Glossary of Terms

British Thermal Unit (BTU) - is a measure of the thermal capacity of a fluid

Condenser Section – the side of the system which transfers heat out of the system into the outside air by condensing refrigerant

Condenser Coil – coil that exchanges heat from the refrigeration system into the outside air

Condenser Fan – fan that moves outside air through the condenser coil to remove heat and blows it back outside

Compressor – a pump which circulates refrigerant within the system where it absorbs heat by changing from a liquid into a gas where it is compressed and then cooled back to a liquid

CFM – (Cubic feet per minute) - A unit of measurement for the amount of air handled by the fan

Electronic Control Panel – also called a user interface – displays the temperature and humidity in the room and where the user can control the operation of the unit including setting fan speeds, occupied and unoccupied modes, and temperature set-points

Electrical Panel – an internal panel that contains all the electrical devices and wiring

Evaporator Section – the side of the system that cools the room air by absorbing heat into the liquid refrigerant changing it into a gas

Evaporator Fan – also called the Room Air Fan – fan which recirculates room air through the evaporator (cooling) coil, the heating coil and the HEPA filter to maintain temperature and cleanliness in the room

Evaporator Cooling Coil – coil that cools and dehumidifies the room air by absorbing heat from the air Exhaust Air - refers to the room air leaving the heat exchanger and being exhausted to the outside

Exhaust Air Fan – fan which draws room air out of the return air section in the unit through the heat exchanger and exhausts it to the outside

Grill – louvered inlet or outlet plates that direct the airflow or protect the inside of the unit

Heat Exchanger – an air-to-air aluminum plate heat exchanger that transfers heat between the exhaust air and the outside air to save energy

Heating Coil – an electrical resistance heating coil located in the evaporator section where it heats the room air to maintain room temperature

High Efficiency Particulate Air (HEPA) filter – a specially constructed, high-efficiency filter with a minimum efficiency of 95% DOP tested on 0.3 micron particles

LCDI Plug – leakage current detection interrupter plug – reduces risk of an arc fault occurring in the power cord

Occupied/Unoccupied Switch – changes operating mode of unit from continuous operation to thermostatically controlled intermittent operation (refer to “Controls” section of the Installation, Operation & Maintenance Manual)

Outside Air – refers to the outside air entering the heat exchanger and then into the room

Outside Air Fan – draws outside air through a pre-filter and blows it through the heat exchanger into the return air before it enters the evaporator section where it will be conditioned

Pre-filter – washable filters used in the outside air inlet and in the room return air to capture large particles before they enter the unit

Return Air – refers to the room air returning or entering into the unit

Supply Air – refers to the room air leaving the unit after it has been conditioned

Setpoint - the desired room temperature set on the thermostat

Volatile Organic Compounds (VOCs) – organic chemicals containing carbon, oxygen, hydrogen, chlorine, and other atoms. Volatile chemicals produce vapors readily. Volatile organic chemicals include formaldehyde, gasoline, industrial chemicals such as benzene, solvents such as toluene and xylene, and tetrachloroethylene (perchloroethylene, the principal dry cleaning solvent). Many volatile organic chemicals are also hazardous air pollutants.

Underwriters Laboratories (UL) – a private research firm located in the United States that attempts to classify and determine the safety of various materials and products