[BACK]
Winter Allergies and Your HVAC System

When people think of allergies, spring pollen usually comes to mind.
But for many homeowners, allergy symptoms actually get worse during winter.
If you’re sneezing, coughing, or dealing with dry, irritated sinuses when the heat is on, your HVAC system may be playing a role.
Understanding how winter allergies work—and how your heating system affects indoor air quality—can help you breathe easier all season long.
Why Allergies Can Be Worse in Winter
During winter, homes are sealed tightly to keep cold air out.
While this improves energy efficiency, it also traps allergens indoors.
Unlike seasonal outdoor allergens, winter allergies are usually caused by indoor irritants.
Common winter allergy triggers include:
Dust and dust mites
Pet dander
Mold spores
Dry air irritation
Indoor air pollutants
Because your HVAC system constantly circulates air, it can either reduce these allergens—or spread them throughout your home.
How Your HVAC System Affects Winter Allergies
Your heating system is responsible for moving air through your home.
If it isn’t properly maintained, it can worsen allergy symptoms instead of improving comfort.
Air Circulation and Allergen Spread
Forced-air heating systems circulate air through ductwork and vents.
When dust, dander, or mold builds up inside the system, those particles get redistributed every time the heat runs.
Dirty Filters and Poor Filtration
Clogged or low-quality air filters allow allergens to pass through easily.
Over time, this leads to higher concentrations of airborne particles and increased allergy symptoms.
Dry Indoor Air
Heating systems reduce indoor humidity, which can:
Dry out nasal passages and sinuses
Make allergy symptoms feel more severe
Increase irritation of the throat and eyes
Dry air doesn’t cause allergies, but it can make existing symptoms much worse.
The Role of HVAC Filters in Allergy Control
Your HVAC filter is one of the most important tools for managing winter allergies.
High-quality filters can:
Trap dust, pollen, and pet dander
Reduce airborne allergen levels
Improve overall indoor air quality
For allergy-prone households, filters with higher MERV ratings are often recommended.
However, these filters must be changed regularly to prevent airflow restriction and system strain.
Most homes should replace filters every 1 to 3 months during winter, depending on usage and indoor conditions.
Ductwork and Hidden Allergens
Even with a good filter, allergens can accumulate in ductwork over time.
Duct-related allergy problems may come from:
Dust buildup
Mold growth caused by moisture
Air leaks pulling contaminants from attics or crawl spaces
Old or damaged insulation inside ducts
Sealing and cleaning ductwork can significantly reduce the amount of allergens circulating through your home.
Mold Growth and Heating Systems
Mold is a major indoor allergen and can be especially problematic in winter.
Condensation, humid basements, or neglected HVAC components can create the perfect environment for mold growth.
Signs mold may be affecting your air quality include:
Musty or earthy odors when heat runs
Persistent allergy symptoms indoors
Visible mold near vents or HVAC equipment
Professional HVAC inspections can identify moisture issues and prevent mold from spreading through your system.
How to Reduce Winter Allergies With Your HVAC System
If winter allergies are affecting your comfort, your HVAC system can be part of the solution.
Steps homeowners can take:
Replace air filters regularly
Schedule annual heating system maintenance
Keep vents and returns clean and unobstructed
Use a whole-home humidifier to balance moisture
Seal duct leaks to prevent contaminant entry
Consider air purification or UV systems
These improvements help create cleaner air while improving heating performance and efficiency.
When to Call an HVAC Professional
If allergy symptoms persist despite basic maintenance, it’s time to bring in a professional.
You should schedule an HVAC inspection if you notice:
Excessive dust buildup
Uneven heating or weak airflow
Strange odors when the system runs
Worsening allergy symptoms indoors
An HVAC professional can identify airflow issues, filtration problems, or hidden contaminants affecting your indoor air quality.
Final Thoughts
Winter allergies are often an indoor air quality issue—and your HVAC system plays a major role.
With proper filtration, humidity control, and regular maintenance, your heating system can help reduce allergens instead of spreading them.
At Twintech Heating & Cooling, we help homeowners improve comfort and air quality during the winter months.
If you’re struggling with allergies while running your heating system, professional HVAC solutions can make a noticeable difference in how you feel at home.
Once again Twin Tech came through and fixed my furnace. A young man by the name of Mitch came by tonight and he was so nice explained everything he was quick he was clean he turned off the lights even when he left the furnace room its just above and beyond Twin Tech always delivers and I just found out about them last year and I will use no one else but thanks again Mitch you are fantastic
I had a problem with the Furnace (Armstrong ultra V) and Greg diagnosed it on the phone. Even told me what the issue was and I was able to fix it. This level of service from a Business that is almost unknown today.
If you require service, reach out to Greg. I will definitely use them in the future!
We have been shopping for a heat pump for our home. We had 3 reps come in and make recommendations and provide a quote. Of the 3, Bob was so clearly so much more qualified, thorough and informed than the other two that the decision was a no brainer. As soon as we get our audit results Twintech will be installing our heat pump.
knowledgeable sales person, did not try to up-sell unneeded features,
and was easily contacted to ensure customer satisfaction.
