Coheating testing is a means to compare the thermal performance:
Coheating testing is also a vital component of many Post-Occupancy Evaluations: these best practice checks are increasingly being undertaken to understand whether a building, in its constructed rather than theoretical state, is fit for purpose.
Through coheating testing, Stroma Tech can determine a ‘real life’ whole building heat loss rate: this rate is linked to thermal losses through the fabric, plus losses from air-leakage.
Stroma Tech was one of the first commercial testing organisations to undertake coheating tests in the UK. We have performed tests on private residences, Technology Strategy Board-funded retrofit projects, and social housing retrofits to evaluate the effect of the improvements undertaken.
All ventilation points are temporarily sealed prior to commencement of the testing.
Electric heaters, axial fans to agitate the air, and thermocouples are all spaced evenly throughout the property and connected to a modem-enabled data logger. Where required, heat flux sensors for party walls are also installed.
To monitor the weather conditions, an external thermocouple, anemometer and pyranometer are installed externally.
With equipment installed and operating, the thermostats are all set to a temperature (nominally 25°C). The equipment continually records all the readings for temperature (internal/external), energy use, solar irradiance and wind speeds. The recommended minimum period of monitoring is 7 days, which requires an initial 3-day set up.
The data collected is used to calculate the thermal coefficient of the building, which encompasses all envelope elements including roof construction, wall construction (incorporating doors and windows) and floor construction, etc.
The results are used to prove actual fabric performance and used as a basis to compare dwellings.