Homes are being built air tight for maximum eﬃciency and heat retainment. Because your home is built air tight, the air you breath is being recirculated through your lungs, the furnace, and other mechanical workings of the home.
Since all buildings require a source of fresh air, the need for HRVs (HeatRecovery Ventilation systems) has become obvious. HRV introduces fresh air into a building and improves climate control, whilst promoting eﬃcient energy use.
Bathroom fans and hood fans all have required ventilation codes to adequately and efficiently vent them. All fans come with a CFM rating on them to tell you what sort of air you are moving from your bathroom or kitchen to the outdoors.
Most systems out there are undersized and under designed by at least 50% causing unnecessary noise and a lack of air movement. Make sure you are getting the most out of the equipment being installed.