When you first start checking your supply air with a thermo-hygrometer, you may notice that the relative humidity is REALLY HIGH. Often, the RH in a supply duct will be between 85% and 96% relative humidity on a system that is functioning as designed. The reason for this is fairly simple: In order for dehumidification […]

Many HVAC/R technicians (including me) describe the compressor as the heart of the refrigeration cycle. It prepares the refrigerant for the condensing process, which is crucial for heat rejection.  However, some refrigeration methods don’t require a compressor. In this article, we’ll look at those methods and their applications.   Gas movement without compressors As you […]

Does setting a thermostat too low cause an air conditioning system set in cool mode to freeze? The answer is no, at least not directly. However, low evaporator load (low return temperature or low airflow) and low outdoor ambient temperature can lead to evaporator coil freezing. Low indoor setpoint can lead to low return air […]