FLIR Extech i5, User Manual

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15.5 Draft
General Draft can be found under baseboards, around door and window casings, and above
ceiling trim. This type of draft is often possible to see with an infrared camera, as a
cooler airstream cools down the surrounding surface.
NOTE When you are investigating draft in a house, there should be sub-atmospheric pressure
in the house. Close all doors, windows, and ventilation ducts, and allow the kitchen
fan to run for a while before you take the infrared images.
An infrared image of draft often shows a typical stream pattern. You can see this
stream pattern clearly in the picture below.
Also keep in mind that drafts can be concealed by heat from floor heating circuits.
Figure
The image below shows a ceiling hatch where faulty installation has resulted in a
strong draft.
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Publ. No. T559382 Rev. a358 – ENGLISH (EN) – June 23, 2009
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15 – Application examples