Passivhaus Pillar No. 5

Mechanical Heat

Recovery Ventilation (HRV)

The final pillar of passivhaus is Mechanical Heat Recovery Ventilation or HRV.

The reason that you need mechanical heat recovery ventilation, or HRV as we call it, in a passivhaus design, is due to a fellow pillar of passivhaus which is air tightness.

The house in this video has achieved 0.6 air changes per hour and so it has a heat recovery system installed.

The heat recovery system essentially, takes outside air pumps it into the house, and at the same time, passes it over the outgoing air that’s being drawn out through the wet areas.

The big thing to remember with heat recovery units is that they are not air conditioners and they are not heaters.

The HRV’s entire purpose is to keep the air inside the house fresh.

A lot of people have a misconception about passivhaus that you can’t open the windows.

That’s simply not true.

However, when you have a passivhaus, you are in control of the air temperature inside. Additionally, you are also in control of the quality of the air flow inside!

A HRV will remove harmful dust and allergens, it will dry the air in your home and give you air that is health and easier to breathe! 

Not only does a HRV make your environment healthier and happier, it doesn’t require as much additional energy to heat the air as you would a normally ventilated home!

If you want to know more about building a passivhaus, download our guide to the five key skills of a passivhaus builder.