COULD MVHR REPLACE ‘TRADITIONAL’ HEATING?
David Hilton looks at how mechanical ventilation with heat recovery could be used to provide heating and cooling in our homes
We are starting to get used to the fact that in an airtight home there is a need for ventilation. Under Part F of the Building Regulations, which documents the ventilation requirements to maintain indoor air quality, we basically have four systems to choose from — as outlined right.
ADDITIONAL HEATING AND COOLING
In many new homes an MVHR system (system 4 on the sidebar) is the method of choice. As homes become more efficient we can also add the option of additional heating and cooling to the ventilation system. The ducts need to be insulated in order to do so, but as they cover the whole house it could be an ideal alternative to traditional central heating systems.
Zehnder and Nuaire both have cooling options that can be added to their system designs, but there are also units available from Earth Save Products and Total Home Environment that can provide heating and cooling. These products have a small heat pump built into the MVHR unit that can be reversed to change the delivery option.
Total Home Environment are the suppliers of a HPV (heat pump ventilation) system that is ideal “in an airtight and well insulated home”. The company states: “The system adds heating or cooling through your ventilation ducts and may also be connected to the HPW300 which is a 300L cylinder with integrated heat pump to provide all your domestic hot water requirements. It has a secondary coil to provide up to 20m² of wet underfloor heating in bathrooms if required or accept heat from solar thermal panels. This heating and ventilating system can be over 1,200% efficient.”
The company also says the system can deliver between 1.2kw and 6kw of heating or 4.5kw of cooling, with up to 10.5kw of heating available with the addition of an electrical terminal heater.