Heat loss calculation check

[JohnMo]

On 21/12/2024 at 00:31, Gordo said:

As air is blown in it is sucked out at a measured / adjusted rate to be left "slightly" pressurise in the house

Sorry this is incorrect. The MVHR in and out flows, are balanced - same is taken out as brought in, so house is neither pressurised or depressurised by MVHR. 

 

MVHR also slowly decreases house temp (assuming colder outside) as the efficiency of the heat exchanger within the MVHR unit will never be 100%. Ventilation heat loss will be based on approximately 10 to 20% of the overall flow rate of the MVHR unit, plus natural ventilation heat losses based on house airtightness. So airtight house, ventilation losses are almost all losses produced by MVHR, leaky house plus MVHR, are MVHR losses plus natural air leakage losses.