Indoor Air Quality

Although many people associate pollution and poor air quality with the outdoors, is air quality better indoors? The answer is it depends. Indoor Air Quality (IAQ) plays an important role in your general health and well-being, as well as the comfort of your home. Research has suggested that the air inside buildings might be more contaminated than outdoor air. Having clean air circulating throughout your home can reduce allergy symptoms, prevent viruses, kill bacteria, and help you breathe easier on a daily basis.

Since you most likely spend more time indoors than outdoors, the quality of the air in buildings, such as your home, should be something you consider. The good news about indoor air quality is that you have more control over it than you do with the outdoor air quality. While you might not have the means to go around and eliminate all of the sources of indoor air pollution, you can make a few changes to your home to improve the quality of the air you breathe.

What Is Indoor Air Quality?

Indoor air quality is the quality of the air inside of a building, such as your home, your office or a retail establishment. Indoor air quality is different from outdoor air quality as well as from air quality in an industrial setting, such as a factory or power plant.

Multiple factors can affect the quality of the air inside your home:

  • Temperature
  • Humidity levels
  • Ventilation
  • Chemicals and particles in the air
  • Mold growth
kid sneezing because of allergies

Did you know: The air in your home can be up to 5 times more polluted than the outdoor air?

The quality of the air inside of your home where you spend a lot of time can have a considerable impact on your health. Often, the health issues that result from poor indoor air quality are called “sick building syndrome” (SBS). The signs of SBS usually clear up once a person leaves the building.

What is Indoor Air Quality?

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What Causes Poor Indoor Air Quality?

A variety of factors influence the overall air quality inside of a building. Some of the causes of poor indoor air quality include:

What Are the Most Common Indoor Air Pollutants?

The types of pollutants that affect indoor air quality can vary based on what’s inside of a home or building and what can get inside of a structure. Although there is a long list of pollutants that can impact the quality of the air inside your home, if you do have poor indoor air quality, it is likely that one or more of the following is to blame.

The most common indoor air pollutants are biological contaminants, carbon monoxide, formaldehyde, tobacco smoke and volatile organic compounds

Biological Contaminants

Multiple pollutants fall under the category of "biological contaminants." What they have in common is that they come from a living source. For example, mold and bacteria are two examples of biological contaminants. Pet dander and saliva can also contribute to reduced indoor air quality, especially if you have allergies. The droppings and urine (which can become airborne when it dries) produced by cockroaches, mice and other household pets also fall into this category.

Certain conditions inside of a house can create an environment that's hospitable for biological contaminants. Damp or wet areas can lead to the growth of mold, bacteria and mildew and dust mites also thrive in wet or damp conditions.

Keeping the humidity levels in your home between 30 and 50 percent is one way to reduce the risk of pollution from biological contaminants. Controlling any pests, such as by catching mice or roaches and by keeping food and water out of their reach can also help.

Carbon Monoxide

Carbon monoxide (CO) can be a tricky and dangerous source of indoor air pollution. It is a gas that is colorless and odorless, so it can be difficult to detect without a carbon monoxide alarm. The effects of CO on a person's health vary based on the levels of the gas inside a building. At low levels, it might make you feel tired. At higher levels, it can cause confusion, headaches and flu-like symptoms.

Potential sources of CO include:

  • Appliances: Gas stoves, charcoal grills, clothes dryers, water heaters, furnaces, space heaters and gas fireplaces
  • Smoke: Tobacco smoke from cigarettes and cigars, wood-burning fireplaces and charcoal grills
  • Power Tools: Chainsaws, gas lawnmowers, gas-powered tools

  • One way to keep CO levels inside of your home within the recommended levels is to have your heating system inspected regularly. It is also a good idea to install a carbon monoxide detector with an alarm so that you know if CO levels become elevated.


Formaldehyde is another type of colorless gas. It is produced as a result of combustion and is found in tobacco smoke as well as the emissions produced by fuel-burning heating systems.

Certain products found in buildings and homes can also contain formaldehyde. These products, such as furniture made from particleboard or compressed wood, can "off-gas" formaldehyde, especially in hot conditions. Ways to avoid or reduce exposure to formaldehyde include choosing furniture made from materials that comply with ANSI/HPVA HP-1-2009, ANSI A208.1-2009 or ANSI A208.2-2009 standards. If you are not sure of the materials used in your furniture, keeping your home well ventilated will allow formaldehyde to dissipate.

