What You Should Know About Indoor Air Quality (Iaq)

If you have noticed that you or someone in your family is sick more often than in previous homes, allergies or asthma have worsened, you have an urge to open windows whenever they are closed, smells tend to linger in one part of the home, or dust builds up much faster in one part of your home, you likely have a problem with the indoor air quality (IAQ) in your home. Another way to look at it, if you think you have poor indoor air quality because you smell something suspicious, you are likely correct. Our noses are pretty accurate.

Introduction to Indoor Air Quality

Did you know that the air inside your home is frequently far less healthy than it is outside? Indoor pollutant levels are often 2-5 times worse than outdoors, and sometimes as much as 100 times worse, according to the Environmental Protection Agency (EPA).

Poor IAQ has both long and short-term health effects that have come under more scrutiny in recent years. Read on to find out why IAQ is a big deal now, what the various pollutants are, and what health effects can result. The solutions vary greatly by the home as well as the homeowner, so that part is discussed during the solution design process.

Where does bad indoor air quality come from? It’s pretty simple. Typical culprits include mildew, mold, cleaning products, pet dander and waste, pest infestations, cooking byproducts, radon, furnaces and water heaters that burn poorly and create carbon monoxide, and a number of other crummy things that are inside our homes.

IAQ also affects the noise, light quality, vibration, thermal comfort, and smells in your home.

Why is IAQ Such a Problem Now?

As buildings have gotten more air tight over the last 50-60 years, those culprits stick around longer than they used to in old houses, because they don’t leak out as quickly. Even in leaky houses these indoor pollutants can build up, especially in the spring and fall when our furnaces and air conditioners don’t run that much to mix the air. We also use a lot more man made products than we used to in buildings, so building materials, furniture, carpet, and other things bring pollutants in that weren’t used 50 years ago.

Our bodies are very sensitive to pollutants, so if in the spring you are dying to open the windows, there’s probably something in the house that needs to air out. We’ve found very consistently that when a homeowner thought there was a problem, there was.

Health Effects

Things like small particles, mold, radon, carbon monoxide, and other indoor pollutants have serious long and short term effects, but don’t take it from us, read about them from Green Guard, the EPA, or the World Health Organization (WHO). Short term effects can be lethargy, difficulty making decisions, sleepiness, and more. Long term effects can be allergies, asthma, various respiratory issues, shortened lifespans, and even cancer in extreme cases.

As part of our design process to fix your home from a comfort, energy, health, and durability standpoint, IAQ solutions are always offered in one or more solution packages we develop. We also offer testing if you think there is a problem to narrow down causes and help guide us to a solution. Here’s a list of various indoor air quality factors:

What’s the Solution?

If done correctly, home performance measures such as encapsulating crawl spaces, air sealing, duct sealing and dewatering can make the air in your home substantially healthier, but the solution needs to be designed specifically for your home; slapdash measures can leave the air crummy, or often worse because of air sealing.

IAQ affects not just the health and safety of your home; it is closely tied to energy efficiency as well. Homeowners often do unusual things to mitigate IAQ problems like open windows in winter and run bath fans too long, driving up their energy bills. Add to that cost of doctor visits, missed work and school, and medicine trying to treat the symptoms. Few realize that the root cause is environmental. Solving IAQ problems involves thought and often testing.

A Short Guide to IAQ Pollutants


CO2 has 2 factors. 1. Canary in the coal mine – when CO2 concentrations get high, it is a sign that the air inside a building is stagnant. 2. At high levels, it can severely reduce decision making ability, according to a Berkeley Laboratory study. The Air Advice monitor tracks this.


This comes from incomplete combustion. Basically, if your furnace, water heater, dryer, oven, fireplace, or other ‘combustion appliance’ is burning poorly, it creates carbon monoxide rather than carbon dioxide when it burns. It is thought to have health effects at very low levels, and very few actually measure it. Measurement of CO is part of a high quality energy audit, and the Air Advice monitor also tracks this. Ozone, nitrous oxides, and sulphur dioxide can also be related to combustion.


VOCs – Just call these chemical pollutants. They are chemicals that evaporate at low temperatures, meaning room temperature, so they go into the air. They also tend to be stronger when the humidity is high, like in a basement. Scented candles are, well, VOCs. New car smell and new furniture smell? Formaldehyde, a VOC. Lots of cleaners, solvents, and paints have VOCs. The Air Advice monitor has a general sensor for these, although it doesn’t tell you what chemical it is.


Very small particles, below 2.5 microns, are small enough to go right into your lungs and directly into your bloodstream. Particles 10 microns and under get into your body at least. Pollen is a big example, although that is typically a larger particle, as you can see it, and visible particles start in the 30-50 micron range. Diesel soot, ash from fireplaces, smoke, and road grime are other examples. At moderate and high levels, they have a strong effect on lifespan, according to the WHO. Even at very low concentrations, the WHO considers them a health risk. How do you know if it’s a problem? You measure.


While this is not truly a pollutant, high humidity levels contribute to a number of IAQ problems. VOCs are released much more quickly at higher humidity levels. Mold starts growing around 50% relative humidity, depending on the strain, around 65% there are very high odds it is growing, and at 80% and above it can multiply very quickly. Basements in damp climates (everywhere East of the Mississippi) typically run very high humidity and hence are prone to mold, mildew, rot, and other moisture problems. Controlling humidity inside a home is a key part of our process and leads to substantial comfort, durability, and efficiency gains as well as improved IAQ.

Foundation Waterproofing

Using Mar-flex 5000, we can waterproof any structure with an adhesive seamless barrier that coats your foundation with a high-quality membrane.

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Spray Foam Insulation

The spray application method allows for continuous insulation and an air sealing barrier on walls, roofs, in tight corners, and all contoured surfaces.

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Cellulose Insulation

Made of 75-85% recycled paper, cellulose is the most environmentally friendly and efficient way to insulate your new or existing residential or commercial buildings.

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Green Remodeling

Beyond energy efficiency, we’ll work with you on a number of eco-friendly building improvements that help you qualify for certifications such as LEED for Homes or ENERGY STAR.

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Fiberglass Insulation

Made of up to 40% recycled materials, fiberglass is available as blown-in loose fill, rolls, or batts, and is one of the best ways to reduce your energy bills.

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Radiant Barriers

In a climate such as Virginia’s, radiant barriers or “foil insulation” can be used in tandem with other materials to reduce cooling bills in the summer.

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Energy Audits

We’ll find the leaks and shortfalls of your current insulation, then provide a cost-effective plan that works for you and your project.

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Optimizing your building’s energy efficiency is one of the best investments you can make for comfort, lower bills, a reduced carbon footprint, and air quality.

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Crawl Space Encapsulation

Vented crawl spaces are no longer the way to go. Reduce excess moisture and prevent mold growth by isolating the crawl space from outside moisture.

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Mold Remediation

From the lab test to the mold removal to prevention systems, our whole-home approach to air quality ensures comfort and safety for your family.

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