Mr. Duct - Indoor Air Quality FAQs

Common Indoor Air Quality Questions and Answers

All of us face a variety of risks to our health as we go about our day-to-day lives. Driving in cars, flying in planes, engaging in recreational activities, and being exposed to environmental pollutants all pose varying degrees of risk. Some risks are simply unavoidable. Some we choose to accept because to do otherwise would restrict our ability to lead our lives the way we want. And some are risks we might decide to avoid if we had the opportunity to make informed choices Indoor air pollution is one risk that you can do something about. The following information was accumulated by the Environmental Protection Agency (EPA), the World Health Organization (WHO), and the US Consumer Product Safety Commission (CPSC) in the aim to better educate the public on Indoor Air Quality (IAQ) concerns.

We encourage all homeowners concerned about their home's IAQ to consider air duct cleaning as just one of the ways to improve your home's air. Reducing the use of dangerous chemicals as well as properly maintaining appliances that can emit harmful by-products is also a must.

For further questions, give us a call today at (888) 467-3828

Why Should I Be Concerned About Indoor Air Quality?
According to the EPA’s booklet on IAQ, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities.

Other research indicates that people spend approximately 90 percent of their time indoors. Their conclusion is that because of these factors, health risks may be greater due to air pollution indoors than outdoors.

Additionally, groups who may be exposed to indoor air pollutants most often are usually also the most susceptible to the effects of indoor air pollution. These groups include children, the chronically ill, and the elderly. Those who suffer from respiratory or cardiovascular diseases must be especially wary.
What is a Programmable Thermostat? What are its Benefits?
For families that are always on the go, programmable thermostats are a must. Programmable thermostats allow you to set your system at different temperatures throughout the day. This means reduced energy use throughout the day! Installing a programmable thermostat is a great way to start saving energy and money while you’re family is away or sleeping.
Why is the upstairs hotter in summer & cooler in winter when I only have one unit? What should I do?
Heat rises, thus the reason it’s hotter in the summer. Assuming the system was sized and installed correctly, you should consider installing a zone system if possible. Zoned thermostat systems allow you to control the amount of heating/cooling by home zone, meaning greater control of your home comfort. Sometimes the addition of return air ductwork will help improve air movement and help make upper levels more comfortable.
What Is a UV Light? What Are its Benefits?
UV is the abbreviation for ultraviolet. Located in the return air ductwork and by the indoor cooling coil, the ultraviolet air treatment system continuously emits high – intensity ultraviolet (UV) energy. The energy eliminates (kills) a very high percentage of airborne bacteria and germs passing over the UV light field inside the ductwork. The UV light mounted next to the indoor cooling coil will help eliminate the growth of mold, mildew and other contaminates from the drain pan and coil surface.
How Do I Improve Humidity Levels In My Home?
Poor equipment operation, inadequate equipment, and leaky ductwork can cause the air to be too dry in the winter or too humid in the summer. To address the problem of Illinois humidity, Mr. Duct offers several Trane® fan-powered and bypass humidifiers.

As we heat our homes, the air has a tendency to dry out. This dry air can damage the woodwork and furniture you have in your home as well as zap the moisture from your skin. Dry air even makes you feel cooler because your body senses heat as a combination of temperature and humidity. Adding humidity to offset this drying process will improve your comfort as well as preserve the woodwork in your home. As an added benefit, you may actually be able to lower your thermostat a couple of degrees. You will not only feel warmer but you may actually lower your heating bill!
What Causes Indoor Air Problems?
According to the EPA, most indoor pollution sources occur from using materials ""that release gases or particles into the air" ( They go on to specify a range of pollution sources as listed below:
  • Combustion Sources: oil, gas, kerosene, coal, wood, tobacco products
  • Building Materials & Furnishings: deteriorated, asbestos-containing insulation, wet or damp carpet, and cabinetry or furniture made of certain pressed wood products
  • Household Products: cleaning and maintenance products, personal care products, or hobbies products can contribute to poor indoor air quality as well
  • HVAC Systems: Improperly maintained central heating and cooling systems and humidification devices
  • Outdoor Sources: Radon pesticides and outdoor air pollution
Some sources, such as building materials, furnishings, and household products like air fresheners, release pollutants more or less continuously. Other sources, related to activities carried out in the home, release pollutants intermittently. These include smoking, the use of unvented or malfunctioning stoves, furnaces, or space heaters, the use of solvents in cleaning and hobby activities, the use of paint strippers in redecorating activities, and the use of cleaning products and pesticides in housekeeping. High pollutant concentrations can remain in the air for long periods after some of these activities.

Another cause to poor IAQ is inadequate ventilation and the introduction of fresh air in the home. It is important that fresh air be introduced into the home so that it can "dilute emissions from indoor sources". High temperature and humidity levels can also increase concentrations of some pollutants, like mold.

How dangerous these sources are depends on how much of a given pollutant it emits and how hazardous those emissions can be. In some cases, factors such as how old the source is and whether it's been properly maintained are significant: an improperly maintained furnace can emit significantly more carbon monoxide than one that is properly cared for.

The EPA holds that "solutions to air quality problems … involve such actions as: eliminating or controlling the sources of pollution, increasing ventilation, and installing air cleaning devices" (

If you fear that the common contaminants hosted in the debris of your air duct system is causing IAQ problems for your home, Mr. Duct's air duct cleaning service can remove these contaminants, as well as provide visual confirmation of our results.
Findings of the World Health Organization (WHO)
The World Health Organization (WHO) also published a report discussing indoor air quality, specifically focusing on the adverse health effects that occur when dampness and dirt contaminate the home. The report establishes that HVAC system components play a major role in the perceived indoor air quality of a home. They link the dirtiness of heating, ventilation, and air-conditioning systems with an increase of multiple respiratory symptoms and specifically mention, "dirty ductwork, dirty filters, and dirty air intakes" as pollutant sources.

The following are some of the many conclusions drawn in the document:
  • Evidence from sufficient research shows that occupants of moldy buildings are at increased risk for developing respiratory symptoms, infections, and asthma. Results show that remediation of dampness and mold can reduce adverse health outcomes
  • Clinical evidence shows that certain microbials related to dampness may increase the risks of rare health conditions
  • Common indoor dust and dirt provide sufficient nutrients to support extensive microbial growth
  • Persistent dampness and microbial growth on interior surfaces and in building structures should be avoided or minimized, as they may lead to adverse health effects
  • Remediation of the conditions that lead to adverse exposure to poor health in populations who are already living with an increased burden of disease
Further Research & Source Documents
Source Document:

EPA's Office of Radiation and Indoor Air's Inside Story: A Guide to Indoor Air Quality:

World Heatlh Organization (WHO) Dampness and Mold

Further Research:

EPA's Office of Radiation and Indoor Air's Care for Your Air: A Guide to Indoor Air Quality:

World Heatlh Organization (WHO) guidelines for indoor air quality: selected pollutants

The US Consumer Product Safety Commission's The Inside Story: A Guide to Indoor Air Quality:

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