Cottonwood Season Is Coming For Your Condenser
Every late May or early Jun, the cottonwood trees along Denver's streets and creek corridors do their thing…and millions of fluffy white seeds drift into yards, pile against fences, and pack themselves into the fins of your outdoor AC condenser. Unlike dust or pollen, cottonwood fibers snag on aluminum fin edges and lock in. A few weeks of peak shedding can build a visible white mat across your unit's face, forcing the system to work harder, run longer, and run hotter than it's designed to. The good news is that the fix is something you can do it yourself. Of course, we are happy to help with this task if needed!
How to clean your condenser coil
Cut power at the disconnect box next to the unit.
Rinse with a garden hose from the inside out — spraying from outside pushes debris deeper. No pressure washers; the fins bend easily.
Let it dry 15–20 minutes, then restore power.
Check again in two weeks. In cottonwood-heavy areas, one cleaning won't last the season.
If your system still isn't cooling well after a coil cleaning, or if it's icing over, struggling at startup, or making new noises, that's worth a professional look. Restricted airflow over time can accelerate issues that were already developing quietly.
The dreaded Cottonwood fluff is coming either way. Your condenser doesn't have to be a casualty of it!