Technical Notice from Beijing McQuay Air Conditioning Repair Center, Beijing McQuay Air Conditioning After-sales Service Hotline.
In central air conditioning systems, pre-heaters, secondary heaters, and coil coolers are all surface heat exchangers. This means the working fluid flows inside the tubes while air flows outside them. The measurement and adjustment methods for surface heat exchangers include:
(1) Measurement of the heat exchanger area.
(2) Measurement of heat exchanger resistance.
(3) Measurement of airflow at different wind pressures. Draw curves for wind pressure vs. airflow and resistance vs. airflow.
(4) Measurement of the temperature difference between the air and the working fluid at their inlets and outlets, which allows calculation of the heat exchange amount, heat transfer coefficient, and heat transfer efficiency.
(5) Determination of the flow resistance of the working fluid inside the tube.
(6) Comprehensive project evaluation: If the working fluid flow is insufficient, the inlet and outlet pipe diameters should be increased; if the facing wind area is inadequate, a comprehensive consideration, adjustment, and improvement of the surface heat exchanger should be made.
How does McQuay Air Conditioning measure and debug coil coolers and heaters?