5050 Quorum Dr Suite 700, Dallas, TX 75254 Open 24 Hours
Schedule a Repair
972-423-0012

Fall Allergy Season and Your HVAC System in Dallas

Written by the technicians at Dallas Heating and Air Conditioning, serving Dallas, TX and the DFW metroplex since 2020.

Dallas's worst allergy stretch isn't spring — it's September and October, driven by ragweed pollen and mold spores that peak as the weather cools. Your HVAC system is either helping or hurting: a clogged or low-grade filter lets allergens recirculate through your home, while a filter change and a few settings adjustments meaningfully cut what makes it into your indoor air. Switch to a MERV 11–13 filter for the season, keep the system running (not just the fan), and change filters monthly through October.

Why Fall Is Actually Worse Than Spring in Dallas

Most people brace for spring allergies and let their guard down by September. That’s backwards for North Texas. Ragweed pollen peaks here from late August through October, and it’s joined by outdoor mold spores that spike as falling leaves decompose. Add in the fact that Dallas homes are typically sealed up tighter once the first cool fronts arrive — less fresh-air exchange, more recirculated indoor air — and September–October becomes the toughest stretch for a lot of allergy sufferers.

Your Filter Is Doing More Work Than You Think

Every time your system runs, it pulls return air through the filter before circulating it back through the house. A basic fiberglass filter (MERV 1–4) is designed to protect the equipment, not your lungs — it does very little against pollen and mold spores. Stepping up to a MERV 11–13 filter for allergy season captures a meaningfully higher share of those particles, without the airflow restriction of hospital-grade filters that aren’t designed for residential blowers.

What to Check This Month

  • Filter grade. If you’re running a basic MERV 4 or lower, step up to MERV 11–13 for September and October, then reassess.
  • Filter age. Change monthly during allergy season — a filter that’s doing its job catching more particles also clogs faster.
  • Thermostat fan setting. Set the fan to AUTO, not ON. A fan that runs continuously without the compressor cycling can actually re-suspend settled dust and pollen rather than filtering it out.
  • Return vents. Make sure furniture or rugs aren’t blocking return vents — restricted returns force the system to work harder and can pull air from unconditioned spaces like attics through gaps instead of through the filter.

When It’s More Than a Filter Problem

If allergy symptoms are severe indoors even with a good filter and regular changes, the next place to look is duct leakage — gaps in ductwork, especially in an attic, can pull in unfiltered outdoor air and dust directly into your supply air. That’s a job for an inspection, not a filter swap. A fall maintenance visit checks airflow and can flag duct issues before winter.

The Filter Grade Trade-Off

Higher MERV filters restrict airflow more than basic filters, and some older or lower-capacity systems aren’t designed for MERV 13 and above without a static pressure check. If you have an older system, ask your technician to confirm your system can handle a MERV 11–13 filter before switching — the wrong filter for your equipment can strain the blower motor over time.

Comprehensive HVAC Brand Expertise: Quality and Trust You Can Rely On

Throughout the years, our local HVAC repair company has amassed a wealth of experience working with a wide range of brands and their unique systems. Our highly trained technicians have hands-on expertise with several brands, such as Amana, Bryant, Carrier, Daikin, and Goodman. This extensive experience has equipped our team with the ability to master various repair techniques and maintenance practices, ensuring they can handle any issue, regardless of your system's make or model.

HVAC brands we service, including Amana, American Standard, Carrier, Bryant, Goodman, Trane, Ruud, Lennox, and Rheem

Selecting a dependable company like Dallas Heating and Air Conditioning is key to preserving your HVAC system's functionality and extending its life. Our team's extensive knowledge of various brands enables us to handle any challenge that may surface. Additionally, our focus on maintaining high levels of professionalism and customer care showcases our trustworthiness, delivering reliable, best-in-class solutions that give you confidence in our services.

FAQs

Frequently Asked Questions

Why are my allergies worse in fall than spring in Dallas?

Ragweed pollen and mold spores both peak in North Texas from late August through October, combined with homes sealing up tighter as the weather cools — which means less fresh air and more recirculated indoor allergens.

What MERV filter should I use for allergy season?

MERV 11–13 meaningfully improves allergen capture over a basic MERV 1–4 filter without the airflow restriction of hospital-grade filters. Confirm your system can handle it if you have an older unit.

Should I run my HVAC fan constantly during allergy season?

No — set the fan to AUTO, not ON. Continuous fan operation without the compressor running can re-suspend settled dust and pollen instead of filtering it out.

Can duct leaks make allergies worse?

Yes. Leaky ductwork, especially in an attic, can pull unfiltered outdoor air and dust directly into your supply air, bypassing the filter entirely. A fall maintenance visit can check for this.

24/7 Emergency Service

Need Fast And Reliable HVAC Service Today?

972-423-0012

Open 24 Hours

972-423-0012