Is Indoor Air Quality Worse In Winter?

The U.S. EPA warns that poor indoor air quality is among the top health risks in American homes. Indoor air often has a significantly higher concentration of pollutants. The average American also spends as much as 90% of their time indoors. Let's explore why these concerns can be even bigger problems during the colder months.

Ambient Air Pollution Can Be Worse in Winter

The air inside your home can't be less polluted than the ambient air without some form of air purification. In many areas, it's common for ambient air pollution to be worse in winter. There are several reasons for this. Many homes and businesses are running fuel-burning heating systems that release particles into the air. There's often more vehicular traffic and less foot and bicycle traffic. Another factor is thermal inversion. This is where the upper layer of air acts like a lid that keeps air pollution trapped near the ground. Air is also denser and moves more slowly during the winter, which means that pollution doesn't disperse as well.

There's Less Ventilation

In the winter, people seal their homes to keep the warm air in. Modern homes have tighter building envelopes that improve energy efficiency but eliminate most natural ventilation. Also, many homes rely almost exclusively on passive ventilation. Often, the only mechanical ventilation a home gets is when the heat has cycled on. This is why the EPA warns that indoor pollution is often two to five times more concentrated than outdoor pollution. An effective solution to this problem is a mechanical ventilation system, such as whole-house fans. There are even fans designed specifically for the winter, such as heat recovery ventilators.

Heating Systems Cycle Frequently

During the winter, heating systems will often cycle on two to three times an hour and for 10 to 15 minutes each time. A well-maintained furnace or heat pump won't negatively impact IAQ, but it can exacerbate issues, such as excessive dust accumulation. A neglected heating system can negatively impact your IAQ. That's one reason you should schedule a heating tune-up in the fall before you need to run your heat. You should also check your HVAC filter at least once a month and swap it out as needed.

The Air Is Often Dry

Relative humidity is an oft-overlooked aspect of IAQ. The problem in winter is that the air is naturally drier. Running a furnace can also exacerbate that issue. A furnace heats the incoming dry air quickly. That air can now absorb substantial moisture and does so from the people, pets, and objects in your home. The EPA warns against an RH lower than 30 in the home. Many people prefer 40 RH for comfort and better sleep. If the RH is too low, it can irritate your respiratory system and even lead to inflammation. That can trigger allergies and asthma, worsen symptoms, and make you more prone to illness.

People Spend More Time Indoors

Another issue with many homes during winter is that there are more people on average in the home at once. Those people tend to be there while active for longer periods. Improving the ventilation will help to reduce the concentration of pollutants. A furnace humidifier or whole-house humidifier will help to enhance RH in the home. Homeowners should also consider an in-duct purifier and germicidal light. The air purifier can trap particles and absorb odors, gases, and chemicals. The germicidal light will neutralize bacteria, viruses, and other pathogens.

Households Often Inadvertently Introduce Pollutants

Families are more active in their homes during winter and can inadvertently introduce pollutants. Take care not to overwater houseplants. Store solvents and other chemicals outside the home. If painting or using chemicals for hobbies, make sure there's adequate ventilation. Also, take advantage of ceiling fans in all rooms where you have them.

IAQ Solutions in Virginia

New River Heating & Air has served Radford, VA and the entire New River Valley for over 30 years. Our company provides both residential and commercial services, including new construction. Our NATE-certified technicians install, maintain, and repair boilers, furnaces, heat pumps, air conditioners, and ductless mini-splits. We offer an annual membership plan that will save you money on maintenance and repairs. Our team is available 24/7 for emergencies.

We perform IAQ testing and offer solutions, including mechanical ventilation, air purification, germicidal lamps, dehumidifiers, and humidifiers. Our technicians clean ducts. We also install and service standby generators and tank and tankless water heaters. Call today with any questions or to schedule a service appointment or in-person consultation.