If one room in your house always feels colder than the rest, winter may be the best time to find out why.

Thermal imaging is a diagnostic tool commonly used during home energy audits to identify insulation gaps, air leaks, and cold spots. While energy audits can be performed year-round, Maine’s long, cold winters create the ideal conditions for thermal imaging to reveal problems that can be harder to spot in milder weather.

Why cold weather makes issues easier to see

Thermal imaging works by detecting temperature differences on surfaces. When it’s warm inside and cold outside, those differences become much more pronounced.

In Maine, sustained winter temperatures put pressure on a home’s insulation and air sealing. During a cold snap, missing insulation, air leakage, and thermal bridging often show up clearly on an infrared camera. In shoulder seasons, those same issues may still exist, but they’re often subtler and harder to interpret.

That strong indoor-outdoor temperature contrast is why winter is often the most revealing time for thermal imaging.

What an infrared camera actually shows

An infrared (IR) camera doesn’t see air movement or insulation directly. Instead, it shows surface temperatures.

• Cooler colors indicate areas where heat is escaping or cold air is entering

• Warmer colors indicate surfaces that are retaining heat more effectively

For the most reliable results, indoor and outdoor temperatures typically need to differ by at least 15 to 20 degrees. Maine winters regularly meet that threshold, making infrared images easier to read and more meaningful.

Common winter findings in Maine homes

Thermal imaging during cold weather often highlights patterns that are common in Maine houses.

Heat loss at bump-outs or cantilevers

Additions and bump-outs that extend beyond the main foundation are often difficult to insulate well. In winter, missing or compressed insulation in these areas can appear as dark bands across floors or walls.

Cold air leaking where walls meet floors

Colder temperatures concentrated along the base of exterior walls are often a sign of air leakage, frequently at rim joists or framing transitions. These leaks can make floors and nearby rooms feel especially uncomfortable.

Air leakage around windows

Even newer windows can leak air if they weren’t properly sealed during installation. Cold weather exaggerates these leaks, making problem areas easier to pinpoint.

Why winter images are easier to interpret

In cold conditions, thermal images often show deep blue or purple areas that clearly highlight:

• Where cold outdoor air is entering the home

• Where insulation is missing or underperforming

• Thermal bridges in framing, additions, or cantilevers

In warmer months, those same issues may still appear, but often as lighter color variations that are harder to interpret. The problems haven’t gone away. They’re just less obvious.

Blower door testing can help exaggerate air leakage at any time of year and is often used alongside thermal imaging. Even so, winter conditions tend to produce the clearest, most visually striking results.

When to consider thermal imaging

You don’t need to wait for winter to schedule a home energy audit. But if a bedroom, addition, or living space consistently feels colder during Maine’s heating season, winter is often when the clearest answers emerge.

Thermal imaging is most effective when paired with a full home energy audit that looks at the house as a complete system, including insulation, air sealing, ventilation, and moisture control.

Evergreen Home Performance, which has worked with thousands of Maine homeowners since 2006, uses thermal imaging alongside blower door testing and building science principles to help homeowners understand what’s happening inside their walls and why comfort problems occur.

For homeowners interested in learning more, Evergreen offers home energy audits across the midcoast and southern Maine, with guidance on Efficiency Maine rebates and practical next steps.