HRV/ERV: Energy/Heat recovery ventilation:
Whether natural or mechanical; homes need ventilations.
As a new existing home. HRV is strongly needed- not only it injects the fresh air to indoor, but also it can filtered the incoming air with adjusted temperature, very efficiently.
Energy star sign on HRVs is a very crucial and in some ways is showing the efficiency, rate.
The amount of fresh air is needed at home (indoor) is very important too, and depends on how much air tight the home is we can choose our HRV, OR ERV.
Energy recovery happens from exhaust air in cold season and cold region especially both ERV/HRV RE DOING AIR CIRCULATION
Why air circulation is essential at home?
Since our old houses were not air tight – air had natural circulation and moisture was balance some how
But todays houses are really so tight to save better energy, then we won’t have natural air circulation , then we have to put a positive pressure to push the air somehow to make a ventilation at the same time balance the moisture .
We all know moisture affect temperature, and when somewhere have moisture our body prefers to breathe from our skin not nose
So, if we leave moisture indoor, Germs, bacteria, and even molds will grow.
HRV is an equipment that heated the fresh new incoming air with the temperature of exiled flue, that saves lot of money and reduces the energy required to adapt the outside temperature with indoor.
How to choose?
It depends on the climate and the house location, and also what kind of apparatus you have indoor
For example if your house is too humid in cold season HRV is better, which acts better in humid houses, than ERV
But in summer the use of HRV increase the humidity, so ERV is better
But at the end there is not a right choice in general, always it depends on the environment