Junghun Lee

Appropriate conditions for determining the temperature difference ratio via infrared camera

The temperature difference ratio is used to measure the thermal performance of a building envelope. Calculation of temperature difference ratio requires temperature differences between indoor and outdoor environments and wall surface temperatures, obtained here using an infrared camera. This approach performs well when the temperature differential between indoor and outdoor environments is greater than 10℃ and when wind speed is less than 3.0u2009m/s. We identify periods suitable for accurate evaluation of thermal insulation performance with an infrared camera, based on eight cities in Korea. The number of measureable hours ranges between 3183 and 1317 annually. Optimum periods for measurement are between November and March, specifically between 01:00 and 09:00u2009h. Measurements obtained during these periods can therefore be regarded as relatively accurate. Practical application: A thermal imaging camera provides an easy method for checking the insulation performance and construction conditions of a building. Conventionally, this would be checked experimentally, but thermal imaging allows easy visualization of conditions.