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"The connection between health and dwelling is one of the most important that exists."

— Florence Nightingale

Over the past year, interest in creating healthier homes with better indoor air quality has skyrocketed. If you've been searching for answers about how to improve the air quality of your home, you've probably come across a lot of information, advice, and products claiming to have the solution. It can be confusing and overwhelming to try to sift through it all — let alone determine what's trustworthy and what's not. 

Fortunately, you don't have to figure it out on your own. Pearl is here to help with reliable, unbiased, and science-driven information for health-conscious homeowners like you. Below we break down this complex topic to help you better understand the key elements that impact indoor air quality and what you can do to create a healthier home for you and your loved ones.

The Four Keys to Better Indoor Air Quality

When discussing indoor air quality, Pearl emphasizes four key elements:

  1. Prevention / Source Control: Stop pollutants from entering the home.
  2. Ventilation: Bring in fresh air to dilute pollutants, and remove stale air.
  3. Filtration: Filter your home’s air to complement your home’s ventilation system.
  4. Controls and Monitoring: Monitor, measure, and take action, as needed.

Let’s look into these in more detail.

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1. Prevention / Source control - Stop pollutants from entering your home.

Keeping pollutants from entering your home is your first defense when it comes to indoor air quality. In addition to the tried and true advice like not smoking, improving cleaning practices, and minimizing dust and pet hair, the following sources of pollutants are important for homeowners to be aware of:

  • Air leakage. Holes in a home’s shell exist in the attic, walls, windows, or foundation. Air sealing can reduce radon and other soil gases, outdoor pollutants including wildfire smoke, pests, and humidity (a common, serious and often underestimated problem).
  • Atmospherically drafted combustion appliances. Furnaces, boilers, and water heaters can spill carbon monoxide and other combustion pollutants into the home.
  • Leakage in ductwork. Improperly sealed return ductwork can draw contaminant-filled air from crawl spaces, attics, and other unconditioned spaces.
  • Improperly balanced forced-air systems. Over-pressurized rooms can lead to condensation that results in mold and mildew within the wall cavities. Under-pressurized rooms can do the same — as well as draw in contaminant-filled air from crawl spaces, attics, and other unconditioned spaces.
  • Bacterial growth on the indoor coil. Fungi and other bacteria can flourish in wet, cold places. UV lights can mitigate that contaminate source — as long as they do not generate ozone, which just adds another pollutant to the home.
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2. Ventilation - Bring in fresh air to dilute pollutants, and remove stale air.

Breathing, cooking, taking showers, opening doors, and simply using homes introduces contaminants into the indoor air. There is no perfect source control, but consistent with ASHRAE 62.2, Pearl encourages:

  • Spot (local) ventilation in rooms where activities introduce contaminants. Full bathrooms and kitchens need to have properly exhausted fans to remove excessive humidity. Cooking also introduces small particles, known carcinogens, smoke and odors. If the kitchen has a gas oven or range, byproducts of combustion gas are also introduced. Workshops and even garages also benefit from depressurization.
  • Whole-home ventilation. Delivering fresh air and removing stale air with a balanced ventilation system throughout the entire home is your best option. Even carbon dioxide is a pollution at high levels that causes fatigue and headaches. Whole-home ventilation mitigates the presence of virtually all pollutants (assuming the system is properly designed, installed and maintained). While not as ideal as a balanced system, supply-only or exhaust-only whole-home ventilation strategies are effective and less costly solutions to deliver whole-home ventilation.

3. Filtration - Filter your home’s air to complement your home’s ventilation system.

Filtration also plays an important role in protecting a home’s air quality. MERV-rated filters and electronic air cleaners filter out particles and, in some cases, even viruses. As with all IAQ solutions, proper design, installation, and maintenance is crucial. Proper airflow must be maintained, and a professional should measure static pressure drops to ensure the HVAC system’s health isn’t compromised due to a mismatch with the filter type. Visit Green Door, Pearl's free home management tool, to find a qualified IAQ contractor today!

4. Controls and Monitoring - Monitor, measure, and take action, as needed.

Smart Home Tech

A home is a very dynamic environment. External factors like temperature, humidity, direct exposure to solar, and the composition of soil gases and ambient air pollutants (pollen, smoke, etc.) can introduce pollutants into the home. Occupants use the home in a variety of ways that can also add contaminants. And a home’s materials and mechanical systems can either help or hurt indoor air quality.

So what’s a concerned homeowner to do? Well, knowledge is power. The ability to measure and control humidity might be the most important IAQ factor to know and address. Humidity is a little like Goldilocks — too little is bad and too much is bad. You have to get it just right. The Sterling Chart is a tool that demonstrates the importance of keeping to the middle of the relative humidity spectrum.

But humidity is far from the only indoor air concern that can be monitored and controlled. With smart home technologies, homeowners can better understand the air quality in their home and take appropriate actions. Indoor air quality monitors can be placed in kitchens and alert homeowners to turn on the exhaust fan.

How Does Pearl Support Better Indoor Air Quality for Homeowners?

Pearl Points

Pearl points are awarded for a variety of features — including the four key areas of source control, ventilation, filtration, and monitoring and controls — that contribute to better indoor air quality. The more upgrades you make to improve your home's indoor air quality in these areas, the more certification points you earn, increasing your chances of "leveling up" your Pearl Certification status (from Asset to Silver to Gold to Platinum)! Learn more about how Pearl's Certification System works.

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Education, awareness, and recommendations

The discussion of indoor air quality is complicated. The home is a dynamic system of systems. Pearl helps homeowners like you understand these complex systems and rewards you for investing in improvements to your home's performance.

While each home is different when it comes to indoor air quality needs, here are some general recommendations that apply across the board:

  • Choose 2-stage, multi-stage and variable capacity heating and cooling systems. Focus less on SEER and AFUE, and more on the ability of the appliance to perform well in a dynamic environment. The ability of a home’s heating and cooling system to regulate based on changing demand is as important for IAQ as it is for comfort and energy savings. The flip side of this recommendation is to generally avoid single stage equipment. However, if single stage equipment is selected, Pearl strongly recommends that blower door test results are factored into a full load calculation for the home. Improperly sized and selected single stage equipment can result in a variety of comfort, indoor air, and energy problems and shorten its lifespan. Single stage systems can be an affordable and appropriate solution when properly installed.
  • A well-qualified contractor is the best source for addressing IAQ problems in your home. Pearl’s recommendations represent best practices and are broadly applicable to many homes. But a well-qualified professional’s recommendations are the most appropriate source for specific solutions based on the specific issues and needs of a particular home and homeowner.

Pearl aims to be your trusted third-party source for information on high-performing homes. Our website, blog, and new Green Door app are all great places for you to learn more about your home's performance and how you can create a healthier, more comfortable and efficient home.

Here are some additional resources for you to explore right now:

We truly wish you all the best in achieving your home health and air quality goals. Feel free to contact Pearl if you need additional support — and be sure to stay in touch and "in-the-know" by signing up for our Homeowner Newsletter below!

Looking for a qualified IAQ contractor? Log into Green Door to find a Pearl Contractor today!

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