Air changes – the number of times the air is changed completely in a room
Dry air – in air balance terms, air without water vapor in it.
Outside air (OSA) – air that is outside of the building or space.
Return air- air being returned from the conditioned space.
Supply air- air that is moving to a space
BTU – the heat required to raise the temperature of a lb of water 1 degree F.
Ceiling outlet – an air diffuser located in a ceiling
Coil – a cooling or heating element that is made of pipe or tubing.
Condensation – the process of changing a vapor into liquid by the extraction of heat.
Critical velocity – the velocity above which air flow becomes turbulent.
Chimney effect – air or gas in a duct or other vertical passage rising when it is heated.
Damper – a valve or plate used to regulate the flow of air.
Duct – a pathway made of many different types of material that will move air from one location to another.
Evaporation – change of state from liquid to vapor.
HVAC – an acronym for Heating Ventilation & Air Conditioning