12 Steps to Promote Healthy Indoor Air Quality This Winter

Michael Rubino

December 5

When those outdoor temperatures drop to an uncomfortable level, the main thing on most of our minds is sticking inside and staying warm. But are these spaces promoting our ongoing wellness or are they creating unwanted exposure to contaminants like mold? It’s an important question! Taking action to promote healthy indoor air quality this winter can help ensure you’re breathing easy and enjoying that cozy, warm space. 

Unfortunately, far too many individuals suffer due to toxic indoor environments and poor indoor air quality. When the average person breathes 20,000 breaths per day and spends 90% of their time indoors, it’s easy to see how the air we breathe inside these spaces can impact our bodies. If it’s filled with contaminants like mold spores, bacteria, mycotoxins, and more, that will negatively impact our health. Every time we inhale in an indoor space, all of those particles enter our body and start causing mayhem.

That’s why it’s especially important to focus on taking steps to promote home health during the winter, when we’re spending more time indoors. Not to mention, our homes are pretty much on lockdown during those chilly months to maintain that warm indoor temperature. With homes pushing for net-zero energy efficiency, this means that any particles that make their way into our indoor spaces will remain there until they’re actively removed. 

If they’re not removed, they’ll continue to build up and increase the toxic load in the space.

To ensure your home is prepped for the cold months ahead, here are 12 steps to promote healthy indoor air quality this winter.

1. Investing in Air Purification

Indoor Air Quality in Winter

 Air purifiers are rockstars for helping reduce the number of particles floating around in the air. The fewer particles there are, the cleaner your indoor environment will be. 

Not all air purifiers are built the same, though. You want to go with a unit that removes the maximum number of contaminants possible and does it all of the time, not just some of the time. That way, they don’t recirculate back into the environment and potentially make their way into the bodies of those spending time inside. Air purifiers should at least meet HEPA status, meaning that they remove 99.97% of particles as small as 0.3 microns. If it can remove smaller particles, that’s even better. Some can also work to reduce other contaminants such as formaldehyde, VOCs, bacteria, viruses, and biotoxins. 

Also, pay attention to the space recommendations on the particular unit to ensure it’s equipped to filter the air for the size of the room. The space recommendation is why whole-house air purifiers are the best option because they’re installed at the home’s point of entry and help circulate filtered air throughout the entire building. As a bonus, they also add a layer of protection for the HVAC system as a whole. Particles such as mold spores can make their way into the system if they’re not properly filtered out and can grow within the unit.

Check out this blog post for more information on choosing the right air purifier. 

2. Changing HVAC Air Filters

One of the keys to healthier indoor air quality? Those HVAC filters!

As the lungs of the home, the HVAC system is the first line of defense in removing particles from your air. The air filters themselves are what allow the system to cleanse the air and recirculate the cleaner air back into your indoor environment. However, dirty air filters aren’t able to properly eliminate particles and can also cause issues with the HVAC system itself. Changing them on time will avoid these issues and help you breathe easier this winter.

As for timing, generally, the rule is to replace the filters every 90 days, but that’s not always the case. For those who have autoimmune conditions or allergies, the more often the filter is changed, the better to help promote as much clean air as possible.

Other factors, such as the home’s location, the age of the HVAC system, and the state of the air quality can also influence how often these need to be replaced. If you’re not sure whether to change the filter earlier, a few signs to look out for include discoloration of the filter, odd odors, higher electricity bills, a decrease in airflow, or dust around the vents or condenser coils. Chronic health issues can also point to poor indoor air quality.

Finally, the type of filter also plays a role in how frequently it should be replaced. Check with the manufacturer for suggestions on how often to replace the filter and signs to look out for that indicate it has reached the end of its lifecycle.

Bonus Tip: Speaking of HVAC filters, switch to the highest-rated MERV filters possible for the specific HVAC and replace them on time. The details on which can be used and when to replace them can be found in the manufacturer’s instructions. The key thing to keep in mind is that the smaller the particles these filters can eliminate, the better. Otherwise, they’ll just circulate straight back into the home. 

3. Regularly Cleaning (especially dusting)

Indoor Air Quality in Winter

During those cold winter months, opening up doors and windows isn’t exactly an option. And, thanks to modern building practices pushing for net-zero energy efficiency, there’s very little airflow between our indoor and outdoor environments. The result is that any particles making their way into your home will remain there until they’re actively removed. 

That’s why cleaning during the winter months is so important! The more we can clean, the lower the particle load will be in the home and the healthier the indoor air quality will be. Not to mention, it lessens the ability for microbial growth. The fewer spores there are in your home, the lower the chances that one will land on a surface and opportunistically begin to grow.

