Detecting and correcting enthalpy wheel failure modes

Patent metadata

Field	Value
Publication number	US-10197344-B2
Application number	US-201615192608-A
Country	US
Kind code	B2
Filing date	Jun 24, 2016
Priority date	Oct 6, 2011
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

A heating ventilation and cooling system includes an energy recovery ventilator (ERV). The ERV is configured to produce an inlet airstream and an exhaust airstream. An enthalpy wheel within the energy recovery ventilator is operable to transport heat between the inlet and exhaust airstreams. A pressure transducer is configured to determine a backpressure across the enthalpy wheel. A controller is configured to determine, in response to the backpressure, an operational characteristic of the enthalpy wheel.

First claim

What is claimed is:

1. A method for heating, ventilating, and cooling comprising:
determining an outside air temperature;
recording a rate of change of pressure in a region of an energy recovery ventilator, wherein the energy recovery ventilator is operable to produce an inlet airstream and an exhaust airstream;
determining that an enthalpy wheel positioned within the energy recovery ventilator and operable to transport heat between the inlet and exhaust airstreams is in a frosted condition if the rate of change of air pressure within the energy recovery ventilator is greater than a stored normal rate of change of air pressure and the outside air temperature is below a stored temperature value;
determining that the enthalpy wheel is in a disabled condition if the rate of change of the air pressure within the energy recovery ventilator is greater than the stored normal rate of change of air pressure and the outside air temperature is higher than the stored temperature value; and
setting the operating speed of an exhaust blower to a predetermined speed based on the determined condition of the enthalpy wheel.

2. The method as recited in claim 1 , wherein the energy recovery ventilator is operable to produce the inlet airstream by drawing outside air into the energy recovery ventilator.

3. The method as recited in claim 1 , further comprising:
measuring air pressure within at least a region of the energy recovery ventilator;
determining a pressure differential across the enthalpy wheel based, at least in part, upon the measured air pressure; and
determining an airflow rate through the enthalpy wheel based, at least in part, upon the pressure differential.

4. The method as recited in claim 1 , wherein the enthalpy wheel is one of two enthalpy wheels within the energy recovery ventilator, and the method further comprises determining that one of the enthalpy wheels is disabled.

5. The method as recited in claim 1 , further comprising directing the inlet airstream into a conditioning unit coupled to the energy recovery ventilator.

6. The method as recited in claim 4 , further comprising reducing airflow of the inlet and exhaust airstreams in the event that one of the enthalpy wheels is inoperable.

7. The method as recited in claim 4 , further comprising communicating an alarm condition in the event that one of the enthalpy wheels is inoperable.

Assignees

• Lennox Ind Inc

Inventors

• Mckie Justin
• Perez Eric
• Thomas Greg
• Schneider Steve

Classifications

• F24F2203/104

  Heat exchanger wheel · CPC title

• F28D19/041

  with axial flow through the intermediate heat-transfer medium · CPC title

• F24F11/32

  Responding to malfunctions or emergencies · CPC title

• F24F11/62

  characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values · CPC title

• Y10T29/4935

  Heat exchanger or boiler making · CPC title