How to improve indoor air quality
Indoor air quality, or “IAQ”, is a term often used to describe the relative pureness or cleanliness of the air within a residence or commercial structure. According to the EPA, “Indoor Air Quality (IAQ) refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants”. Air that circulates inside of a home can be unhealthy, and According to the National Institutes of Health, indoor air pollution may place greater risk on at-risk individuals than outdoor air pollution. A proper IAQ assessment involves air sampling, radon measurement, interpretation of results and an inspection of the foundation, plumbing, HVAC system and other areas of a home. Many factors can be used to describe IAQ, and there’s no standard unit of measurement of indoor air quality. Before I explain some of the ways to improve air quality, let’s dig a little deeper into what air quality means and some of the ways to find out if yours is poor.
Common contributors to bad indoor air quality
Industrial Pollution entering the home
Chemicals from synthetic flooring, paint, and insulation
Chemicals used in wood binding products in cabinets and structural wood
Mold
Pollen
Radon
Mildew
Fungi
Tobacco smoke
Vaping
Contamination from methamphetamine production
Carbon Monoxide
Household cleaning products
Personal care products
Cockroaches
Dust mites
Dust
Byproducts of rodent infestations
Air freshener products
Wood burning
Viruses and bacteria
Pet dander
Dust from woodworking
Exhaust from vehicles stored in attached garages
Scented candles (using unnatural scents)
How can indoor air quality be worse than outside air?
Houses, townhomes and condos can be closed ecosystems where air isn’t always exchanged freely with the outdoors. Besides the indoor air pollutants themselves, there are a few other issues that can make IAQ worse than the air outdoors:
Airtight and closed-up houses
Starting in the 1970’s or so, residential construction standards and materials used were introduced which had a positive impact on energy efficiency. A few of these changes included vapor barriers in walls, windows with air infiltration ratings and the more common usage of poured concrete foundations. In more recent years, testing of many newly constructed homes for air tightness is required as part of the code inspection process. This increased air tightness improves the efficiency of heating and cooling systems, but at the same time it can help create conditions for mold growth, and can trap other air pollutants. It may also lead to higher radon concentrations within a home.
Insufficient ventilation
Bathroom and kitchen ventilation fans are important to reducing humidity in homes. High humidity is one of the ingredients required for mold growth, so keeping it down is important for IAQ. A side benefit of these ventilation systems is that they also remove other odors from the house, and they can reduce levels of other indoor air pollutants.
We recommended that every bathroom has an exhaust fan that sends air fully to the outside wall of the house (not to the attic). Kitchens should have a range hood that likewise exhausts air to the outside. It’s typical that kitchens are equipped with a recirculating fan, sometimes built into the microwave. This type of fan does filter the air, but it’s far better to exhaust kitchen air to the outside of the house.
Damp basements
During home inspections of houses that date from the 1960’s back to the beginning of time, expect to find a basement that feels damp and dank. The foundations on these houses typically weren’t built with adequate (or any) perimeter drain systems, and the quality of concrete used seems to be a little more porous than foundations built in modern times. In these basements commonly found are damp areas of the foundation from the slab to maybe 2-3’ up the wall. Many of these foundations have mold growing in the damp areas. In many of them, the telltale “fruity” smell of mold can be detected, which sometimes goes along with a high mold concentration in the air. Many times, a small dehumidifier can be found in a corner of these basements. Unfortunately, these things aren’t nearly big enough to make a difference. It’s often recommended to have a high-quality dehumidifier system installed. Systems like this are sized to remove enough moisture from the air to make a difference, and they include ductwork and a permanent drainage system.
Hidden plumbing leaks
Plumbing leaks are usually found quickly by homeowners, but in some cases, leaks can be hidden behind walls and can go undetected for many months (or longer). The leak might be very small and cause a slow drip to find its way to a basement.
These leaks under the right conditions can allow mold growth to take off and can be catastrophic in the wrong situation.
Generally Bad Airflow
Boilers and radiators are still used as the primary residential heating source in many homes. People like these hydronic heating systems because of their perceived comfort, but a big downside is that air isn’t moved around the house, and air filtration systems can’t be used in the same way as with central heating and air conditioning systems. Keeping a few windows in a house is a good way to introduce fresh air into the home, and to allow some unwanted indoor air pollutants to escape.
It’s recommended that high-quality air cleaners are purchased for homes that don’t use central air systems.
What are some of the health impacts of low indoor air quality?