Installation was expertly done by friendly guys, everything explained for use of the products. Old products were removed and returned to rental company as part of the service. Follow up call was received to check all was well. This is my second time using this company as I was fully satisfied with my previous air conditioning unit installation
Twintech recently installed a new furnace for me. Bob did a great job assessing what I had and needed. All details well explained including the importance of proper sizing of furnace and the value of multi stage heating and the variable speed blower. As a nurse, indoor air quality is a high priority so the variable speed motor running continuous is so good. 24/7 air cleaning. Greg did a great job on install, attention to detail so appreciated. Already notice such an improved comfort and heat. Thank you Twintech! You come as advertised. I will recommend to anyone in need of heating or cooling!
We received various quotes from 4 different companies and right away, the prompt and thorough communication from Bob from TwinTech stood out. He introduced himself, sent sample sites and information, and always confirmed any agreed to dates and times.
Bob was friendly and extremely knowledgeable about the topic of HVAC and it was clear he was passionate about his profession. He approached the job as if he was installing in his own home.
Prior to the new furnace & A/C installation, our old units were loud and inefficient - having several rooms feeling too cold in the winter and too hot in the summer. After installing the recommended units, all rooms stay at a consistent temperature- even the finished basement.
I highly recommend the TwinTech team - just an outstanding job at a reasonable price point.
The experience with Twintech was great from the start. Bob the sales manager was friendly and professional and did not use any pressure tactics. He was very knowledgeable.
The installation was completed by the twin owners in about 6-7 hours. Clean quiet easy going didn't mind when I poked my head in to see progress. Highly recommend
Just choose Twintech!
I do not usually write reviews and should have done this a few days sooner. But I was and still am enjoying the increased comfort in my home from the new furnace installed by Twintech.
From my initial call and conversation with Bob, I already had a good feeling that I would like this company.
I was provided information, pictures of great quality work previously completed.
When Bob came for the inspection of the furnace he was amazing. He gave so much great advice and told me all the areas that his team would resolve. I was very impressed as some of what he had suggested I had only seen in Youtube videos. The honesty and options for payment made this a no brainer. I decided I would like Twintech to replace my furnace.
The work was scheduled promptly week and took place within half a day. Gregg came to install the new furnace. Again amazing they carried out all the work promised. What was left was the best I have seen and speaks to how they take pride in the work they do and deliver. Gregg was really polite and professional and the furnace in my basement is a work of art.
They were friendly, fast, clean, & answered any questions I had. They are also offering an interest free 12 month payment plan - that really helped me out since this was an unexpected expense.
I had Twintech heating install a new furnace and ac unit. Bob, the sales rep, the installation team of Greg and Mitch were a 10 across the board. They were never pushy, gave me time to think about it. Once we decided , they were there in 24hrs. Great company to deal with. And they were nearly 5k less than a competitors quote for a top of the line furnace/ac unit verse mid level.
I highly recommend Twintech heating to anyone interested in anything HVAC.
Related Links:
oshawa gas furnace problems, ac service call, pickering hvac prices, local ac services, ajax furnace inspection, ac repair services, whitby furnace replacement, furnace repairs pickering, oshawa hvac furnaces, central ac service, ac unit maintenance, pickering gas furnace problems, ac installation near me, ajax hvac repair, hvac repairs, ac contractors, ac repair and service, whitby furnaces, residential furnace, residential ac repair, pickering hvac furnace, pickering furnace service, pickering furnaces, oshawa furnace inspection, oshawa furnaces, nearby ac repair,
We are very happy to recommend this company to everyone. Our furnace broke down on Sunday morning. We phoned them and before noon Grant the owner showed up. He worked on the furnace for about a hour not wanting to give up to fix the problem. The furnace was 17 years old. I was the one talking about replacing it. End result was the next day it was all done. On the Sunday Bob came over with heaters to warm up the house. We decided to replace the water heater at the same time. Thanks Grant for the excellent work. Thumbs up.
Right on time. Explained how to work the HRV in a different way so the house would not be so dry. Changed my whole house water filter for me as well. Friendly, helpful, caring service!
Very pleased with the professional service that TwinTech Heating and Cooling provided in replacing my furnace. I got several quotes from different service providers. Their price was excellent and they explained the features very well. We are very glad we went with TwinTech and highly recommend their services.
We were new homeowners in need of a second opinion. TwinTech Heating & Cooling were Amazing and professional. Very knowledgeable and great service all around. Recommend to anyone looking for honest and reliable services. Treated with respect and care. Thank you Greg, Mitch and Bob!
TwinTech is an excellent and honest company! I called them for a second opinion after being told by another company that I needed to replace my furnace. Turns out this was not the case at all! I did not need a new furnace. TwinTech did not push to make an unnecessary sale and saved me from a huge expense. Bob and Mitch were extremely professional and above all honest! I definitely recommend TwinTech!
An oversized furnace can lead to several issues, such as increased energy costs, uneven heating, and shorter equipment lifespan. To determine if your furnace unit is oversized, consider the following signs: 1. Short Cycling If your furnace f
Read MoreIf you are like most homeowners, there is a huge chance you’ve overlooked your HVAC system. Your HVAC system is crucial in maintaining the comfort level inside your home. Whether it is the cold months or the long summer nights, you cannot afford to
Read MoreNoticing the early signs that your furnace might need repair can prevent more severe issues down the line. Here are some key indicators that it's time to call a professional for furnace repair: 1. Strange Noises Banging, clanking, or squ
Read MoreYou might have certain furnace maintenance questions, especially since the heating season has just passed us. Remember, maintenance is key if you want your furnace to operate efficiently and reliably. It is never too early to prepare for the colder m
Read More