A crankcase heater is an electric resistance heater installed on the compressor's crankcase in an HVAC system. Its purpose is to prevent liquid refrigerant from mixing with the compressor oil by keeping the refrigerant in a vapor state. This helps protect the compressor from damage caused by refrigerant-oil dilution, especially during colder weather or when...

CSA stands for Canadian Standards Association, which is an organization that develops and maintains standards to ensure quality, safety, and efficiency in various industries, including HVAC. In the HVAC field, CSA certification ensures that products, such as furnaces, air conditioners, and other components, meet specific safety and performance standards required for use in Canada. This...

Cubic Feet Per Minute (CFM) is a measurement of the volume of air moved by an HVAC system or component in one minute. It indicates how much air is circulated or pushed through the ducts, vents, or equipment, helping to gauge the system’s airflow performance. Proper CFM levels ensure efficient heating, cooling, and ventilation in...

A damper is a movable device, typically a metal plate or louver, installed inside ductwork in an HVAC system. Its primary function is to regulate and control airflow within the ducts. Dampers can be opened or closed, either manually or automatically, to balance airflow across different parts of the system. They are also a key...

Decibels (DB) are a unit used to measure the intensity or loudness of sound on a logarithmic scale. In HVAC systems, this measurement is often used to gauge the noise level generated by equipment such as air conditioners, furnaces, or fans. A lower decibel level indicates quieter operation, while a higher level implies louder noise....

Direct current (DC) is a type of electricity where the electric charge flows consistently in one direction, without changing polarity. In HVAC systems, DC is often used in components such as variable-speed motors and compressors, as it can provide more precise control and greater energy efficiency compared to alternating current (AC). DC technology in HVAC...

Decibel (dB) is a unit used to measure the intensity or loudness of sound on a logarithmic scale. It compares the power of a sound to a reference level, with a higher decibel value indicating a louder sound. For instance, a quiet library might measure around 40 dB, normal conversation typically falls between 50-60 dB,...

Defrost: The process of removing accumulated frost or ice from components in an HVAC system, such as the coils of an air conditioner or heat pump. Defrosting is essential to maintain proper airflow and system efficiency, as the buildup of frost can impede heat transfer. In modern systems, this process is often automated using a...

A degree-day is a measurement used in HVAC and energy analysis to estimate the demand for heating or cooling a building. It is calculated based on the difference between a base temperature—commonly 65 degrees Fahrenheit—and the average outdoor temperature for a day. For heating, degree-days are calculated when the outdoor temperature is below 65°F, and...

A device used to reduce the humidity level in the air by removing excess moisture. It works by drawing in humid air, cooling it on cold coils to condense the moisture into water droplets, and then reheating the now drier air before releasing it back into the room. This process prevents mold, mildew, and discomfort...