engleski

Review and comparison of current experimental approaches for in-situ measurements of building walls thermal transmittance

Identifying the actual thermal performance of a building envelope is crucial for energy audits when decisions are made concerning energy refurbishment and implementation of energy- saving measures regarding appropriate and cost- effective building technology selection. It has been shown that in- situ measurements are very useful for determining the actual thermal performance of building elements within existing buildings, particularly since values determined on site in real conditions can significantly vary from theoretical values affecting actual building performance, and laboratory methods have limited application in existing buildings. Owing to the observed limitations of the commonly used heat flow metre (HFM) method, new and alternative methods for conducting in-situ measurements of thermal transmittance (U-value) have been proposed in the last few years. These efforts have recently resulted in standardisation of the infrared thermography (IRT) method for conducting in- situ measurements of the U-value. This paper presents an overview of the current and most commonly used experimental in-situ approaches for determining the U-value of building walls and provides a comparison between internationally standardised and alternative methods. Each method is evaluated with its advantages and disadvantages, limitations, reported deviations and the measurement procedure employed. A comparison between the most significant existing in-situ methods used for measuring the U- value is presented with the aim of assisting researchers to select an appropriate measurement procedure to employ.

Building technology ; In-situ measurements ; Thermal transmittance (U-value) ; Building walls

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