In cold climates you might spend more than 12-15 hours a day inside your house. The quality of air inside your house can have a huge impact on your health. Health effects of bad indoor air can vary wildly. Radon has been implicated in causing lung cancer in some individuals, and according to the US EPA, exposure to radon is the second-leading behind cigarette smoking.
Carpets, rugs, furniture, and curtains can hold pet dander, pollen, dust, and other allergens, leading to various allergic reactions.
Mold can be contained in basements, walls, carpet, and drywall throughout a house. Mold is a fungus that in some cases can be a mycotoxin, and in the worst cases can cause permanent brain damage. Various chemicals found in some building products, air fresheners candles and other chemicals can cause undesirable effects in many individuals.
How to determine if your IAQ is poor?
There unfortunately isn’t a single test or device that can instantly determine if the air inside of your home is “healthy”. If you would like to determine if your home’s indoor air quality is at risk of affecting your health or well-being, there are a few approaches to consider:
1. Have a qualified mold testing company near you collect air samples. Air sampling involves running a specialized pump that deposits particulate matter from the air onto a special cassette, that is then analyzed by a lab. A detailed report will then include qualities and descriptions of mold spores, insect parts, pollen, and other allergens.
2. Have a radon test performed in the home.
3. Assess any storage areas for volatile organic compounds, or “VOCs”. VOCs can include paints, stains, thinners, adhesives, and many other chemicals. If you have a large quantity of these materials stored in your home, then chances are good that they are reducing the quality of air in the home. At a minimum, avoid storing VOCs in basement areas. Ideally, don’t keep excess paints after they are needed.
4. Make sure that carbon monoxide (CO) detectors are installed throughout the home.
5. Consider installing air quality monitors in the house
What are ways to improve indoor air?
Air quality inside of a house can be worsened by lots of things, and therefore there are lots of ways to improve it. How can IAQ be improved?
Remove the pollutants from the air, or kill them
Install an air purifier
Install a MERV-11 or MERV-13 furnace filter, if your furnace can work with them
Grow indoor plants
Install an ultraviolet filter in your HVAC system, and replace the bulb annually
Improve ventilation
According to Harvard Health, “Stale indoor air and heating systems can increase the amount of allergy-inducing dust mites, pet dander, and mold spores circulating through your house”. So, how can ventilation be improved?
Make sure that kitchen and bathroom fans are operating properly and venting to the outside. Install timers on bathroom fans.
Check your clothes dryer vent to make sure it’s connected to an outside vent (not to the attic), and check the vent every few months to make sure it’s not clogged with lint
Open windows for short periods of time daily, especially in the winter
Install a heat-recovery ventilator (HRV). This system pulls in outside air in the winter and heats it
Eliminate Sources of Bad IAQ
Remove any sources of moisture
Have all mold removed professionally
Vacuum carpets and rugs on a regular basis, using a HEPA-rated vacuum cleaner
Clean bedding
Clean curtains and window coverings
Replace carpets with true hardwood floors
Remove decorative gourds or other organic material
Switch to leather or wood furniture
Toss fruit and vegetables before they go bad
Clean off the top of cabinets and refrigerator often
Don’t overwater plants, but consider that plants can actually be good for IAQ
Use a dehumidifier in your basement if it’s damp. Consider a professional-grade one.
Don’t smoke or vape inside of the house
This should be common sense, but cigarette smoke contains carcinogens and other chemicals that will collect in flooring, walls, ceilings, and any other semi-porous surface in the home. These chemicals may leach into the breathable air for years to come and may negatively affect the health of those living in the home. The ingredients in vaping liquid are unregulated and big questions remain about any health effects of them. My recommendation is to only vape outside, if it must be done.
Switch to natural cleaning products
In my opinion, it’s not worth the risk and the couple dollars to use chemical-laden cleaning products in the home. It’s well known that artificial fragrances and other ingredients that are contained in some mainstream cleaning products can induce unhealthy reactions in some people. My mother-in-law falls into this category.
Avoid Ventless Gas Fireplaces
Ventless gas fireplaces are gaining popularity by builders and remodelers due to their ease of installation. By definition they don’t need a vent to the exterior of the home, which reduces installation cost and labor. But their ventless nature introduces two variables:
1. If the balance of air inside of the home isn’t right then combustion within the fireplace will be incomplete, causing carbon monoxide (CO) to be discharged into the livable area of the house.
2. Water vapor is a natural byproduct of combustion. So humidity will be introduced into the home.
To avoid the risk of carbon monoxide exposure and increased humidity, have a vented fireplace installed instead. At the very least, install a short-term carbon monoxide detector near the ventless fireplace.