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Bugs Coming in Through Air Conditioner 

Bugs Coming in Through Air Conditioner 
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    As temperatures soar to new record highs in many places this summer, more individuals are relying on their air conditioners to keep them cool and comfortable while indoors. Bugs, too, try to get out of the heat, and many bugs are attracted to air conditioners. Learn how to keep bugs out of a central air conditioner and window unit.

    Why Are Bugs Attracted to Air Conditioners

     Some people wonder why bugs would be attracted to air conditioners seeing how these units tend to make noise that should scare away pests. Insects are always on the hunt for new places to make their nests and stay out of the heat, cold, or other undesirable elements in the outdoor environment.

    The cooler air drafts near and around your air conditioning units and ducts can attract many different types of bugs and pests. This is especially true when we’re experiencing extreme temperatures, such as what this country has seen this past summer.

    Along with providing these nearby outdoor pests with an excellent shelter from the heat, rain, smoke, and other environmental dangers, your home air conditioner can provide a way into your home for these pests as well.

    What Types of Bugs Can Come Through AC Units

     All different types of bugs are known to come inside a home through the AC units. Even in larger cities with many apartment buildings, maintenance workers often find that these pests can enter a building through tiny cracks and holes in air conditioners and ductwork to spread from one unit to another once inside. 

     The types of insects encountered inside air conditioners include:

    • Flies
    • Mosquitoes
    • Roaches
    • Termites
    • Ants
    • Spiders
    • Water Bugs
    • Beetles
    • Stink Bugs
    • & Many More

     The facts are that many different types of bugs can and do get inside through air conditioning units and HVAC systems.

    Prevent Bugs From Coming Through Window Air Conditioner

     The best way to resolve an indoor bug infestation problem is to figure out how these pests have gotten into your home in the first place. Many homeowners neglect to consider the air conditioning units as a possible mode of entry for these pests.

    There are some terrific ways to prevent these bugs from coming through a window air conditioner that should be considered by all homeowners worried about pests getting inside the home.

     Inspect the outside of a window air conditioner unit and look for any gaps, holes, cracks, or other openings. Remember that small insects only need a tiny space that may even be too small for the average person to see with just their naked eyesight.

     It is best to completely seal all around the unit between the air conditioner and the window of a home where the unit is placed.

    Seal the Spaces with Duct Tape

     Duct tape can seal off smaller holes and cracks quite effectively around an AC unit. There are usually extension pieces on the sides of window air conditioners that make the air conditioner fit tight within the window frame. Then, seal all around the unit with common duct tape found at your nearby hardware store or home and garden store department.

    Use a Good Caulking Agent to Seal Holes & Gaps

    Use caulking to seal holes and gaps

     Caulking around the outside frame of a window-based AC unit is more effective than just tape that will tear and loosen over time spent in the elements. Caulking can get those minuscule holes and cracks and fill them in tight so no bugs can wiggle their way inside.

    Use Cardboard to Seal Cracks

     If you have no other materials on hand and want to use a stopgap measure of keeping bugs away, you can use cardboard pieces to close off larger sections of gaps and holes surrounding a window air conditioner. Carboard can keep bugs back, but this is only a temporary solution. 

     Cardboard will get wet and soggy due to rain, snow, or high humidity levels, and this can cause it to crumble and allow spaces where bugs will find their way indoors.

    Build a Wooden Frame to House the AC Unit

     Building an actual wooden frame to house your AC window unit properly is a better option. Of course, there will still be slight gaps that can be filled in with caulking or tape. This is a relatively inexpensive solution for getting a window-based air conditioning unit to fit better.

    How to Keep Bugs Out of a Central Air Conditioner

     It can be somewhat more difficult to seal off a central air conditioner or HVAC unit so that bugs do not get inside. This is due to the larger size and more vents and openings that are around the unit. However, there are some things to try that can be effective.

     Many pests find the grille vent covers to be an excellent place to be their next new home and shelter. Through these grills, the pests can then move into the interior duct vents and pipes that take the cooled and warmed air from outside throughout the rooms of the entire house.

    Filling In Noticeable Holes & Cracks with Concrete or Caulking

     Just like with window air conditioners, you can caulk around the outer edges of a central air conditioning unit as well. Doing this right away before you run the unit can prevent a multitude of pests from getting inside.

    Keep the Area Surrounding Your Central AC Unit Clear from Debris

     One of the biggest problems of bug infestations through a central air unit is that debris and tall grass or bushes often block the unit and provide an excellent entryway for the pests to enter your unit and home.

    Keep the landscape looking neat and be attentive to the areas surrounding your central air conditioner or HVAC unit.

    Stop Water Leaks & Clean Gutters

     Many bugs are attracted to water, so homeowners should stop any water leaks outside the home and seal them with caulking or replace broken rain gutters or spouts. It is important too to clean out your gutters regularly.

    Consider Installing Special Screens

     The best way to protect your home from uninvited pests that enter through the AC unit is to invest in special screens to keep these pests out. Screens can be ordered through home and garden centers, and homeowners can hire contractors to install these screens for them.

     Screens can also be custom fitted to your exact needs.


     It only takes a small amount of preparation to rid your AC units from bugs seeking to enter your home. It is also a good idea to have an actual AC Unit expert inspect and provide you with the best remedy for your unique home.




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