iaq
Maryland Spring Allergy Season: What Duct Cleaning Can (and Can't) Do
Maryland tree pollen peaks March-April. Here's what your HVAC does with it — and what we can actually measure.
By Yaniv Asayag · May 1, 2026
If you live in Maryland and you sneeze every spring, you're not imagining it: tree pollen season here typically peaks in March and April.
What HVAC actually does to indoor pollen
When your HVAC blower runs, it pulls air from inside the house, draws it through the return ducts, pushes it across the filter, and redistributes it through the supply ducts. If anything's stuck inside those ducts — pollen tracked in on clothes and pets, settled allergens from last spring, dust mite debris — some of it can be stirred up when the blower runs.
Be wary of anyone who promises a specific allergy result. The EPA's published guidance is that duct cleaning has never been shown to actually prevent health problems, and it suggests considering a cleaning when there's a specific reason — such as ducts clogged with dust and debris that is actually released from your supply registers. That's the standard we use when we tell you whether your system needs a cleaning at all.
The MERV 13 filter pairing
A better filter matters too. We suggest MERV 13 (the pleated, mid-tier type) if your system is rated for it — ask your HVAC contractor.
When to schedule
- Severe pollen allergy → mid-February (3-4 weeks before peak)
- Mild seasonal allergy → mid-March
- Pet + pollen allergies stacking → split year: Feb + August
- Just want it done before pollen season → any time before mid-April
The IAQ Lab Report angle
Eagle's 3rd-party IAQ Lab Report tests for pollen specifically. If pollen counts in your house aren't measurably lower after a cleaning, we re-clean at no charge.
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