HVAC and BEMS

A form of thermal energy resulting from combustion, chemical reaction, friction, or movement of electricity.  As a thermodynamic condition, heat, at a constant pressure, is equal to internal or intrinsic energy plus pressure times volume.

The heat that flows from the building interior, through the building envelope to the outside environment.

The ratio of fuel energy input as heat per unit of network output; a measure of a power plant thermal efficiency, generally expressed as Btu per net kilowatt hour.

The grilled opening into a room by which the amount of warm air from a furnace can be directed or controlled; may include a damper.

The quantity of heat necessary to raise the temperature of a specific mass of a substance by one degree.

The number of degrees per day that the daily average temperature (the mean of the maximum and minimum recorded temperatures) is below a base temperature, usually 18.333°C / 65°F, unless otherwise specified; used to determine indoor space heating requirements and heating system sizing.  Total HDD is the cumulative total for the year/heating season.  The higher the HDD for a location, the colder the daily average temperature(s).

The rate of heat flow required to maintain a specific indoor temperature; usually measured in Btu per hour.

HVAC (pronounced either "H-V-A-C" or "H-vak") is an initialism or acronym that stands for "heating, ventilation, and air conditioning".  HVAC is sometimes referred to as climate control and is particularly important in the design of medium to large industrial sites and office building such as skyscrapers, and in marine environments such as aquariums, where humidity and temperature must all be closely regulated whilst maintaining safe and healthy conditions within.

An efficiency standard of air filters.

A nationally recognised energy rating program that gives builders, mortgage lenders, secondary lending markets, homeowners, sellers, and buyers a precise evaluation of energy losing deficiencies in homes.  Builders can use the system to gauge the energy quality in their home and also to have a star rating on their home to compare to other similarly built homes.