Our project coordinator CSTB has developed a breaking method to accurately asses the thermal performance of a building envelope!
The SEREINE protocol has been deployed on 3 pilot sites of the EPC RECAST project in France, including the apartment below in Mignovillard (North-East France).
This test method aims to provide a measurement in a short time (12 to 72 hours) to accurately characterize the thermal performance of the building envelope.
The principle of SEREINE is to apply a controlled thermal supply inside the building and measure its thermal response (see pic!).
HOW?
The tested building is monitored using a dedicated kit consisting of electric heaters, indoor and outdoor temperature sensors, and a weather station. The measured data is then used in an inverse method process for parameter estimation and calculation of the heat transfer coefficient Htr (that represents the actual level of insulation of the building envelope).
WHAT DOES THE SEREINE PROTOCAL CHANGE?
In Mignovillard, during the on-site visit, the recruited energy assessor estimated the Htr coefficient at 55 W/K, which led to an annual energy consumption of 166 kWh/m2/year.
The SEREINE protocol proved that the Htr coefficient measured 30 W/K leading to an annual energy consumption of 126 kWh/m2/year, reducing the calculated energy consumption by 25%.
The EPC RECAST project demonstrated the performance gap between measured and predicted heat loss.
Sources of deviation between the actual and expected performances can be attributed to the design phase (limitations, inaccuracies and assumptions in the numerical models used to predict the energy performance), the construction phase (quality of workmanship and differences between assumed and actual installed materials, components and systems) and the operation phase where the user behaviours may differ from the expectations.
This example shows the potential benefits of complementary envelope performance measurements.