Customizing Indoor Air Quality

Feature Article

Customizing Indoor Air Quality

why everyone in the design-build community should be advocates for clean indoor air.

By Steve Panosian

iPad and home ventilation diagram

Over the last few centuries the time spent outdoors versus the time spent indoors has virtually flipped. According to the Environmental Protection Agency (EPA), the average American spends 93 percent of their life indoors. The time spent indoors amounts to only one half of one day per week outdoors. It’s no wonder we generally feel happier when the sun is shining and we’re outside.

"We’ve gone from being an outdoor species to spending most of our time in dim, dark caves", per Russell Foster, Nuffield Laboratory of Ophthalmology, Oxford. Peter Foldbjerg, the head of daylight energy and indoor climate at skylight manufacturer Velux, said in a statement, “We are increasingly turning into a generation of indoor people where the only time we get daylight and fresh air midweek is on the commute to work or school.”

The Velux Indoor Generation report found that 80 percent of Americans are unaware indoor air can be five times more polluted than outdoor air and don’t realize that all that extended time indoors has a detrimental effect on our health and well-being, similar to poor diet or lack of exercise. The eye opener is that poor air quality in our homes, our offices, and our schools directly impact costly health problems like asthma, respiratory disease, heart disease and chronic obstructive pulmonary disease. Spending most of your time indoors and a lack of sunlight leads to lower brain function, sleep quality, mood and productivity.

But how does the air indoors get so bad? The air indoors is basically the same as outside air, with added pollution from all the materials around us. Anything from paint and cleaning products, to furniture and upholstery, to plastic toys and carpets, can trap dust and become a pollutant. Children’s bedrooms are often the most polluted rooms in the house.

Humidity, mold and inadequate temperatures can all lead to more pollution indoors. “When people are asked about air pollution, they tend to think of living near big factories or busy urban areas with high levels of car emissions,” Foldbjerg said. Because of these indoor air quality issues, we need to shift the way we view the home. We now need to consider the home as a “micro-environment” and control what we breathe and create an overall healthier environment.

Air quality benefits everything in the home, especially considering a home is made of wood among other materials prone to changing temperatures and humidity. It would be safe to assume that management of indoor air quality also improves the longevity of decorative materials, fabrics, carpeting, area rugs, artwork, and stored collectables.

In this series of articles on indoor air quality, we begin with the big picture – why everyone in the design-build community should be advocates for clean indoor air, known air quality issues, and how a passive home design with proper air filtering and air exchange mechanicals can significantly improve a home’s air quality along with all of the tangible benefits a healthy environment delivers.

just how do you customize indoor air quality?

Implementing a properly designed air purification system can provide a breathing environment dramatically improved versus outside air. Customizing the indoor air quality to meet personal preferences is also possible. Improvements that are most likely noticed when breathing in a healthy environment:

  • The flow of oxygen helps you digest food more effectively

  • Improvements in blood pressure and heart rates occur

  • Increased quality of oxygen in the air raises the level of serotonin, a chemical that has a wide variety of functions in the human body that among other attributes promotes a feeling of happiness

  • Strengthening of the immune system with increased white blood cell function

  • Cleanses the lungs, improves functional releasing of toxins

  • Healthy air lifts energy levels and raises alertness

These attributes will impact all ages, young and old. When you consider the lifestyles of the baby-boomers who may not be as mobile as they were when younger, indoor air quality can make a huge difference is one’s mood and general well-being.


“It’s a pretty wild approach to think that you could actually save the environment while having a better home.”

air quality issues

Wave Home Solutions of Long Island, NY list these examples of issues impacting air quality:

Moisture Accumulation – Everyday activities such as bathing, cooking, and washing laundry increase the moisture level. Basements and crawl spaces are the most moisture laden areas of the home as seepage from outside and lack of ventilation increases and traps moisture in these areas. They therefore contain the most problematic air mass in the home. That air mass makes its way into the upper areas of the home through natural airflow known as “stack effect.”

Gases - Vapors and gases from the ground are known to permeate through the foundation floor and walls in the basements and crawl spaces. This is the natural point of entry of radon gases and toxic vapors that seep in undetected. Combustible appliances such as furnaces, gas dryers, and water heaters can also leak harmful gases into the air.

Formaldehyde - Building materials, cabinetry, carpeting contain formaldehyde which is given off in a gaseous state and has a life span of 10 years or more.

Viruses – Viruses and bacteria from common health ailments and other sources pollute your home’s air allowing diseases to spread from one person to another.

Energy Efficiency – It is a scientific fact that it requires less energy to heat or cool a dry environment as opposed to a moist one. Energy efficiencies gained from building tighter homes will be lost if moisture accumulates and the HVAC system needs to work harder.

passive home design

Passive home designs are well-insulated housing envelopes coupled with air barriers, air sealing, and the use of heat exchangers to recirculate indoor air. Managing home air quality begins with airtight construction and requires a sophisticated air purification management system. The system can also address air quality challenges in specific zones like kitchens, bathrooms, basements, utility rooms and attached garages. Passive home design and an air purification system need to be carefully engineered to properly address the objectives for achieving a healthy home micro-environment:

Energy Efficiency - Passive buildings use 90 percent less energy for heating and cooling than the average existing building stock – to offer a proportional response to the climate crises. Note: despite widespread misleading descriptions to the contrary, most cold climate Passive houses are still required to have a heating system, it is just a very small heating system, and therefore likely not a traditional heating system. Nor is a Passive house necessarily a zero-energy building – it uses power, if much typically less – but it can more economically and readily become “zero-energy” with a relatively modest addition of renewables.

Affordable - Added construction costs for high performance are substantially offset by a reduction in systems sizing. Because the reduced energy use translates into lower bills and protection from future energy shocks, occupancy is affordable.

Predictable - An integrated methodology and energy model provides predictability – an essential element in optimizing system sizing and cost.

what makes up a whole home air purification system?

Air purification systems are not based on just one device. Regardless of the heating and cooling requirements of a home, to achieve the benefits of a passive home and manage a healthy home environment, a whole home system will likely be comprised of many different components and depend on the spec of a home and its geographic location. The system design will need to factor and address:

1. Ventilation – fresh air intake and exhaust

2. Air Exchange – energy capture management

3. Purification and filtration

4. Humidity Control – dehumidification and humidifying

5. Heating and cooling

While renovations can address energy efficiency, indoor air quality management needs to be carefully considered. This is where custom control and management comes into play.

Old homes can be full of charm, but no one will mistake them for being energy efficient. Especially when the heating and cooling bills arrive. "You've got these beautiful old homes, and they really perform horribly," says Michael Ingui, a partner at Baxt Ingui Architects. “They leak air, release heat and allow pollutants and allergens in. Many have bulky, noisy radiators that take up a lot of floor space.”

Playing into our opening point about the home needing to be viewed as a micro-environment, older home renovations are perhaps the greatest opportunity to help save the environment while having a better home. "You gain a better house," Ingui says. "You gain a healthier house. You gain money in your pocket for not paying for heating. It's a pretty wild approach to think that you could actually save the environment while having a better home."

final thoughts

Clean air and purified water should be engineered into every one of our homes. Unfortunately, that’s not happening. We will continue to address these issues and offer solutions. All design-build professionals should advocate for these basic necessities when working with clients on new builds and remodels. Stay tuned for more on how to create healthier indoor environments.