Don’t Let the A/C Slip Away: How to Insulate Your Home for Summer

Even though the temperatures outside vary greatly from winter to summer, the tasks for insulating in summer and winterizing in the cold are quite similar. The main difference is what we call it – in the winter, it’s “winterizing.”  In the summer, it’s “weatherizing.” recommends paying attention to several areas of your home while weatherizing. From air sealing to improving ventilation to adding insulation, home weatherization helps consumers save money by saving energy. Remember the point is to keep the cool air inside in the summer and warm air inside in the winter.. If you recognize these needs in your home, but don’t have the time or expertise (or desire) to take this on, a certified contractor will be happy to help you.

Insulating Your Home

Insulating in the following areas may be the best way to improve your home’s energy efficiency this summer:

  • Attic – this includes insulating either the floor of the attic or under the roof.
  • Walls – insulate all exterior walls, including walls between living spaces and unheated garages, as well as foundation walls above ground level and foundation walls in air-conditioned basements.
  • Floors – Add extra insulation along floors above hot spaces, such as vented crawl spaces and unheated garages. Also insulate any portion of the floor in a room that is cantilevered beyond the exterior wall below.
  • Basement – Try your best to insulate all exterior walls, as well as exposed pipes to keep heat in or out.
  • Crawlspaces – Areas under your home are hard to insulate, but try to add a layer of insulation between the heat in the crawlspace and your living or air-conditioned areas.

Air Sealing

Test your home for air tightness. It’s important to seal any leaks to the outside – it saves you money in utility bills and it also saves energy and power. Focus on these areas:

  • Dropped ceilings – the space in a dropped ceiling between the ceiling and the roof can collect and hold lots of hot air (from outside) or cold air from the interior of the home. Seal it properly and reduce the amount of energy used to cool that unused area of your home.
  • Recessed lighting – seal around the lighting can as A/C can easily flow through these cracks and into the attic or between the floors.
  • Attic entrances – you would be amazed at how much air escapes through the attic door and into the attic.
  • Sill Plates – a sill plate or sill is the bottom horizontal piece of a wall or building to which vertical pieces are attached. Gaps between the sill and the wall lose a lot of air.
  • Water and Furnace Flues – seal flues at their attachment points and any place they pass through a floor or ceiling to ensure air does not escape in these areas.
  • All Ducts – Few homeowners realize how much air escapes through unsealed HVAC ducts. A thin bead of caulk between the vent and the ceiling can make a huge difference.
  • Chimney Flashing – cap the chimney and check for cracks or other areas where air can escape. Be sure to keep the flue closed during the summer.
  • Window and Door Frames – if you have single pane windows, you might want to consider upgrading to double pane with nitrogen infused between the panels. All door frames should be inspected. If you can see light around the doors or windows, air is certainly escaping.
  • Outlets and Switches – Especially those on the outside walls, a foam gasket and calking can be used to seal around the electrical box. A child safety plug can also be used to seal the actual plug holes.
  • Plumbing and Utility Access – any hole cut into the house or crawlspace for piping is a potential area for seepage. Be sure to have those caulked or sealed tightly.


It’s very important to ensure your home is sealed properly. It’s also important to ensure you have the proper ventilation. A completely air tight home can seal in indoor air pollutants and moisture from condensation and daily living. Vapor barriers can help prevent moisture problems, increase energy efficiency and improve comfort in your home.



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