So, grab that HEPA vacuum cleaner, botanical cleaning products, and microfiber towels, and give your indoor environment a deep clean. Make sure to add dusting to your cleaning routine, though!

Microscopic particles settle where dust settles. So all those door frames, shelves, baseboards, furniture, and other surfaces are covered in dust? Chances are that other particles like mold spores, mycotoxins, and bacteria are hanging out as well. 

Regular dusting with microfiber towels can help to reduce the number of particles that can get kicked up into the air when the surface is disturbed. 

If you’re concerned about what exactly is in your dust and if it could indicate a problem in your home, consider investing in a tool such as The Dust Test. This revolutionary product can help identify what’s in a home so that you can have peace of mind that your indoor space is supporting your health or validate that your home is causing wellness problems. 

4. Check For Leaks

Mold can grow in as little as 24-48 hours if moisture and food sources are present. Leaks create the perfect opportunity for this to occur. Once that microbial growth is established, it will begin to lower your indoor air quality and can lead to a long list of adverse health reactions.

Checking for leaks is important for promoting home health because not all leaks are noticeable events. Oftentimes, a small leak will occur (like underneath a sink), and it’s not discovered until months or even years later. Any microbial growth present will have the chance to prosper and spread, creating a toxic hazard zone in your home.

Combing through your house for any issues is a great way to avoid this scenario! The sooner you can catch a problem, the better. Addressing any issues quickly and correctly can help prevent exposure and save money from costly remediation projects down the line. 

Places to check include: 

  • Underneath sinks
  • Attic
  • Around toilets and showers
  • Near appliances such as the dishwasher or laundry machine
  • Ceilings
  • Basement 
  • Hot water tank

Another great idea to determine if there’s a hidden leak is to assess your water usage and bill. If these are abnormally high, there could be an issue somewhere in your home. In that case, consider hiring an inspector to come in and assess the building.

5. Assessing for Structural Issues

cracks in foundation

Problems such as cracks in the foundation can allow moisture to intrude during rain and snow. Combined with the cold temperatures, this not only causes water damage but can also lead to increased cracking and other problems as the moisture enters the home and refreezes. Not only can this be dangerous for the integrity of the building, but it also creates the perfect opportunity for microbial growth.

Less moisture is key to maintaining a home with healthy air quality.

Ensuring the home's exterior is prepped to act as an appropriate barrier is a huge aspect of avoiding water intrusion. With that in mind, before the frigid months set in, take a close look around your home to determine if there are any cracks, gaps, damage, or other issues that could allow moisture inside. 

Places to check include:

  • Foundation 
  • Roof
  • Windowsills 
  • Door frames 
  • Siding

If you find any problems, take care of them ASAP. The sooner you can catch and resolve the problem, the better. 

6. Ensuring that Trees and Limbs Aren't a Threat

As winter approaches, so do the chances of snow and ice storms. This can lead to broken tree branches or, in some cases, the entire tree coming down. Either scenario can cause serious structural damage to a home if the tree is close enough to the building. This opens the door for serious water damage.

And, as we know, any water damage in a home is an opportunity for microbial growth to occur. Not to mention, it leads to more money coming out of your pocket to resolve the damage created by the fallen tree. 

To ensure this situation doesn’t occur, make sure that all trees are far enough away from the home that they won’t cause any structural damage after snow or ice. Generally, the rule is a minimum of 15 feet for medium trees, but the full length depends on the tree's mature height. It’s best to operate under the idea that it's better to be safe than sorry. 

As for limbs, make sure that no branches are hanging over the house before the cold weather sets in. 

7. Protect Pipes to Avoid Water Damage


As the temperature drops below freezing, pipes can ice over and burst, causing water damage indoors. As mentioned before, these moisture-related issues create a perfect opportunity for contaminants like mold to grow. Ensuring the pipes in your home are in tip-top shape is key to avoiding unwanted and expensive repercussions from a burst.

With that in mind, take a close look at the unheated areas of your home. Some of the most common places these are located are crawlspaces, basements, attics, and garages. Make sure that they’re properly insulated to avoid freezing over, If they’re not, address that problem ASAP. 

Contact the professionals if you’re not confident in your insulation abilities or have questions! 

8. Inspect the Chimney/Fireplace (if you haven’t already)

Sitting by the fire and drinking hot chocolate is a staple during the winter for a reason: it helps fight off those seriously cold temperatures!

But, before lighting a fire during those chilly winter nights, make sure to schedule a professional to come out and inspect the fixture. During the summer, the fireplace could have been blocked by debris or developed structural issues, leading to poor indoor air quality and possible water intrusion. 

