Delivering home comfort from our family to yours since 1967
Inquiries and Emergency Services
REQUEST A FREE QUOTE
REQUEST A SERVICE
Appleby Systems Logo
Inquiries and Emergency Services

Why Indoor Air Quality Gets Worse in Spring and What You Can Do About It

Posted on April 23, 2025
by Appleby Systems
Why Indoor Air Quality Gets Worse in Spring

Spring is a welcome change after a long winter, but it also marks a time when indoor air quality (IAQ) tends to deteriorate in many homes. Between lingering winter pollutants and fresh spring allergens, your home’s air can become a silent health risk just as you’re opening windows and stepping into warmer weather. 

Let’s break down why spring impacts your indoor air, what makes it worse, and how you can take control for a cleaner, healthier living space. 

1. Spring Allergens Flood In and Stay Trapped Inside 

As trees, grass, and flowers bloom, they release pollen and mould spores into the air. Opening windows and doors can bring those allergens into your home, where they often linger. 

Worse still, spring tends to be wet, encouraging mould growth inside basements, ducts, and poorly ventilated areas. Unless your air is filtered properly, these irritants accumulate, triggering allergies and respiratory issues. 

2. Your House Is Still in “Winter Mode” 

Most Canadian homes are tightly sealed throughout the winter to retain heat. As spring begins, that sealed environment remains unless actively adjusted—meaning stale air, dust buildup, and lingering volatile organic compounds (VOCs) from household materials continue to circulate. 

If you haven’t refreshed your ventilation system, it’s essentially recycling the same air from the heating season, i.e. air that contains dust, pet dander, smoke particles, and potentially harmful chemicals. 

3. Rising Humidity Feeds Mold and Dust Mites 

Spring brings increased humidity, especially with early rains and warming temperatures. High indoor humidity creates ideal conditions for mould, mildew, and dust mites—three major contributors to poor air quality and allergy symptoms. 

Balanced humidity (ideally between 35–50%) is crucial to maintain comfort and prevent microbial growth in ductwork, crawlspaces, and poorly insulated corners of your home. 

4. Your HVAC System Might Be Spreading Pollutants 

If you haven’t had your HVAC system serviced since last fall, spring is the perfect time. Dirty air filters, neglected ductwork, and underperforming ventilators can all contribute to poor indoor air circulation and contaminant buildup. 

Your heating and cooling system should help clean the air rather than spread allergens or circulate dust. 

How to Improve Your Indoor Air Quality This Spring 

Spring is the ideal time for a home air quality reset. Here’s how to do it: 

  • Replace your furnace and HVAC filters. Use high-efficiency pleated filters that capture pollen, mould spores, and fine dust. 
  • Schedule duct cleaning. If it’s been a few years, your ductwork may be contributing to air pollution. 
  • Use a heat recovery ventilator (HRV). These units exchange stale indoor air with fresh, filtered outdoor air—without sacrificing energy efficiency. 
  • Control indoor humidity. Use a dehumidifier if your indoor levels rise above 50%. 

These small upgrades can dramatically improve your home’s air quality throughout the entire season. 

Don’t Let Spring Allergies Start at Home 

The air inside your home should be a refuge from outdoor allergens, not a source of them. Whether you suffer from seasonal allergies, have young children, or simply want to breathe easier, investing in better IAQ is one of the smartest spring home improvements you can make. 

Ready to breathe cleaner air this spring? Contact Appleby Systems to schedule a home air quality assessment or explore our full range of IAQ solutions. 

Appleby Systems Arrows
Serving Halton region Burlington & Oakville, Mississauga, Hamilton, Ancaster & Dundas since 1967
©2025 Appleby Systems. All Rights Reserved. | Privacy Policy | Sitemap
Web Design and SEO in the Greater Toronto and Hamilton Area by WEB ROI
tagsmartphonecrossmenu
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram