Systems and methods for detecting air filter fouling in a climate control system

Patent metadata

Field	Value
Publication number	US-11543147-B1
Application number	US-201916666037-A
Country	US
Kind code	B1
Filing date	Oct 28, 2019
Priority date	Oct 28, 2019
Publication date	Jan 3, 2023
Grant date	Jan 3, 2023

Abstract

Methods and related systems for operating a climate control system for an indoor space are disclosed. In an embodiment, the method includes increasing a speed of a fan of the climate control system, and determining a first fitted external static pressure (ESP) function from a first plurality of airflow values and a first plurality of ESP values. Additionally, the method includes obtaining a baseline ESP from the first fitted ESP function, and determining a second fitted ESP function from a second plurality of airflow values and a second plurality of ESP values collected at least one week after the first plurality of airflow values and the first plurality of ESP values are collected. Further, the method includes comparing the first calculated ESP obtained from the second fitted ESP function to the baseline ESP to determine a condition of an air filter of the climate control system.

First claim

What is claimed is:

1. A method of operating a climate control system for an indoor space, the method comprising:
(A) conducting a first active filter test on the climate control system at a first time, the climate control system being installed at a given location and including a given air filter during the first active filter test, the first active filter test including:
(a) increasing, from idle, a speed of an indoor fan of the climate control system to increase an airflow through the indoor space,
(b) determining a first fitted external static pressure (ESP) function from a first plurality of airflow values and a first plurality of ESP values, and
(c) obtaining a baseline ESP value of the climate control system from the first fitted ESP function; and

(B) conducting a second active filter test on the climate control system at a second time, the climate control system being installed at the given location and including the given air filter during the second active filter test, the second time being at least one week after the first time, the second active filter test including:
(d) determining a second fitted ESP function from a second plurality of airflow values and a second plurality of ESP values,
(e) obtaining a first calculated ESP value of the climate control system from the second fitted ESP function, and
(f) comparing the first calculated ESP value to the baseline ESP value to determine a condition of an air filter of the climate control system.

2. The method of claim 1 , wherein (d) comprises:
(d1) determining an airflow start value and an ESP start value at a first airflow rate; and
(d2) determining an airflow end value and an ESP end value at a second airflow rate which is greater than the first airflow rate.

3. The method of claim 2 , wherein (d1) comprises identifying a first non-zero airflow of the first plurality of airflow values.

4. The method of claim 2 , wherein (d2) comprises identifying when a pseudo-steady state maximum airflow and a pseudo-steady state maximum ESP have been achieved.

5. The method of claim 1 , wherein (f) comprises:
(f1) determining a percentage increase in the first calculated ESP value over the baseline ESP value; and
(f2) comparing the determined percentage increase with a predetermined maximum percentage increase.

6. The method of claim 1 , further comprising:
(g) issuing an alert to a user of the climate control system to service the air filter in response to the determined percentage increase being greater than the predetermined maximum percentage increase.

7. The method of claim 1 , wherein the first and the second active filter test include operating the climate control system in a fan only mode.

8. The method of claim 1 , further comprising:
(g) measuring a speed and a torque of a motor of the indoor fan, wherein the first plurality of airflow values, the second plurality of airflow values, the first plurality of ESP values, and the second plurality of ESP values are estimated from the measured speed and the measured torque of the motor of the indoor fan.

9. The method of claim 1 , further comprising:
(C) conducting a third active filter test on the climate control system at a third time, the climate control system being installed at the given location and including the given air filter during the third active filter test, the third time being at least one week after the second time, the third active filter test including:
(g) determining a third fitted ESP function from a third plurality of airflow values and a third plurality of ESP values,
(h) obtaining a second calculated ESP value of the climate control system from the third fitted ESP function, and
(i) comparing the second calculated ESP value to the baseline ESP value to determine the condition of the air filter of the climate control system.

10. A climate control system for an indoor space, the climate control system comprising:
an indoor fan configured to produce an airflow through the indoor space;
an air filter configured to filter contaminants in the airflow produced by the indoor fan;
a controller to be coupled to the indoor fan, wherein the controller is configured to:
conduct a first active filter test on the climate control system at a first time, the climate control system being installed at a given location and including the air filter during the first active filter test, the first active filter test including:
increasing, from idle, a speed of the indoor fan of the climate control system to increase the airflow through the indoor space,
determining a first fitted external static pressure (ESP) function from a first plurality of airflow values and a first plurality of ESP values, and
obtaining a baseline ESP value of the climate control system from the first fitted ESP function;

conduct a second active filter test on the climate control system at a second time, the climate control system being installed at the given location and including the air filter during the second active filter test, the second time being at least one week after the first time, the second active filter test including:
determining a second fitted ESP function from a second plurality of airflow values and a second plurality of ESP values collected by the controller at least one week after the first plurality of airflow values and the first plurality of ESP values are collected by the controller;
obtaining a first calculated ESP value of the climate control system from the second fitted ESP function; and
comparing the first calculated ESP value to the baseline ESP value to determine a condition of the air filter of the climate control system.

11. The climate control system of claim 10 , wherein the controller is configured to enter a selected airflow into the second fitted ESP function, and wherein the selected airflow is normalized by a maximum airflow of the indoor fan in the second fitted ESP function.

12. The climate control system of claim 10 , wherein:
at least one of the first plurality of airflow values and the second plurality of airflow values are bounded by an airflow start value at a first airflow rate determined by the controller and an airflow end value at a second airflow rate determined by the controller which is greater than the first airflow rate; and
at least one of the first plurality of ESP values and the second plurality of ESP values are bounded by an ESP start value at the first airflow rate and an ESP end value at the second airflow rate.

13. The climate control system of claim 12 , wherein the controller is configured to determine a percentage increase in the first calculated ESP value over the baseline ESP value and compare the determined percentage increase with a predetermined maximum percentage increase.

14. The climate control system of claim 13 , wherein the controller is configured to issue an alert to a user of the climate control system to service the air filter in response to the determined percentage increase being greater than the predetermined maximum percentage increase.

15. The climate control system of claim 10 , wherein the controller is configured to:
measure a speed and a torque of a motor of the indoor fan; and
estimate the first plurality of airflow values, the second plurality of airflow values, the first plurality of ESP values, and the second plurality of ESP values from the measured speed and the measured torque of the motor of the indoor fan.

16. The climate control system of claim 10 , wherein the controller is configured to:
conduct a third active filter test on the climate control system at a third time,

Assignees

• Trane Int Inc

Inventors

• Rite Raymond Walter

Classifications

• B01D46/446

  by pressure measuring · CPC title

• B01D46/0086

  Filter condition indicators · CPC title

• F24F11/39 Primary

  Monitoring filter performance · CPC title

• F24F11/745 Primary

  the air flow rate increasing with an increase of air-current or wind pressure · CPC title

• B01D46/444

  by flow measuring · CPC title