Perfect Weather…What’s the Problem?
Something I think about a lot..especially on days when the weather outside is perfect, oddly enough is “indoor air quality.” Here’s why..
So we build super tight houses these days with energy efficiency being under such a microscope. Everyone wants to save money. But, most of the time, we don’t think of the latent consequences. What I’m getting at is, a lack of fresh air inside our houses during Spring time..
Most older homes easily have a leakage rate of 35% per hour, but newer homes(especially ones built in the last 10 years) can have a leakage rate of less than 10% per hour. Anything under 35% requires a fresh air intake (basically a damper that allows fresh air from the outside so many minutes per hour..lets say 15 minutes or so). OK..so what’s the problem??
The problem is that when we don’t run our HVAC system (like when the weather outside is perfect), we don’t get enough fresh air in our home. That means we are REALLY trapped inside with all of the materials in our home(some brought by the builder and others brought by the occupants). We are talking VOCs: plywood laden with urea formaldehyde, paints with plasticizers and formaldehyde..same with stains, carpet with petroleum and fire retardants and stain blockers, nail polish removers, colognes/perfumes, hair sprays, cleaners with god knows what… Anyhow, you get the picture!! TRAPPED!!
So what to do?? Open your windows!! Bring that fresh air inside. But, if you are not a window person(due to allergies or humidity discomfort), than I recommend that you continue to operate your HVAC equiptment even during perfect outdoor weather. IF(and only if..) you have a fresh air damper on a timer, you can accomplish this by simply using the “fan” mode rather than “AC” or “Heat.” IF your system is set up to filter the pollen from the fresh air(via a media filter MERV 9 or higher) than you should be golden! Regarding humidity, a dehumidifier can help you maintain a relative humidity of around 50% (which is optimal to most people’s comfort standards) without operating your compressor/condenser which uses more energy than a simple dehumidifier.
Increased levels of humidity dramatically increase the release of toxins and VOC’s in the air, basically because humidity is the first step to breaking something down to its original form.
Don’t let your home put you in a funk or make you sick. Have a strategy to maintain clean indoor air during the entire year, not just when your HVAC equipment is normally in use. And do your best to minimize the use of poisons inside your house. Think before you build(builders), and before your spray(occupants). Just something that’s been on my mind lately, and felt inclined to share.
PS: Designers/Architects, find out whether or not your clients are “window people”, as the answer should have bearing on your collective strategy for maintaining optimal indoor air quality year round.
Doug Cameron is a Healthy, High-Performance Builder & Remodeler with EcoSafe Spaces, LLC in Austin, TX.