Insulation and Air Quality: ERV
What is an ERV?
One of the main advantages of a well-insulated and well-sealed building envelope is that it takes less energy to heat and cool the home. An efficient building envelope keeps the conditioned air within the home that needs a smaller furnace and/or air-conditioner that is working less often — and this translates into real savings on the utility bills.
But when a home is well sealed a new problem arises — the home becomes a plastic bag, which means any pollutants, such as dust, that may get in the home “stay” in the home. To solve this particular problem, the home needs to be ventilated, and this is where an ERV — energy recovery ventilator — comes into affect.
An ERV pulls in outside air and exhausts the stale air from inside the home, and it does this in an efficient way by using the “exhausted” air to condition — or heat or cool — the incoming fresh air. For example, during the heating season the cold outside air is being tempered with the indoor air via the ERV and, therefore, you’ll be saving a good deal of heated air. The reverse is true in the cooling season.
Today’s tight homes seal in more than you think. With advancements in insulation, whole-house wraps, airtight doors and windows, the indoor air quality of you home can suffer. Without the circulation of fresh outdoor air, moisture and indoor pollutants continue to build up in your home. The EPA ranks indoor air pollution as one of the five most urgent environmental issues in the United States. In Canada, building codes already require Indoor Air Quality systems for all residential construction.
Indoor air quality systems mostly come in 3 versions depending on your needs.
- Energy Recovery Units (ERV)..designed for year-round air use. The ERV unit continuously introduces fresh air from the ouside while expelling stale air from inside. This is done without compromising your home’s energy-efficiency. In heating season both the incoming cool air and the outgoing warm air pass through an enthalpic core, where substantial heat and moisture recovery occur. The incoming air is basically heated by the outgoing air and then introduced to your home. In cooling season, the reverse occurs as the warmer fresh air if cooled by the cooler outgoing stale air.
-Heat Recover Units (HRV)..designed to be used during the heating season. The HRV unit uses a polypropylene core to recover heat from stale outgoing air and transfers it to the fresh incoming air. It is designed to remove excess moisture build-up in your home and prevent potentially costly problems from excess moisture.
-Air Exchanger (AE)..designed to reduce moisture levels over time by steadily pre-mixing warm inside air with incoming cold air before it’s introduced into your home.
It is very much desirable that Your home should be energy efficient and comfortable during the changing season all-year round.
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