SYSTEM AND METHOD OF FREEZE PROTECTION OF A HEAT EXCHANGER IN AN HVAC SYSTEM

摘要

A system and method of heat exchanger freeze protection for an HVAC system by operating an indoor unit assembly and an outdoor unit assembly in a cooling mode and operating a fan at an initial airflow, operating a temperature sensor to measure a temperature value of a heat exchanger, at the expiration of a first predetermined time period, determining whether the temperature value is less than or equal to a first temperature preset value, determining whether a current airflow multiplier is equal to a maximum airflow multiplier limit, increasing the current airflow by an airflow offset multiplier if the current airflow multiplier is less than or equal to the maximum airflow multiplier limit and the temperature value is less than or equal to the first temperature preset, and operating the fan at an increased airflow to move more air across the heat exchanger.

主权项

1. A method of heat exchanger freeze protection for an HVAC system, the HVAC system including an indoor unit assembly further including a heat exchanger including a suction port and a liquid port, a fan, and a temperature sensor operably coupled to the heat exchanger; an outdoor unit assembly operably coupled to the indoor unit assembly, and a controller operably coupled to the indoor unit assembly and the outdoor unit assembly, the method comprising the steps of:
(a) operating the indoor unit assembly and the outdoor unit assembly in a cooling mode, and operating the fan at an initial airflow; (b) operating the temperature sensor to measure a temperature value of the heat exchanger, upon expiration of a predetermined time period; (c) determining whether the temperature value is less than or equal to a first temperature preset value; (d) operating the controller to increase a current airflow multiplier by an airflow offset if the current airflow multiplier is less than a maximum airflow multiplier limit and the temperature value is less than or equal to the first temperature preset value; (e) operating the fan at an increased airflow determined by the formula:
Current airflow=Initial airflow×(Current airflow multiplier+airflow offset).