Need fresh air in your home? Look at an ERV or HRV

Because today's homes are built "tight"  -   pollutants are trapped indoors and can concentrate to harmful levels.   The health hazards from indoor air pollutants are broadly recognized as one of today’s top environmental hazards.  An ERV (Energy Recovery Ventilator) or HRV (Heat Recovery Ventilator) can help expel contaminated air and bring in fresh air.  These ventilation products and also protect your home from extremes in humidity
 

Consider these 2 statements

1). The easiest way to bring fresh air into your home is to open a window
2).  The easiest way to remove stale air is to turn on a fan (like a bathroom fan)

Obviously you don't want to open a window on a frosty winter day in January or a blistering hot day in July.  This would make for a huge utility bill.  Turning on a fan to exhaust stale air outdoors doesn't make much sense - as you are removing air you have paid to heat or cool.

Is there a way to get fresh air, expel stale air - and not dramatically impact your energy spending?  YES - this is what an HRV or ERV does.

HRVs and ERVs use internal fans to pull fresh air into your home and pull out stale air at the same time.  The magic to this is in the "core".   The core is a special chamber in the center of the HRV or ERV that air passes through.   Exhausted stale air and the fresh ventilation air pass through multiple air passages in the core separated by an engineered material (aluminum or plastic). Sensible heat transfers from the warm to the cool air stream. The fresh incoming air is automatically pre-heated or pre-cooled depending on the season. This dramatically reduces the energy costs of ventilation.

So, what's the difference between HRVs an ERVs?

Heat Recovery Ventilators (HRVs)
An HRV is designed to bring a continuous supply of fresh air into a home while exhausting an equal amount of contaminated air. HRVs use what is called a “sensible” heat recovery core. This special aluminum core transfers heat from the exhaust air stream to the incoming air stream. Fresh incoming air is tempered by the heat that is transferred from the outgoing air so you save on energy costs. Most HRVs are equipped with automatic defrost mechanisms so even if you live in the coldest climates you can use your HRV all year long.

Energy Recovery Ventilators (ERVs)
An ERV works much like the HRV but it is designed with a different type core. The enthalpic core at the center of the unit transfers heat and moisture from the incoming air to the outgoing air. The air brought into the living area is cooled and the humidity is reduced for maximum comfort. The load on your air conditioner is less and you save on cooling costs.

ERVs and HRVs can be installed as a stand-alone system with an independent network of ducts reaching into strategic areas in the home.  It is also possible to trunk the HRV or ERV into your central HVAC air handling system by tying ducts into the central cold air return.

Installation of an ERV or HRV should be left to a professional installer - but is not outside of the rhealm of an experienced Do-It-Yourselfer.