Environmental Tobacco Smoke

Smoking tobacco products inside a home or building reduces indoor air quality in a couple of ways. Tobacco smoke produces both CO and formaldehyde. It also contains approximately 7,000 other substances. The best way to limit exposure to the pollutants found in tobacco smoke, both for the person who smokes and others in the home, is to avoid smoking indoors.

Volatile Organic Compounds

A volatile organic compound (VOC) is a gas that is released into the air by a product. Formaldehyde is an example of a VOC. Levels of VOCs are often are 10 times higher in indoor environments compared to outdoor environments.

A wide range of products found in homes and other buildings can produce VOCs:

  • Paint
  • Cleaning products
  • Carpeting
  • Laminate flooring
  • Air fresheners
  • Pesticides
  • Glue
  • Dry cleaning solutions (found on dry cleaned clothing)
  • Permanent markers
  • Cosmetics

Looking for and using products that do not contain VOCs is one way to reduce exposure to them indoors. Opening the windows and improving ventilation indoors can also help to lower exposure.

What Are the Effects of Indoor Air Quality on Your Health?

Relaxed woman resting breathing fresh air at home on sofaPollutants that affect indoor air quality can also affect your health. In rare cases, poor indoor air quality can lead to specific diseases, such as Legionnaire’s disease. In other instances, you might have symptoms and feel ill effects because of poor air quality, but you might not be able to put your finger on a specific illness.

The effects of indoor air quality on your health can be immediate, meaning they develop right away after exposure to a particular pollutant. These effects can also be long-term, which means it can take years for symptoms to develop, or you need repeated exposure to the contaminant to notice any ill effects.

Some of the immediate health effects of poor indoor air quality include:
  • Headaches
  • Dizziness
  • Fatigue
  • Irritation to the eyes, throat or nose
  • Difficulty breathing (asthma symptoms)
  • Memory trouble
  • Stuffy or runny nose

One way to tell if your symptoms are due to poor indoor air quality or another cause, such as a cold, is to evaluate when they occur. If you only feel sneezy or notice that your nose only runs when you’re indoors, then it’s more likely that something is going on with the air in your home, rather than a cold or flu.

The long-term health effects of poor indoor air quality tend to be more serious than a runny nose or a headache. Ongoing exposure to pollutants in a home or building can potentially lead to heart or lung disease as well as certain types of cancer.

How Do You Know If Your Indoor Air Is Unhealthy?

There are a few ways to tell if the air inside your home is unhealthy. The first thing to do is to pay attention to any signs or symptoms that the indoor air quality is poor. If you notice dizziness, sneezing and other health effects when you are at home, and these symptoms seem to clear up when you leave, that can be a sign that your indoor air is unhealthy.

Another way to determine if the air in your home is unhealthy is to examine and evaluate what you and other members of your family do inside. If people smoke indoors, regularly spray pesticides or air fresheners, or frequently work on craft projects with paint, those activities can affect your home’s air quality.

Damp areas, condensation on the windows and visible mold growth are also signs that something is amiss. A musty or otherwise unpleasant odor in your home can suggest that humidity levels are too high. It is possible to measure the level of some gases and VOCs inside the home. For example, a carbon monoxide detector will alert you if CO levels creep up.

How Can You Improve Indoor Air Quality?

Improving the air quality in your home often involves three steps. The goal is to limit the pollutants indoors so that everyone who comes into your house can breathe more easily.

Keep Pollutants Out

The first step to improving indoor air quality is to limit the number of pollutants that get into your home. There are multiple ways you can restrict or control the source of pollution indoors.

  • Choose products that do not contain or release VOCs.
  • Reconsider having pets with fur or feathers, especially if members of your household are allergic.
  • Choose hardwood floors over carpeting, which can limit dust and dust mites.
  • Have the filters in your heating system replaced regularly.
  • Adjust or replace large appliances, such as a gas stove or furnace, to reduce the emissions they produce.
  • Keep humidity levels indoors within the recommended levels (30 to 50 percent).
  • Don't smoke or vape indoors.

Improve the Air Circulation in Your House

Although reducing the number of pollutants that make it into your home is the first line of defense when it comes to improving indoor air quality, it is not the only thing you can do. Improving your home's ventilation or air circulation also helps.

