Your HVAC system is not immune to invasion by animal and insect pests. In general these systems don't offer an ideal habitat for most creatures, but you should always be on the lookout for signs. Be on alert for these signs of home pests.
If your annual inspection reveals that your ductwork is well sealed, and there are no cracks, gaps or holes, you probably don't have to worry about invasions in your ducts from critters that may have made their way into your attic or basement. However, it's not unknown for squirrels, rats or mice to chew through ductwork and try to set up housekeeping. You may be able to detect this through a smell that comes with your supply air; otherwise, you may need to have your ducts examined by technicians with special equipment and the right tools for cleaning them. Cockroaches might possibly invade ducts as well.
Your outdoor condenser could become a habitation for certain invaders in winter, particularly if you cover it up. Rodents and other critters may find it a nice, secure place to pass the cold spells. Rodents can chew wires, refrigerant lines and other parts and cause extensive damage.
Some snakes have been known to crawl into condensers when the unit is in use due to its warmth. However, it's likely they would be killed when the unit's fan starts up, which could damage it. Bees and wasps might also check out the condenser for a home.
INDOOR HVAC CABINET
Cockroaches, mice and other pests may try to invade your HVAC unit indoors, but this might be tied to a general infestation in your home. Most likely you will need to call a pest control company and have your home fumigated to get the invaders under control. If you need to have the ductwork and HVAC system treated for pests, you may have to move out of the home for a while, as the HVAC system could recirculate the pesticide.
Visit the Valley Heating, Cooling, Electrical and Solar website for more information on home pests and other HVAC tropics, or call (408) 868-5500.
Our goal is to help educate our customers in the South Bay Peninsula and Santa Cruz areas of California about energy and home comfort issues (specific to HVAC systems).