogged condition of the filter.
Claim 11
Dependent Claim
20 words
The HVAC system as set forth in claim 7 , wherein X is a multiplier that is less than 1.0.
Claim 12
Dependent Claim
16 words
The HVAC system as set forth in claim 9 , wherein X is equal to 0.6.
Claim 13
Dependent Claim
20 words
The HVAC system as set forth in claim 7 , wherein said previous pressure reading is an initial pressure reading.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2009-01-30 | 2009-08-01 | 2010-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2013-01-30 | 2013-08-01 | 2014-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2017-01-30 | 2017-08-01 | 2018-01-31 | $7700.00 | Window Closed / Lapsed |