How to Find Cold Spots in Your House [11 Quick Steps]

To quickly and accurately find cold spots in your home, use a thermal leak detector. It will show you temperature differentials where heat is escaping your home. Begin by scanning common areas where heat is lost through the ceiling, including at the upper corners of rooms and around attic hatches. Then, work your way downward. Scan around windows and exterior doors, switchplates on exterior walls, and baseboards. Follow up by scanning the area where any vents or service lines pass through your wall to the outdoors. Then, walk barefoot through the first floor of your home. Especially cold portions of the floor may be a sign that cold air is infiltrating from below.

How to find cold spots in house

Why Are There Cold Spots in Your House?

Cold spots in the home are commonly caused by gaps that allow hot air out or cold air in. A small gap where your dryer vent or cable line passes through your wall to the outdoors can allow large volumes of heated air to leak out of your home. Uncaulked windows or doors with worn-out weatherstripping also cause gaps that bleed heated air. This air exchange creates corners or entire rooms that are much colder than the rest of your home.

  • Gaps, where cold air can seep in, are a common cause of cold spots.
  • Common cold air infiltration spots include around doors, windows, or utility lines that pass through an exterior wall.
  • If your ceiling, wall, or floor doesn’t have enough insulation, it can cause a cold spot in your home.
  • An uninsulated floor above a basement or crawl space can cause certain areas of your home to be much colder than others.

Inadequate insulation is another common cause of cold spots in your home. A lack of insulation near a switchplate installed in an exterior wall can allow cold air in. So can thin insulation in your ceiling, or in your floor. It’s important to keep in mind that cold spots can be caused by cold air leaking in from above, below, or through the walls.

Use the 11 steps below to find cold spots in your home, or find an HVAC technician in your area to help.

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11 Steps to Perform a Cold Spot Inspection for Your House

Air leaks and lack of insulation can cause uneven temperatures in your home. Your indoor temperature may plummet if the room has a cold spot. Plus, cold spots are a sign that the air you are paying to heat is escaping to the outdoors. Finding cold areas will help you make your home more energy efficient and save you money. Here’s how to do your own cold spot inspection at home:

Invest in a Thermal Leak Detector

To find cold spots in your home, begin by purchasing this thermal leak detector. This tool will pay for itself by helping you find and fix areas where hot air is leaking out of your home. Closely review the instructions for the thermal leak detector you choose so you will be able to tell at a glance when your tool has detected a sudden change in temperature. You will use your thermal leak detector for almost all of the following steps.

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Scan Ceiling Fixtures

You may have heard that hot air rises. Since this is true, it’s essential to check if hot air is rising and leaking out of your home. Scan your ceilings with the thermal leak detector. Move the scanner along corners where the ceiling and wall meet, to find cold spots. Then, scan around attic access hatches and ceiling light fixtures. Sometimes, warm air can seep out around these installations. If this is happening in your home, your thermal leak detector will find the problem areas.

Check Around Windows and Exterior Doors

The areas around doors and windows are prone to heat loss in the winter, which causes cold spots in your home. So, it’s essential to check these common problem areas. Scan around the frame of doors and windows to check for cold areas. It’s also a good idea to hold the back of your hand up to any cracks or seams you spot. You may be able to feel cold air blowing in around a window that hasn’t been caulked recently. Keep in mind that window panes are often colder than the surrounding wall. Scan the wall itself, not the glass of the window.

Take a Closer Look at Switchplates

Switchplates and plugs in exterior walls can easily cause cold spots in your house. This is because the insulation in your wall must be carved away to make room for the electrical installation in the wall. Scan around light switches and plugs in your exterior walls. If there is a drop in temperature in these areas, insulate your plugs with these insulation pads. They install in minutes and keep cold air out.

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Scan Your Baseboards

Gaps along your baseboards can allow heated air to escape or cause cold air to blow into your home. So, make sure to take a closer look at your baseboards. If your thermal leak detector shows lower temperatures along your baseboards, make plans to caulk the gap between the baseboard and the floor. This can eliminate cold spots in your home and reduce your heating bill.

