How to Prepare for an Infra Red Thermal Imaging Survey
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Thermal Imaging is often used to identify and highlight areas of heatloss in buildings, in order to improve or correct insulation. In order to visualise this heatloss successfully, we need to fulfil two criteria:
  1. The survey must be carried out at night. This is because during the daytime, sunlight (both direct sunlight and sunlight that has been diffused through cloud) causes infra red reflections on the property which can mask the subtle emissions we are looking for, and it can confuse the picture, as parts of the structure that emit heat may also absorb heat well, and so in daylight they show up much darker than areas of the building that reflect light well.
  2. Ideally the survey should be carried out in cold conditions. The colder the better- as the greater the difference between the exterior of the house and the outside air temperature, the more clearly the heat emission will be seen. In practical terms, you won't get much value out of a survey done when outside air temperatures are 12 or 14°C.  Ideally, you want the survey done when outside temperatures drop to 6°C or lower.

Booking a Thermal Survey


If you wish to book a thermal survey, please contact us via email to arrange a suitable date/time. We offer low-cost thermal surveys, however, this means that a significant proportion of the cost is due to mileage charges (unless you are close to our office). For this reason, it is much more cost-effective if we can carry out two or more surveys within a 50mile range. If you have a friend or relative that may also be interested, it makes sense to try to book together, or alternatively, let us know and we can delay your survey until someone else in your area requests a survey, to save costs.


Preparing for a thermal Suvey

Surveys will normally be carried out during the winter months - between 1st October and 31st March, however, there is no hard-and-fast rule. If the temperature is suitably low we can do the survey at any time of year. We do need to wait until it gets dark, though, so we will carry out the survey during the evening.

In order to maximise the difference in temperature between the building and the outside air, we recommend that the house is heated prior to our visit. Ideally, the house should be heated for 10-12hours to a comfortable room temperature (18-20°C), but particularly during warmer weather, there may be extra benefit in heating the house to a higher temperaure - say 25-27°C. It is important that the house is heated for several hours prior to our visit - this allows the fabric of the building to warm up, which requires considerable time. It also allows any heat losses in the ceiling of the upper floor to heat the attic sufficiently to show up minor heatloss through the roof covering.


The Survey

We will photograph your property with our thermal imaging camera from various angles at front and rear. The survey does not take very long, and we would normally expect to produce around 10 good quality images of the building. Other areas of interest may also be photographed at the same time if required (eg underfloor heating system, boiler, hot water cylinder, insulated pipes etc). We generally aim to complete the survey in around 30-60minutes.


Post-processing the images


The images will not be available immediately. These need to be downloaded from the camera, and then converted into jpg images. The images are store in the camera in a special thermal-image format, which allows the image to be post-processed by computer. The post-processing is a simple, but time-consuming task. If you prefer us to do this, we will process the 10best images and forward these to you by email, or downloaded from our webspace. If you prefer, we can provide the image-processing software so that you can process the images yourself, in which case we will provide all the images we have taken of your property (typically 30-40images). The only condition is that you delete the software from your computer once you have processed the images.

thermal_imaging_daytime_front_of_house2.gif
Thermal Imaging of the same house taken during the daytime (above) and on a cold night (below). The image above, despite being taken on an overcast day, simply shows how different areas of the house either reflect or absorb sunlight. However, the nighttime image below visualises the actual long-wavelength thermal emissions of the house itself, and heat leaking from areas of the main roof is clearly evident.
  thermal_imaging_night_heat_loss.jpg






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