I know what you are thinking, what do these animals have to do with my heating & air conditioning ? Well, actually a lot. All of these animals can do significant and costly damage to your heating & air conditioning equipment including the duct system and wiring/electrical system.

The 1^st culprit on the list is your innocent family dog (or your friendly neighborhood roaming dogs). Dog urine is extremely damaging to your outdoor condenser coil. They will usually go over and over on the same spot on the coil causing corrosion of the aluminum fins on the condenser coil and eventually causing the copper tubing to fail and start leaking refrigerant. If your outdoor unit is showing signs like the image on the right then you have a dog problem that will at some point become a cooling failure and a costly repair. Putting a small fence around the unit should keep this from happening keeping in mind the unit does need room to breath. A wire type fence should not be a problem. If you use a solid fence you need at least 1 foot around the unit to breath keeping in mind room is needed to get in and service and clean the unit.

The other 2 culprits on the list (Raccoons & squirrels) can do similar damage to your heating & cooling systems. Both like to chew. Raccons are more likely to do major damage to your duct system if it is located in your attic or crawl space. The image shows just some of the damage raccoons can do especially to insulated flex duct that is widely used in our industry. Raccoons love the insulation used on flex duct and also the insulation we use to wrap metal duct for the same reason we use it. They make beds and nests out of it to keep them and their babies warm. Squirrels are less likely to do major damage to your duct work than raccoons simply because they are smaller but they also like the insulation. Their insulation of choice seems to be the insulation we use to insulate our water or refrigerant piping. They chew the insulation off of the piping which will lower the efficiency of your air conditioner if the exposed piping is in a hot attic and it may also cause condensation on the piping creating a ceiling leak and damage to your drywall ceilings. Both raccoons and squirrels like to also chew on your wiring. They really like to chew on the low voltage control wiring. Most of today’s equipment contains circuit boards much like in your computer. Most of these boards are not inexpensive. The chewing of the wires could cause a low voltage short and could damage one or more of these circuit boards creating the need for a costly repair. They can also chew into the high voltage wiring which could create a fire hazard issue or they could be electrocuted and then cause a bad odor issue when they start to decompose.  Another negative of having raccoons and squirrels in your attic or crawl space is the odor from the droppings that can be transferred into the living space through the duct work. Just look around your your home at roof vents, gable vents, soffits and soffit vents for any damage or holes that may let them into your attic. Also check any accesses into your crawl space or any crawl space vents to make sure you are sealed up properly. Like the old saying goes “An ounce of prevention is worth a pound of cure” A little patch or repair now may save you a costly repair later.