Test the Area Around Vents

Vents that pass through your wall or ceiling to the outdoors can allow cold air infiltration. From inside your home, find where your dryer vent passes through the wall to vent air outside. Then, scan this area. Just make sure your dryer is not running, since the heated air passing through the vent could give you a false reading. If temperatures are colder around this vent, it means cold air is seeping through the gap between the sides of the vent and the wall. Injectable foam insulation or caulk will help seal this gap.

Check for Cold Spots Around Service Lines

Similar to vents that pass through walls and ceilings, pipes, cables, and telephone lines can let cold air into your house. These openings may seem small, but even the small hole drilled to run an ethernet cable through an exterior wall can let in enough cold air to cause a cold spot. If these areas trigger a cold reading on your thermal leak detector, it’s time to caulk around these service lines.

Don’t Skip the Fireplace

Fireplaces and chimneys can become the cause of cold spots, rather than the heat source they’re meant to be. First, scan the exterior and interior of your fireplace with a thermal leak detector. Then, make sure the damper is closed and put your hand inside the fireplace to feel for cold air. If your damper is working improperly, you may feel cold air or even a small breeze. If you have any reason to believe cold air is leaking into your home through your chimney, contact a professional chimney service for repairs.

Use Smart Heating Technology in Vulnerable Areas

If you aren’t able to find the cold spots with a thermal leak detector, place a few of these sensors from Vivint in colder areas of your home. When paired with this smart thermostat, a signal is sent to increase the heat in your home if it gets too cold. Determine which sensor sends the signal to find the cold spot in your home.

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Walk Barefoot

Even though it may be cold, take a barefoot walk around the first floor of your house. Walk carefully and walk to every corner of each room. Take note of places where the floor feels noticeably colder or has wet condensation. This can indicate cold air leaks from below. These are areas where you need to provide more floor insulation, to stop cold air from entering your home from the floor.

Check Your Roof After it Snows

If you live in a region with winter snow, you can check for cold spots after snowfall. Take a walk around your house the morning after it snows. Look for patches on your roof where the snow has melted away. This indicates that warm air is leaking out of your roof, rather than staying inside your home. Take photos of these areas. You will need to install additional insulation in these sections of your ceiling to prevent heat loss and eliminate cold spots.

How Do You Fix Cold Spots in Your House?

Cold spots in your home can be resolved by caulking gaps that allow air infiltration and adding insulation where necessary. Caulking around windows, doors, service lines, and vents can save you a lot of money on heating your home in winter. Plus, you won’t have those pesky cold spots in your home.

  • Caulk around doors, windows, and attic hatches.
  • Replace the weather stripping on exterior doors and interior attic hatches.
  • Use foam sealant or caulk to seal around service lines, vents, plumbing, and wires that pass through exterior walls.
  • Add insulation behind switchplates and plugs.
  • Install thick insulation in walls, floors, and ceilings.

Insulating your attic, crawlspace, or basement can be quick if the space is unfinished. An extra layer of insulation increases hot air retention in winter and traps cool air indoors in summer. If your thermal leak detector identifies cold spots on exterior walls, you can even insulate your walls without removing the drywall.

How Do You Find Cold Spots in Your Home?

Finding cold spots and working to correct them is quick and easy with the right process. To do the job:

  • Purchase an inexpensive thermal leak detector.
  • Start by scanning ceiling corners and around attic hatches for cold spots.
  • Check for gaps and air infiltration around windows and exterior doors.
  • Scan the area around switchplates and plugs to see if they are allowing cold air to leak in from outside.
  • Check along baseboards to see if cold air is leaking in through the gap between the baseboard and the floor.
  • Scan around dryer vents that pass through walls—cold air can infiltrate around the edges of the vent.
  • Look for gaps where pipes or cables pass through the wall from the outside.
  • Inspect your fireplace for cold spots or cold air coming down the chimney.
  • Install a smart thermostat and sensors to determine the vulnerable area in your home.
  • Walk barefoot on the first floor to find especially cold areas where air may be infiltrating from below.
  • After a snowfall, walk around your house and look at the roof. Areas, where the snow has melted, may indicate warm air is leaking out through a poorly insulated roof.

By scanning these problem areas for uneven temperatures, you can easily locate cold spots. By pinpointing the cause, you can also identify the fix. A cold spot caused by a leaky window or dryer vent can be fixed with caulk, while cold spots caused by a poorly insulated floor or ceiling can be corrected by adding more insulation to your home.

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