The person coming in should ensure that:

  • The cap, crown, and flashing are in good condition and don’t have any damage that could allow moisture to enter
  • There’s no debris blocking the chute 
  • The flu is operating correctly, so that sooty air gets out 
  • The structural foundation of the chimney has no damage  
  • Any creosote, a harmful byproduct of burning wood, is removed

Collectively, this will ensure that your heat source is ready to rock and roll for the winter and promote healthier indoor air quality for you and your family. 

9. Clean the Gutters a Final Time

cleaning gutters

Clogged and faulty gutters are one of the top problems that lead to moisture intrusion into a home and, as a result, mold growth. This is particularly true in the wintertime because ice dams can form. Water can build up and collect throughout the gutter if the transportation system is clogged or damaged.  When this freezes, the melted snow can gradually trickle into areas such as beneath shingles. It can also cause damage to the gutters themselves, further exacerbating the issue.

Cleaning them thoroughly so they’re completely clear of debris, ensuring that they’re installed properly, and directing them away from the home's foundation help prevent water from intruding inside and causing mayhem during those chilly months.

10. Assess the Attic for Issues

Attics are at the top of the list for problematic areas during winter. As the cold air and snow outside come in contact with an attic with structural issues, it opens the door for problems like water damage.

To avoid this, head up to your attic and give it a thorough inspection before the super cold sets in.

Things to pay attention to include:

  • Making sure there’s proper ventilation: Without a steady airflow, humid air can get trapped inside the attic, creating the perfect conditions for mold growth. Checking for ventilation includes making sure that there are enough vents and that they’re not blocked by things like insulation. An easy trick is to check during the daytime—turn off all the lights and look for sunlight coming in through both the top and bottom vents. As for whether or not there are enough vents, check with your local building codes for mandatory requirements.
  • Ensuring the insulation is top-notch: If insulation is not installed correctly throughout the entire space, it can lead to improper airflow in the attic and trap moisture. Both situations can end up leading to microbial growth.
  • Inspect for microbial growth or water damage: Some of the top areas to check for problems include rafters, joists, fascia boards, roof valleys, skylights, chimneys, windows, flashings, attic plumbing stacks, air conditioners, and vapor barriers. Make sure to use your nose as well. Mold growth often creates a damp, musty, cigar-like smell due to the release of gases called microbial volatile organic compounds (MVOC).

Check out this blog post for more information on ensuring your attic is promoting home health. 

11. Maintain Humidity Between 35-50%


This level is the sweet spot for promoting home health.

Some species of mold can begin to grow in areas with high humidity. This moisture-rich air can cause condensation as it hits warm surfaces, creating yet another opportunity for microbial growth. Remember, all it takes is 24-48 hours on a surface with food and moisture for a spore to transition into an active colony. 

On the other hand, levels that are too low can cause structural issues in a home, particularly with wooden surfaces. Hence, it’s important to maintain that perfect sweet spot.

A great idea is to invest in a hygrometer and continually monitor your indoor humidity levels. If it goes too far in either direction, you can then jump into action to fix it and ensure your environment remains a safe space. 

If they widely fluctuate and you have no idea why, there may be a larger problem at home, such as structural issues. In this case, contact an expert to get their input on the issue so it can be resolved ASAP.

12. Deep Cleaning Window AC Units 

For those in warmer climates, now that the AC has officially been turned off for the year (because there are always those random warm days in the fall), it’s a great time to ensure any window AC units are deep cleaned and ready to rock and roll for the next warm season. Without proper care, these bringers of chilly air can become contaminated with microbial growth (like mold), pushing your indoor environment into a toxic zone. 

Why is there mold?

Like any item in a home, dust and other organic matter settle inside the machine, offering plenty of edible options for a lucky mold spore. As for moisture, this can occur due to various situations. 

A few include: 

  • Condensation forming as the cool air hits the warmer air in the home when the unit is turned on
  • High humidity can lead to condensation on the coils or interior of the machine 

Giving the unit a deep clean before it’s retired for the months of cold weather coming up will ensure that there’s not a contamination problem and remove the opportunity for one to develop while it’s not turned on. After all, the best way to handle a mold problem is to prevent it from occurring in the first place.

Check out this blog post for a full list of steps to take to clean one of these units.

Remaining Safe and Warm

Indoor Air Quality in Winter

Creating a healthy home environment is a continual process, like any other home maintenance task. It may seem like a lot of work at first glance, but you can never be too over the top when it comes to your wellness. We focus on eating healthy, drinking water, and exercising frequently, but what about taking care of the air we breathe?

With how much time we spend indoors during this chilly season, this factor is key to promoting our ongoing well-being! No one wants to hang out at home watching their favorite TV show and breathe in all sorts of toxic contaminants. That’s just a recipe for disaster.

Tackling all of the steps above before the cold weather sets in can help ensure you’re well on your way to a healthy home environment that supports you and your family!