In the bathroom or kitchen, you can improve air circulation and lower humidity levels by running an exhaust fan. Running a fan in your bathroom while you shower will help to reduce mold growth. In the kitchen, an exhaust fan will help to direct any particulates out of the house.

The simplest way to improve the ventilation of your house is to open up the windows or doors on a beautiful day. Opening the windows on all sides of the house can create a gentle breeze or current, helping the air flow through your home.

Clean the Air Inside Your Home

The third thing you can do to improve the air quality indoors is to clean the air. Air cleaners work by filtering dust and other particles from the air, and they are meant to be a complement to other methods of improving indoor air quality, such as reducing the source of pollution and improving ventilation.

Along with installing an air purification system in your home, improving the ability of your heating system to filter the air can also help to improve indoor air quality. Installing a dehumidifier or otherwise controlling your home's humidity levels can also lead to an improvement in your home's indoor air quality.

Types of Indoor Air Quality

There are three basic types of Indoor Air Quality control. Each type can be taken care of with different types of IAQ products that can be easily added to your existing HVAC system. 


In the summer there is usually too much humidity in your home and in the winter there is not enough. This can cause many comfort issues and can even damage a home. We use humidifiers to add humidity in the winter, and we use dehumidifiers and air conditioners to remove humidity in the summer.


There can be particles of various sizes floating in the air inside of your home. Sometimes you can see them when the sunlight is shining through a window, and others are so small that you can’t see them at all. Air filters are used to remove airborne particles from the air. The better the air filter, the smaller the particle it can capture. Basic filters will only catch larger particles like dust but they will allow smaller particles to pass through. The primary function of a basic filter is to keep the A/C coil from becoming clogged with dust and lint. A more effective filter can capture tiny particles that can cause allergy issues like pollen and animal dander. Unfortunately, filters cannot capture microscopic items like bacteria, virus, mold spores and odors.


The final step in achieving healthy indoor air is to neutralize the microscopic contaminates and odors. There are two popular and proven means of doing this. The first option is a basic UV Light to sterilize germs, bacteria, mold and virus. The ultra-violet light works just like the sun by altering the DNA so that they cannot reproduce. In order for a virus or germ to make you sick, it has to be able to enter your body and then multiply. UV light alters its ability to multiply, so it becomes inert and cannot make you sick. The second option uses ionic technology. This cleans the air in a similar manner as how a lightning storm freshens the air outside. It generates positive and negative ions into the air, which cause tiny particles to become either positively or negatively charged. This works in two ways. First, it removes the hydrogen from the particles, which is their food source, basically causing them to starve. The second benefit is that it causes positive particles to cling to negative particles. This makes them larger as they clump together so that a filter can capture them or they become heavy enough to drop to the floor where they can be vacuumed up.

Products for Improving Indoor Air Quality

We offer several IAQ product options to help improve the quality of the air in your home. All of our products can easily be added to your existing heating and cooling system or in your home. To help you determine which product would best solve the air quality problems in your home, schedule a free in-home energy consultation with one of our expert energy consultants.

  • Electronic Air Cleaners from Aprilaire offer industry-leading particulate removal – providing you with protection against allergy and asthma triggers, a cleaner, healthier home with less dust, and superior protection of HVAC equipment.
  • Humidifiers eliminate the unhealthy and damaging effects of overly dry air on your family and home.
  • Dehumidifiers remove excess moisture from the air in your home, making your home more comfortable. Our Aprilaire dehumidifiers are quiet, feature a digital control, meet fresh air ventilation standards, and have a 5-year warranty.
  • PureAirTM Whole Home Solution systems provide cleaner air in every room and every breath. They system address three types of airborne pollutants: airborne particles, germs and bacteria, and chemical odors and vapors. They remove 99.9% of all particles like pollen, dust, and pet dander, as well as 90% of viruses like MRSA, cold, and flu.
  • UV Lights are an easy-to-install solution for having healthier air in your home. These lights are installed in your furnace or AC system and sterilize bacteria and virus particles as the air circulates through your system.

If you are concerned about the air quality inside your home in Southern Maryland, SMO Energy can help. We sell a variety of indoor air cleaning systems to help keep your home’s air as healthy for your family as possible. Call us at 888-222-3720 or get in touch with us online to find out what options we have available. We’ll help you select the best air purification system for your home.

We also offer service agreements that include an annual tune-up, which can help you ensure your heating system is not contributing to indoor pollution. Contact us today to schedule a consultation.

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