Field measurements for estimating the convective heat transfer coefficient at building surfaces

To establish a comprehensive and qualitative prediction basis for the convective heat transfer coefficient (CHTC) for various urban canopy surfaces mainly consisting of building envelopes, a series of outdoor experiments were performed. Multi-point measurements of surface heat balance lead to a distribution of the CHTC on an actual building envelope. Several turbulent statistical values acquired at two different sites enabled the development of an experimental equation depicted by non-dimensional numbers that express a relationship between CHTC and wind velocity containing a turbulent factor. An important thing is the fact that the two measuring sites, one a rooftop slab and the other the vertical wall of a test dwelling, have different scales and different surface directions facing the wind.