How do you determine the correct sizing of an HRV?
...Home Ventilating Institute a home should provide 0.35 ACH which is approximately 50CFM per 1000 sq ft (this recommendation is based on ASHRAE 62.2) but it doesnt say if this is additional ventilation to natural ventilation or not. is 0.35 ACH independent of the current air tightness of a home or is it assuming a home o...