Fresh Air and Energy Recovery

This project has an additional piece of HVAC equipment: an Energy Recovery Ventilator (ERV).  The pictures show the installed Renewaire EV-90.  It’s pretty simple, no moving parts…just filters to change!

A typical house has lots of air that leaks in through cracks, joints and other openings in its non-airtight envelope.  These drafts and leaks do provide a home with fresh air, but at a comfort energy cost to the homeowner.

On the other hand, a tight house needs fresh air brought into it and stale air exhausted from it.  An ERV provides this air exchange in a house.  The benefits of an ERV is that it preheats (or cools) outside air prior to having it enter the homes heating and cooling distribution system.  This pre heating (or cooling) saves significant energy.​

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It works like this…

In the summer, the ERV exhausts cool indoor air.  This precooled air is moves through the ERV and it transfers some of coolness to the warm incoming fresh air.  In the winter, the opposite happens; warm indoor air is used to pre-heat the incoming cold fresh air.  Along with the heating and cooling transfer, humidity is transferred as well.

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