Cold weather brings dry homes. And dry homes bring itchy skin, scratchy throats, and irritated sinuses. To counter the effects of “dry house syndrome, " the first thing homeowners and contractors often reach for is a central humidifier.
If you happen to be an admitted germ-phobe, central humidifiers aren't for you. Think swamp-environment. That's the best way to describe the conditions inside your furnace-attached humidifier; a breeding-ground for bacteria, viruses, and molds.
If you have leaky ducts that run through an unconditioned area, such as the attic, warm “humidified" air is able to escape and condense on the cold roof-deck, causing costly moisture-damage and/or rot.
If you want to maintain comfortable winter humidity levels (+-40 percent RH), here's a more “holistic" approach:
1. ) Reduce your homes air-leaks. Cutting the homes air-infiltration rate reduces the amount of moisture that gets lost to the outside. Reducing air-leaks also reduces drafts and saves energy.
CAVEAT: In our opinion, there's no such thing as an “overtight" home. That said, if you don't have adequate ventilation, excess moisture can be a problem in tight homes. Additionally, overtightening the home in a manner that seals-off a furnace’ or water-heaters source of combustion air increase the risk of back-drafting the chimney and introducing carbon monoxide into the home.
2. Consider an energy-recovery ventilator (ERV). ERVs like their close-cousin, the heat-recovery ventilator (HRV), are ‘balanced’ ventilation systems. Conventional exhaust-only ventilators (i. e. standard bathroom fan) get their make-up air by pulling it through the cracks and leaks in the home. Not a very well-controlled method, and certainly not the best for indoor air quality.
Balanced ventilators, like ERVs and HRVs, bring fresh air into the home by way of dedicated ducts. As an added bonus, HRVs ‘recover’ a portion of the heat that normally gets exhausted and returns it back inside the home, a nice energy-efficiency feature. ERVs have an added-added bonus. They recover heat AND humidity and help keep clean, fresh-air circulating through the home without drying-it out in winter. Controls prevent the unit from causing excessive humidity-levels that can lead to condensation build-up on windows, or more serious moisture problems.
Balanced ventilators, like ERVs and HRVs, also help minimize the risk of chimney back-drafting. Some models have built-in HEPA filters for even better indoor air quality.
You'll have to spend more money in the short-term, but the benefits of this two-pronged approach are multi-fold - cleaner air, a safer home, lower energy bills, and greater comfort. And believe us, the goopy, sticky stuff that's sticking to the bottom of your humdifier is nasty.
John Bishop is vice president of Enhanced Living, Inc. , heating, cooling and indoor air quality specialists based in the Albany, NY-area. Extensive experience in the field of building science and residential energy-management, John was formerly the state marketing coordinator for New York's award-winning Home Performance with ENERGY STAR and New York ENERGY STAR Labeled Homes Program. John can be contacted at firstname.lastname@example.org .