19-02-2013, 09:38 AM
Heat recovery in an HVAC group
Introduction
The hospital in this case is a medium-sized institution. In the hospital there are
various HVAC systems; most of them have heat recovery but some do not.
Present situation
At present there is no heat recovery from the extraction air in the office HVAC
systems, which means that energy is lost unnecessarily. In the air ducts leading
to and from the HVAC unit there is sufficient space to install heat recovery.
Proposal
A Twin-Coil heat recovery system could recover around 50% of the heat from the
extraction air. The Twin-Coil system was chosen because of the practical
feasibility of installing it in the existing air ducts.
Estimated savings & investment
The savings are achieved in terms of gas consumption, because less air needs
to be heated due to the fact that some of the pulsed air is heated using heat from
the extraction air. On the other hand the amount of electrical power consumed is
higher, since fitting a Twin-Coil creates additional resistance in the air duct which
has to be overcome by the fans.