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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.
All interactions from sales to installation were Courteous and professional. The installation was seamless and the attention to detail including clean up was outstanding. I highly recommend TwinTech Heating and Cooling.
Twintech's Salesman Dave arrived promptly was friendly and courteous, listened and assured us the installation would be completed according to our requests. The crew arrived early morning on May 11th, 2018 and worked through till late afternoon non-stop. They were very friendly, very professional, their expertise was excellent, their workmanship outstanding and the installation was completed in a timely and efficient manner. We were completely satisfied and happy with the quality of the work.
I had cold and hot spots all over my 70 yr old home. My furnace is quite new and Greg optimized the fan and furnace. The original installer just took it out of the box with factory settings and installed it- basically running at 50% of capacity. Greg also routed heat into my laundry room, yeah - so now I can renovate laundry room - thanks Greg. He is honest, professional and knowledgeable. I will be calling him back in the spring to optimize my AC as well.
Wonderful from beginning to end. I tend to fret and worry about home improvements but the excellent team at TwinTech put my mind as ease. They listen, they are patient and best of all ... the work they did is amazing! I chose the Goodman 80K BTU 2 stage furnace and the matching Goodman air conditioner. Greg, Grant and Poitr "Peter" arrived on time, took great care, explained everything to me and they answered all of my questions. They carefully adjusted the factory settings to optimize the furnace for my house and they also checked the duct work in the basement. Dave, the Sales Manager, came by to say "hello" and to see if I was happy. YES, I am happy with the work! The furnace is very quiet. I have it running on low just to circulate the air in the house and it's so much quieter than my old furnace. When I need new duct work for an upcoming basement renovation TwinTech will be my first choice. I highly recommend TwinTech. PS. They were even nice to my dogs.
Greg was prompt on the scheduled day of installation and the work was done well within the time estimated beforehand. Installation was neat and the equipment and scope of work was as specified in the quote. One item I must point out is that we were faced with a "No Heat" situation the day before the scheduled installation and Greg came out to address it free of charge. Not only that, but he also corrected an installation fault with our smart thermostat that was not part of the original job, again free of charge.
Greg came by to do a routine furnace checkup. He was very knowledgeable and professional, letting me know what's being checked/adjusted and giving me tips to ensure everything runs smooth. Very honest and upfront about what's working fine vs. what may need to be fixed/replaced. He didn't attempt to up sell anything that wasn't necessary. I'm glad to have finally found someone I can trust and rely on for all my HVAC needs - furnace, A/C, and hot water tank.
I'm very happy with the work that was done. Everyone from salesperson to the installers were friendly and professional. They were on time and cleaned up the job site after it was installed. They also answered all my follow up questions promptly. I wouldn't hesitate to work with them or recommend them again.
Thanks to the team at Twin Tech for a great job installing my new heat pump/ac unit. The guys were very polite and professional. When they left you would never have known they had been there except for the new Mitsubishi unit on the wall!! would highly recommend the Twin Tech team.
Installed professionally, no delays, no rework needed. Very reliable contractor and sales person. Also installed BBQ gas line and some duct work.
Greg and Grant are friendly, reliable, and knowledgeable HVAC professionals. The twins, Dave and the entire team provided efficient top quality service. Our family plns to use Twintech for all of our future HVAC needs.
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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!
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