Surface temperature of internal blind

grasshopper honeybee-legacy
1

Hi Mostapha, Chris and all,

While investigating the impact of internal blind on occupants’ thermal comfort, I became curious about how we calculate the surface temperature of internal blind. Is it something that I can check in Honeybee work flow?

I understand that we can calculate surface temperature effect from the Energy simulation results and the HBZone geometry combined with an MRT delta using the SolarCal method in Honeybee. I just wonder that if we assume an internal blind (such as fabric roller shade) is deployed to block the direct solar radiation, how we calculate MRT. I think thermal comfort should be calculated based on the surface temperature of the internal blind, not the glass surface as the surface temperature between blind and the glass could be quite different.

Please let me know if it is already being discussed/ if there is any Honeybee workflow I can follow to get the surface temperature of internal blind.

Thanks,

2

Won hee,
Your assumption is correct. EnergyPlus is actually using mathematical abstraction of the blind, which accounts for the solar energy absorbed by the blind and the resulting increase in it’s temperature. Essentially, EnergyPlus assumes this temperature of the blinds is the interior surface temperature of the window geometry and it uses this blind temperature to compute heat exchange between the closed blind surface and all of the other surfaces of the zone. This also means that the surface temperatures that we are plugging into the comfort maps is the correct one to account for the blind temperature.
-Chris

3

Thanks for your clarification!