Definition

Air-to-air Plate or Tube Heat Exchanger: Heat Exchanger designed to transfer thermal energy (sensible or total) from one air stream to another without moving parts. Heat transfer surfaces are in form of plates or tubes. This Heat Exchanger may have parallel flow, cross flow or counter flow construction or a combination of these.

Regenerative Heat Exchanger: Device incorporating an alternating storage system or a rotating cylinder or wheel for the purpose of transferring energy (sensible or total) from one air stream to the other. It incorporates heat transfer material, a drive mechanism, a casing or frame, and includes any seals which are provided to retard the bypassing and leakage of air from one air stream to the other.

Run Around Coil: Matched pair of coil heat exchangers, piped together in a continuous loop through which the heat-exchange medium (water or a water/anti-freeze mix) flows. A pump pack ensures that the medium keeps flowing in a single direction at a constant rate.

Heat Pipes: Battery of multi-row finned heat pipe tubes located within both the supply and exhaust air streams. Within the exhaust air side of the heat pipe, the refrigerant evaporates, taking its heat from the extract air. The refrigerant vapour moves towards the cooler end of the tube, within the supply air side of the device, where it condenses and gives up its heat. The condensed refrigerant returns by a combination of gravity and capillary action in the wick.

Collection details

Collection resumed in 2022

Previously suspended, this data collection is currently resumed in 2022 and will be organised annually.

Initially, it started in 2015 and it concerned 19 manufacturers. The data were available in units with a first split by regenerative heat exchangers (condensation rotors, hydroscopic rotors and scorption rotors), a second split by plate heat exchangers (cross flow and counter flow) and a third split by run-around-coils and heat pipes.