A type of heat exchanger used in HVAC systems, specifically as the evaporator coil in an air conditioning or heat pump system. It gets its name because the two slanted coil panels are positioned in a way that forms the shape of the letter “A.” These coils are typically found inside the indoor air handling...

Absolute humidity refers to the actual amount of water vapor present in a specific volume of air, measured in grams of water per cubic meter of air (g/m³). It is a physical measurement of how much water vapor is in the air without considering temperature or pressure. Absolute humidity is important in understanding the moisture...

In the context of HVAC systems, "AC" is short for "Air Conditioning." It refers to technologies and systems that are designed to control and alter the temperature, humidity, and overall air quality in a space for comfort or specific environmental conditions. In an air conditioning system, heat is removed from indoor air through a process...

The terms "AC" and "DC" refer to the type of electrical current that powers a device or system. "AC" stands for Alternating Current, which changes direction periodically and is commonly used for powering homes and HVAC systems. "DC" stands for Direct Current, which flows in a single direction and is typically used in battery-powered devices.

The Air Conditioning Contractors of America (ACCA) is a professional association that represents the interests of HVAC contractors across the United States. This organization develops industry standards, training programs, and resources to ensure quality, safety, and consistency in the design, installation, and maintenance of HVAC systems. ACCA is well-known for creating technical manuals such as...

An accumulator is a component commonly found in HVAC systems, especially in systems using heat pumps and air conditioners. It is a storage tank located between the evaporator and the compressor. Its primary purpose is to protect the compressor from liquid refrigerant. Instead of storing "excess refrigerant vapor" as mentioned in the provided definition, the...

In the context of HVAC, the term "acoustical" pertains to the study, control, or management of sound within a space, often focusing on noise reduction or sound quality. It relates to how HVAC systems impact the levels and characteristics of sound within an indoor environment. For example, acoustical performance considers how duct design, insulation, fan...

Annual Fuel Utilization Efficiency (AFUE) is a standardized measure of how efficiently a gas furnace or boiler converts fuel into usable heat over an entire heating season. The efficiency is expressed as a percentage, representing the amount of fuel energy that is actually converted into heat versus the portion that is lost during combustion or...

AGA stands for the American Gas Association, which is a trade organization representing companies that deliver natural gas to homes and businesses across the United States. The AGA plays an important role in developing industry safety standards, regulations, and certifications, particularly for natural gas appliances and systems, many of which are used in HVAC applications...

The term "AHRI" stands for the Air-Conditioning, Heating, and Refrigeration Institute. It is a trade association that represents manufacturers of HVAC (heating, ventilation, and air conditioning), water heating, and refrigeration equipment. AHRI develops technical standards and guidelines, certifies product performance, and advocates for the industry to ensure high-quality and energy-efficient equipment in the marketplace. Their...