Deep Breath: Preparing Your Home for Winter
Winter is upon us and often this is the most difficult time of the year for some homeowners because of poor indoor air quality. During the spring, summer, and fall, we can open our windows to let fresh air into our homes; but during the winter, we are energy conscience and close everything up nice and tight. The indoor air is recycled through the HVAC unit without the benefit of dilution from the outdoors. There are three central issues that affect the indoor air quality of a home during the winter. First, the potential buildup of debris that is created inside the home that is not removed or diluted. Second, gasses that enter the home in an uncontrolled manner. Third, proper attic ventilation that allows moisture to migrate outside the home.
The Heating Ventilation and Air Conditioning (HVAC) system that is used in most homes has a filtering method that cycles air through the supply and return air ductwork. When we cannot influence the indoor air quality by dilution from outside air, we depend on the filtering system to help remove the buildup of airborne debris that often happens in the home. This is important because studies have shown that one half of the dust that is found in a home are skin cells that we shed during our normal living activities. There are lots of small creatures that love to eat this high protein material. Their excrement is the number one cause of respiratory destress in a person that is not associated with microbial contamination.
The most common method of filtering is a fabric that is installed in the return air duct and directly in front of the fan that cycles the air. These filters are ranked for effectiveness with a MERV rating; the lower the number the less fabric and more open the weave, the higher number the more fabric and surface area to catch particles. A good quality filter for a residential home has a MERV rating or 11 or 12. Just be aware that the higher the number and more abundant the fabric, the greater the resistance to air flow through the filter. There could be such a pressure drop across the filter that the motor to the fan could overheat. The advantage to having a filter with a larger amount of fabric is because the way the filter works is by the particles impacting, and sticking, to the strands of the fabric. Many people feel particles are trapped between the weave, but that is not correct.
Another common method of removing debris from the air is using electric air cleaners. This filtration system ionizes the particles and then traps them in on the wire weave using an electrically charged field. This type of filtration is effective, but the filters normally need to be cleaned every 3 weeks. Check your owner’s manual for proper maintenance.
Gasses Entering the Home
Water that enters a drain can be a conduit for gas to enter the home unless the trap filled with water. These gasses can be of any organic or chemical that is put down a drain. To check the status of your traps, take some incense or anything that can create a smoke. Create a stream of smoke near each drain inlet and see if the smoke is pushed up from the drain rather than just flow across it. The upward flow of smoke indicates the drain is open to the main piping system and gas in entering the home. There could be several reasons for this, broken piping, improper piping installation, or a dry trap to mention a few. This must be addressed to prevent unwanted exposure to vapors that could be dangerous.
If you use gas combustible appliances such as a hot water heater, it is always wise to have a combustible gas indicator nearby the unit and a carbon monoxide meter. Natural gas that is supplied to homes has odor additives so you can smell a leak. But if these appliances are in the basement and you don’t go down there, you may not notice a problem. If you don’t have a combustible gas indicator, then you can call the local fire department or your gas supplier to confirm your home is safe. A carbon monoxide meter is available at any box store.
An average four-person family produces up to 4 gallons of water a day from cooking, showering, breathing, perspiration and all the other things we do as people. All this moisture must leave the home through the attic or be removed by a whole house dehumidification system. Proper attic ventilation is more important during the winter than the summer because of the ice build-up that occurs on the underside of the roof decking. Some properly vented attics still do not operate correctly during the winter because the homeowner does not heat the home to a high enough temperature. During the summer the sun provides the solar calories that heat the attic that causes the rise and evacuation of the attic air. But during the winter, the heat differential between the temperature in the attic and the outside is provided by the upward migration of heat from the home. Without this heat, the moisture will not evacuate, and it will build up in the attic which causes mold growth or structural damage.
Typical symptoms of a poorly ventilated attic are high humidity in the home, sweating on the
windows, mold growth on the personal contents and furniture.
Deep Breath is an article that is dedicated to distributing information through the Stark & East Central Ohio BIA newsletter. Hopefully the information presented here will spark your interest in learning more about a topic that will help your business and clients. If you have any questions or would like to hear about a certain topic, you can reach me at BobBennett@usefarsight.com. I will post some of the questions asked at the end of the next article.
Bob Bennett is the President of Farsight Management, and the President of the Indoor Air Quality Association for North East Ohio. He has been provided indoor air quality consulting and abatement for the last 20 years to builders, homeowners, insurance companies, and property management companies. You can follow Mr. Bennett on Facebook under Farsight Management; he frequently posts comments on interesting projects and articles of interest. Contact him through his email if you have any questions.