“Are we heating the whole neighborhood?!” is something you probably heard as a kid — or have asked your own kids.
Yes, you are, even if your door is closed. Unless your home is hermetically sealed, heated (or cooled) air inside your home will escape.
But the crucial factors are how easily that air escapes, and its temperature.
The First Step
Before you do anything on your own, call your utility company. These companies often offer energy-saving programs to reduce air leaks from your home. Some even include “infiltration” audits specifically to find air leakage.
You might be able to get a free home audit, and even receive a few free products to help keep more of your heated or cooled air inside your house.
If your company doesn’t offer one of these programs, or they come up short on sealing everything, here’s how to DIY.
DIY Home Sealing to Save Money on Heating and Cooling
Depending on your love of DIY and general handy skills, choose from three levels of home-sealing work. If you’re ready to go all-out and slash your utility bills, see the last section for advanced home-sealing techniques.
If you can see light through the edges of your exterior doors, you’re losing air — and money.
To block that airflow, try a draft guard. It’s basically two pool noodles in a pillow case. Adding a bit of rice or dried corn makes the guard a bit heavier and a better sealer. If you have windows that don’t close perfectly, try a smaller version there.
To reduce the amount of heat you lose through your windows, use window wraps. Will a thin sheet of plastic actually reduce your bill? Yes! When properly installed over the trim, the plastic creates an air gap between it and the window, which helps reduce drafts and heat transfer through the window.
I use 3 mm clear plastic trash bags and masking tape. Yes, my wife let me put trash bags on the windows. All in the name of savings!
It’s important to use clear plastic. In the winter, sunlight coming through the windows helps heat both the air gap and the interior of your home. In the summer, dark colors can absorb heat and transfer it into your home, but clear plastic helps keep the heat outside so your home stays cooler.
Look around your attic and basement for blackened insulation, which is a sign of air traveling through it.
(I assume you have insulation — if you don’t, call someone immediately! No door and gap sealing will help you, since you’re losing heat right through the walls.)
Make sure your attic insulation isn’t compressed. The air gaps within the insulation are what keep the hot air where it belongs. Blown-in insulation should be light and fluffy, and batt insulation should lay flat without being cramped or pressed.
Check the door to the attic. Seal the edge with cushion weatherstrips and, ideally, two layers of batt insulation.
Next, find the intentional openings in your home for water pipes, electric, gas, cable and phone service or vents. Ironically, the gas service in my home had the largest completely unimpeded hole in my wall.
Use foam or caulk (or both) to seal these holes both inside and outside. To find these holes, I use the “follow the screams” method. Spiders like to build webs in these openings because of the air drafts. Where you find spiders, you’ll usually find openings.
Advanced Home-Sealing Strategies
Seal everything: doors, windows, crawlspaces and attics.
Pull off the trim from every exterior door and window to see if it’s foam sealed. Builders frequently shim windows and door frames into place, leaving gaps for air to escape. Fill these gaps with foam, then caulk on both sides of the trim.
Buy cheap outlet foam sealers and put them inside all outlets and switches on exterior walls. These are the weakest points of an insulated wall.
If you feel a draft, find it and stuff it closed. Fireplace, range hood, microwave and bathroom vents are all intentional openings for air to escape. If you can, cover these when you’re not using them.
Check your ducts. Many homes have ductwork over and under their interior structures in crawlspaces and attics.
20% or more of the conditioned air in your home never reaches its intended destination or is unconditioned upon delivery. To DIY, use metal tape to seal the joints of the ductwork you can see. Wrap all joints and especially the corners, even if you don’t think they’re leaking air yet.
Don’t use standard tape, duct tape or fiber/paper/plastic tape. These can melt and will wear out quickly in extreme temperatures.
How Much Can You Save?
Energy Star estimates you spend 15% of your heating and cooling costs on air that leaks right out of your house.
At the Energy Information Administration average gas heating cost in the US of $679 a season, that’s $101.85 a year, or $20.37 a month for the five months most people use their heat. If you’re one of the half of Americans who heat with something other than gas, your savings will be even higher.
These repairs will also help you save on air conditioning costs in the summer. If you save 15% of the estimated EIA average cooling bill of $412, that’s about $61 over three months, or $20.33 a month.
After you seal your ducts, if you can keep even just 5% of the air at its conditioned level, you can save $55 on heating and cooling bills.
Combined, a weekend of hunting air leaks with a few dollars in sealing equipment can help you save approximately $200 a year on heating and cooling costs. The best part: These savings repeat, season after season, from the upfront work.
How Much Should You Spend on Home-Sealing Repairs?
These figures are based on averages, though; there’s no easy way to calculate exactly what you and your house will save, which makes it difficult to figure out how much to spend on home-sealing materials.
My rule of thumb is to take the difference between your highest three bills and your lowest three bills and multiply by the promised 15%.
For example, let’s say your lowest bills (most likely March/April and September/October) are each $100, and your highest are each $300. Here’s the math:
$300 x 3 = $900
$100 x 3 = $300
$900 – $300 = $600
$600 x 0.15 = $90
So I’ll likely save about $90 in a year. If I know I’ll live in my house for three to five years, I might be willing to spend double that, since my savings will last at least that long.
If your bills are fairly steady throughout the year, you’ll benefit less from temperature-controlling measures, but it’s likely you’ll still save a few bucks by taking the easiest steps.
Happy leak-hunting and home-sealing!
Your Turn: Have you worked to seal gaps in your home and make the most of your heated and cooled air? Did you notice a difference in your utility bills?
Disclosure: We have a serious Taco Bell addiction around here. The affiliate links in this post help us order off the dollar menu. Thanks for your support!
Cade Simmons works in energy efficiency oversight and has a Master’s degree in Economics specializing in public utility regulation from New Mexico State University.