Using Thermal Cameras for Home Energy Audits
Thermal cameras used to be specialist tools reserved for engineers and energy assessors. Today, compact handheld units and smartphone-compatible imagers make them accessible to homeowners, teachers, and anyone interested in understanding how energy escapes from a building.
At Philip M Russell Ltd, we use thermal imaging not only for physics demonstrations, but also for home energy audits — a practical way to show how insulation, airflow, and heat loss really behave in the real world.
Why Thermal Cameras Are So Useful
Thermal imaging reveals differences in surface temperature, making invisible problems visible:
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Cold spots caused by poor insulation
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Warm patches from radiators or pipework
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Heat leaking around windows and doors
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Draughts and ventilation paths
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Damp areas where insulation has become wet
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Gaps in loft insulation
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Radiators blocked with sludge or partially filled
It’s an immediate, visual way to understand energy efficiency.
What to Check During an Energy Audit
1. Exterior Walls
Scan from outside at dusk or on a cold evening.
Look for:
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Hot areas on walls → heat escaping
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Cold patches → missing insulation
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Lines or stripes → poor cavity fill
2. Windows and Doors
Frames often leak more than the glass itself.
Thermal imaging can show:
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Heat escaping around the edges
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Draught pathways
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Ineffective seals
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Cold bridges around lintels
3. Roof and Loft
Warm patches on the roof indicate lost heat rising through the loft space.
Inside, cold spots in loft flooring reveal gaps in insulation depth or placement.
4. Radiators and Heating System
A healthy radiator shows even warmth.
Issues appear as:
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Cold bottoms → sludge build-up
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Patchy sections → trapped air
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Cold pipes → blockages or flow restrictions
5. Floors and Skirting
Cold edges or streaks along the floor often indicate draughts, uninsulated voids, or historic floorboards without proper sealing.
Teaching Value – Bringing Physics Home
Using a thermal camera transforms home energy audits into a real-world physics lesson.
Students can explore:
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conduction (heat through walls),
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convection (draughts and airflow),
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radiation (warm pipes or radiators),
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and insulation strategies.
It connects theory directly to familiar environments — instantly meaningful and memorable.
Practical Tips for Accurate Thermal Images
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Perform audits in the evening or early morning when temperature differences are clearer.
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Turn heating on for at least an hour beforehand.
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Avoid sunlight on walls — it confuses the reading.
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Let the camera stabilise for a few minutes before use.
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Always interpret images in context: bright doesn’t always mean “bad,” and cold doesn’t always mean “good.”
The Takeaway
Thermal cameras make energy efficiency visible.
Whether you’re improving your own home, teaching thermal physics, or analysing heat loss for a project, these tools offer clear, accessible insight into how buildings behave.
A small device can reveal big savings — and even bigger learning opportunities.
