Air Quality Issues: Ventilation and Humidity Control
Indoor air quality decreases as less outside air is introduced into a home. Because of the improved techniques in sealing homes for energy management purposes, ventilation is becoming an extremely important component in indoor air quality. Tighter homes resulting in less air transfer generally mean indoor air quality is affected negatively. If too little outdoor air enters a home, pollutants can sometimes accumulate to levels that can pose health and comfort problems. One successful approach to lowering the concentrations of indoor air pollutants in your home is to increase the amount of outdoor air coming in.
Outdoor air enters and leaves a house by: infiltration, natural ventilation, and mechanical ventilation.
Infiltration—is a process where outdoor air flows into the house through openings, joints, cracks in walls, floors, ceilings, and around windows and doors.
Natural Ventilation—is when air moves through open windows and doors.
Mechanical Ventilation—devices, from exhaust (vented outdoors) fans that intermittently remove air from a single room, such as bathrooms and kitchens, to air handling systems that use fans and duct work to continuously remove indoor air and distribute filtered and conditioned outdoor air to strategic points throughout the house. According to Lord, the most effective method of controlling air quality is through mechanical ventilation. It allows you to introduce fresh air and remove a good share of air pollutants when the air is exchanged. To determine if you have any indoor air quality issues you have to ask yourself some questions…Do you have excess dust, stuffy rooms, moisture on window panes or sweaty pipes, musty odors? Are there family members that often sneeze, feel lethargic, or have dry skin ? (Pollutants can sometimes accumulate to levels that can pose health and comfort problems).
Humidity Levels: Improving Your Home Healthfulness
In addition to ventilating, controlling the humidity level is a significant factor in air quality and comfort in general. In fact, industry experts state that keeping your home’s humidity between 30-60% can reduce the effects of many unwanted conditions. To determine if you might have an air quality issue as it relates to humidity, review the following symptoms often present with less than optimum humidity levels.
Too Little Humidity
- Physical symptoms such as sore throats, dry/itchy skin, nose bleeds or sinus irritation.
- Wood floors are shrinking and cracking. Joints in wood furniture are becoming loose or failing.
- Wallpaper is peeling, paint or plaster is starting to crack.
- Static shocks are common occurrences.
- Your thermostat is cranked up, as is your energy bill, but you still feel cold.
- Your piano and other musical instruments are falling out of tune.
Too Much Humidity
- Your skin often feels clammy, sweaty or sticky.
- Musty-smelling odors are invading your living space.
- Wood floors, trim or wood furniture are warping or rotting, paint is peeling.
- Condensation, frost or ice have formed on the inside surface of your windows. Water pipes are “sweating.”
- Damp spots, or worse, mold and mildew, have formed on ceilings or walls.
- Allergies or asthma have gotten worse due to the growth of mold, mildew and dust mites.
- Your house is a breeding ground for termites, cockroaches and other pests.
Of course, this is the time of year when moisture builds to uncomfortable levels. Here’s what you can do to treat the problem of too much humidity…
- Use ventilation fans in kitchens and bathrooms when in use. Ensure that your fans are venting directly outside.
- Cover dirt floor crawlspaces under your house with plastic to act as a vapor barrier.
- Check to make sure your dryer is vented to the outside. Don’t dry wet clothes on drying racks in the house. Air-dry them outdoors if possible.
- Ensure air conditioning drip pans are clean and drain lines unobstructed.
- Fix any water leaks in pipes, toilets, showers, etc.
- DEHUMIDIFY! Use a dehumidifier in addition to your air conditioner to pull out excess moisture that your air conditioner alone can’t handle.
There’s new technology out there for HVAC systems that can actually help with ventilation issues and with too much moisture at the same time. We recommend an installed, high capacity central dehumidifier which can convert to work in just your basement or throughout your home. This kind of system can also provide controlled fresh air ventilation, which means that fresh air can be brought in, but conditioned to reduce humidity before it enters the entire home. It’s a great double–header for comfort control! Central Dehumidification systems like this one from Aprilaire can handle up to 150 pints of moisture removal each day and can provide proper ventilation at the same time.
