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Cambridge Building Energy & Environment Portal

Equipment needed for BE lab.

Task (as outlined in the handout on Environmental Measurements)

The heat exchanges through the building envelope have a significant influence on the environmental performance of an indoor space. The convective heat transfer through the building envelope is assessed in Task V1. This task will therefore focus on the conductive and radiative characteristics of the building envelope including the opaque and transparent elements. The three properties of interest here are: 

1. U-value of the opaque envelope: This quantifies the heat transfer through a unit area of surface due to a 1K temperature difference between the outdoor and indoor environment. This is measured by means of a heat flux meter placed across the opaque building envelope (i.e. indoor and outdoor surfaces) in a location that is not influenced by edge effects (typically no less than 3xbuilding envelope thickness away from any window, pillar etc), together with 2 inside and 2 outside surface temperatures and temperature of the indoor and outdoor environment. The measurement lasts for at least 3 consecutive days.
2. U-value of the centre of glazing of the transparent envelope: Same approach to (1) above.
3. Tsol solar transmission coefficient of the transparent envelope: This quantifies the the amount of solar radiation entering through the façade. It is measured by means of two pyranometers parallel to the glazed façade. One pyranometer is placed in the internal environment and the other one external.

All BE1 measurements (i.e. opaque and transparent parts) can be done simultaneously, the duration of measurement is 3 days minimum. Allow for 1 hour before and after to set-up and remove the experiment.


Coursework Handout

Equipment : 10 Thermocouples, Data logger with expansion module (DT80 + CEM20), 2 Heat Flux meters, 2 Pyranometers.
References : (refer to H1).