The American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) is a global organization for HVAC&R professionals. It promotes innovation in heating, cooling, ventilation, and refrigeration sciences. Headquartered in Atlanta, Georgia, ASHRAE provides resources like the four-volume Handbook (updated annually) and develops influential standards used in building codes and systems like LEED. Its mission focuses...

The reverse flow of exhaust gases or combustion by-products (like carbon monoxide) into an indoor space, rather than venting safely outside as intended. This issue can occur when there is negative air pressure inside a building, often caused by improperly balanced ventilation systems, blocked flues, or exhaust fans pulling air out of the space without...

Bioaerosols, or biological aerosols, are microscopic particles or droplets in the air that contain living organisms or were created by living organisms. These particles can include bacteria, viruses, fungal spores, pollen, or even fragments of organic material like skin cells or dust mite feces. Bioaerosols are naturally present in the air, but high concentrations, particularly...

A blower is a critical component in an HVAC system designed to move air throughout the system’s ductwork. It consists of a motor and fan assembly, which work together to push air across the heating or cooling elements and into your home's living spaces. During cooling, the blower circulates air across the evaporator coil, where...

A boiler is a closed vessel in which water or other fluids are heated to produce either hot water or steam. The heat used for this process can come from various sources, such as natural gas, oil, coal, electricity, or even renewable fuels. The resulting hot water or steam is then distributed through pipes for...

A method of joining two or more metals by melting a filler material (often called a brazing alloy), which flows into the joint by capillary action. The filler material has a melting point above 840°F (450°C) but below the melting point of the base metals being joined, which remain solid throughout the process. The process...

a standard unit of measurement used to quantify heat energy. Specifically, one BTU represents the amount of heat needed to increase (or decrease) the temperature of one pound of water by one degree Fahrenheit at standard pressure. The term is widely used in HVAC to measure the heating or cooling capacity of equipment. For instance,...

A measure of heat transfer over time, commonly used in the HVAC world to express the capacity of heating and cooling equipment. One BTU is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. When measured per hour (hence BTUh), this unit is used to describe...

BTU stands for British Thermal Unit, which is a standard unit of measurement used to quantify heat energy. Specifically, one BTU represents the amount of heat needed to increase (or decrease) the temperature of one pound of water by one degree Fahrenheit at standard pressure. The term is widely used in HVAC to measure the...

BTUh stands for "British Thermal Units per Hour," which is a measure of heat transfer over time, commonly used in the HVAC world to express the capacity of heating and cooling equipment. One BTU is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. When measured...