I was interested to note from Gavin Hodgson’s article (BSj 05/06) that BRE is now promoting mechanical ventilation with heat recovery (MVHR) systems - but he is wrong to think that using the MVHR as the main heating system is something new. The Danish Genvex system has been offering this facility in the UK (and throughout Europe) for well-insulated houses for about 20 years.

If you incorporate a heat pump into the unit (with the motor in the supply airstream), as Genvex does, a coefficient of performance of well over five is easily obtainable and was independently measured in the 1980s. The top-up can now be provided with fast-response, in-duct ceramic elements.

Can Gavin tell me if such a Heat Pump MVHR system will ever be acknowledged in the SAP calculation procedure?

Dr Neil Sturrock FCIBSE

Source

Building Sustainable Design