Tempered Fresh Air
Fresh air that has been heated/cooled prior to entering the indoor environment via fan coil units.

Dampers
Mechanical devices used to regulate the flow of air within an AHU system.

Inverter
An inverter varies the compressor speed of a heat pump to match the heating/ cooling requirement, acting as an energy efficient capacity controller.

Heat Pumps
A device which takes heat energy from a low temperature source and upgrades it to a higher temperature at which it can be usefully employed for heating and/or hot water.

Heat Recovery
Heat recovery is the collection and re-use of heat energy, arising in this case from ventilating a building, which would otherwise be lost in the stale extract air. Heat recovery can help to reduce the overall energy consumption by recovering this energy and thus reducing the heating/cooling load within the building.

Packaged
A packaged system is one that contains all the key components and controls for the system to operate fully.

Total Heat Recovery
Total heat recovery is the recovery of both sensible and latent heat. Sensible heat is transferrable heat that causes a rise or fall in air temperature. Latent heat is transferrable heat that causes a change in the humidity level or moisture content of the air.

MVHR
Mechanical Ventilation with Heat Recovery systems provide fresh air into a building to improve indoor air quality and climate control. The systems simultaneously supply and extract air and recover heat energy between the two air paths (heat recovery) whilst saving energy by reducing internal heating/cooling requirements.

DX (Direct Expansion) Coil
A direct expansion coil is one that uses a refrigerant such as R410A, to directly cool the air supplied to an occupied space, using the vapour compression cycle.

Free Cooling
When the outdoor air temperature is lower than the indoor air conditioned temperature and the system is in cooling mode, free cooling can occur whereby the system brings in the cooler fresh air from the outside directly inside to reduce the internal temperature therefore reducing the cooling load on the air conditioning system.