7. Thermal Imaging, windows and boilers

A thermal image camera survey – what’s it all about?

◻︎   A thermal image camera uses infrared and if you point the camera at your outside walls it will identify cool areas and hot spots.

◻︎   It’s best to do the survey on a really dry and cold winter’s night, when there hasn’t been too much direct sun during the day, and with the heating turned up full blast. That way the camera can do its best work.

◻︎   The camera can be really good at finding hot spots in the outside walls, windows and dormers where there is poor insulation or where relatively warm air is leaking out of the house especially at holes and gaps.

◻︎   It can be a really useful initial diagnostic tool for prioritising where to spend your time and money.

◻︎   The Transition Lymington team can arrange to carry out a thermal image camera survey and give you key infrared photos. This will help you prioritise what to take forward.


Next Steps

•Start with reducing the air leakage from your home using our tips (postcard 1).
•Sort out your TRV’s together with your boiler controls and programming (postcard 2).
•Then increase your loft insulation to 27cm (postcard 3).
•Then get in touch with the Schools Energy Project, Lyndhurst to arrange a Thermal image camera survey of the outside of your home. This will show in graphic relief (in yellows and reds to be exact) where the shortcomings are.
•Not only is this good at showing where wall insulation is missing, it can also highlight where warm inside air is finding an escape route to the outside.
•On older properties for instance, warm internal air can leak into the cavity, first finding gaps under skirting boards (postcard 1) and then gaps around the ends of floor joists where these are built into the cavity wall. Gaps in the insulation within the cavity will act as air pathways for the heat to travel and escape.

Steamy Windows

Air leaks, plus heat radiating out from the window glass and frame, can be significant.

Vacuum seals of the double glazing may start to fail – this will become apparent initially during cold weather as condensation forms within the unit vacuum seal (over time this will become very obvious as a permanent misting). However, remember just about anything is repairable (there are specialists who do this all the time) including replacing sealed glass panes!


Make use of timer controls for your boiler so that your heating and hot water, are only coming on when you need them. Make regular adjustments as the season gets colder, and then warmer again.

Do you have a condensing combi boiler? If so, you can reduce the boiler flow temperature to save energy. Go to www.theheatinghub.co.uk . Then to ‘Reduce your gas bills by 18% now’ which explains what type of boiler set-up you need to be able to do this.

Some modern boilers have ‘eco’ and ‘preheat’ modes which you should find out about from the user manual for your hot water.