Home Energy-Saving Systems

Protecting Air Quality

In the absence of sufficient air exchange with the outdoors, indoor air can start to suffer quality problems. Odors from cooking and pets, off-gassing from building materials and furnishings, radon gas, combustion byproducts from gas ranges, and other pollutants can accumulate. Studies reveal that, because we spend approximately 90 percent of our time indoors, exposure to these items can be dangerous -- especially for children, seniors, and those who suffer from cardiovascular or respiratory diseases. The solution is to increase ventilation in order to dilute and exhaust the problem air. Below are some guidelines on how to improve the air quality in your home.

Turn on the Fan

One good way to reduce humidity and air pollutants is to attack the problem of poor indoor air quality at the source. Because bathroom fans reduce the level of indoor humidity by venting water vapor to the outside, be sure to turn on the fan when you bathe or shower. Also, turn on the fan to a kitchen range hood while cooking to vent odors and humidity. This is especially important when you use a gas range or oven. Gas ranges produce combustion byproducts that collect in the house unless vented.

Some range hoods, however, remove only gaseous pollutants like combustion byproducts when they vent to the outside, and many range hoods do not even do that. Recirculating-type range hoods are somewhat effective at removing airborne grease, but they do not take combustion byproducts out of the air.

Whole House Solutions

Air filters, either stand-alone or furnace-mounted, can be helpful in straining dust and dead skin cells (from both humans and pets) from the air, but they are not effective at removing gas-type pollutants.

One of the best methods of reducing the level and impact of indoor air pollutants and excess humidity is to mix the indoor air with fresh, dry air from outside the house. But after you've just spent hours and dollars trying to increase the airtightness of your house in order to make it more energy-efficient, how do you increase the ventilation without reducing the effect of everything you've accomplished?

It's hard to make an older home so airtight that indoor air pollution becomes a major problem -- or at least one that can't be solved by taking one or two simple steps to alleviate the condition. Old houses just have too many places where air can leak out (and outdoor air can be drawn in). You'll never be able to find and plug them all. Newer homes are generally more airtight from the start.

If your house feels stale, stuffy, or excessively humid, simply opening a door or window for a few minutes each day will replace some of the bad air with good air.

Homeowners with children may find that this procedure takes place naturally, as incoming and outgoing traffic continually pumps air in and out of the house. If you need to resort to occasionally ventilating by opening doors and windows, the heat loss will be minimal if you don't leave them open for too long.

For homes with chronic indoor air quality problems that can't be eliminated or reduced by manual ventilation and removing the pollutants and humidity at the source, other means are available to introduce fresh air to your home with minimal heat loss. Heat recovery ventilators (HRVs) use fans to continually bring air in from outside the house. As incoming air enters the HRV, it passes through a heat exchanger that is kept warm by the indoor air exiting the other side. Because the two air streams never mix, the only thing transferred from the outgoing air stream to the incoming one is heat. And while there is not a 100-percent heat transfer, the exchange is efficient enough that the incoming fresh air can be quickly warmed by the home's heating system.

An HRV can be installed either as a stand-alone system or tied into forced-air furnace ducting. The fans, used to pull in and push out the air, are small, but they do use some electricity. Filters can be added to the installation in order to clean the incoming air before it enters the house. An HRV installed correctly should be virtually unnoticeable to the homeowner. There should be little or no noise and the mix of incoming air with the air already inside the house should not create drafts or cold spots. An HRV can also be shut off when it is not needed.

In the next section, learn about alternative energy sources to power your home and ease your utility bills.