Critters in the Vents: Dealing with Animals in HVAC Systems

HWCS Expert Team

Your home’s HVAC system is designed to circulate clean air. When animals break in, it circulates odors, dander, and pathogens instead. The metal ductwork of a home acts like a super-highway for rodents, allowing them to travel to every room in the house unseen.

How They Get In

  • Disconnected Ducts: In crawlspaces, flex-ducts often fall off the main trunk line, leaving a wide-open hole for raccoons or opossums to climb in.
  • Chewing: Mice can chew through flexible foil ducts in minutes.
  • Floor Vents: Sometimes, a mouse falls through a floor register and gets trapped in the boot.

The Signs

  1. The Urine Smell: When the furnace turns on, do you smell a sharp, acrid odor? The heat vaporizes the urine left in the ducts, blowing it into every room.
  2. Magnoified Sound: Metal carries sound well. A tiny mouse walking in a duct can sound like a monster scratching due to the acoustics.

The Solution

Getting animals out of ductwork is tricky.

  1. Extraction: We cannot use poison (the animal will die in the duct and smell forever). We must use traps placed at strategic points in the system.
  2. Repair: We repair the breached ductwork, replacing soft flex-duct with rigid metal where possible to prevent chewing.
  3. Sanitization: This is crucial. If the ducts are filled with droppings, the air quality in your home is compromised. We can clean and sanitize the accessible ducts or recommend a full duct cleaning service.
  4. Vent Guards: We install exterior covers on air intakes and exhaust vents to stop future entry.

Protect your lungs and your furnace. If your vents smell like a zoo, call HWCS.