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How to develop an Epw file about solar-air temperature

asked 2019-07-11 01:04:40 -0600

walk_er's avatar

updated 2019-07-11 13:51:54 -0600

Hello everyone! I expect to use EnergyPlus to study natural ventilation in buildings. In my research, the air temperature of outdoor air (To) and the solar-air temperature (Tsol-air) are a harmonic function of time with angular frequency ꞷ (To=To+ΔTosin(ωt+φ), Tsol-air=Tsol-air+ΔTsol-airsin(ωt+φ)). So I have to develop an EPW file. At present, I know that Elements can modify the outdoor air temperature (To), but I have no idea whether and how the solar-air temperature (Tsol-air) could be modified in Elements. Does anyone know how to do it, or are there any other ways to achieve my purpose? Thank you in advance for answering my question! I am looking forward to your reply!

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answered 2019-07-11 12:37:51 -0600

Sol-air temperature is meant to be used as a predictive variable for cooling load. It is a combination of several variables into one for use in simple statistical models of cooling load. EPW (energyplus weather) files include temperature and solar data separately, and the simulation uses each of these data explicitly. There is no sol-air temperature in an EPW file.

If you are trying to mimic an EPW file, you could use the explicit calculation of solar air temperature to back-calculate the irradiance values to use in the EPW file.

I think a much more appropriate thing to do would be to use an existing weather file and then fit the parameters in your harmonic function to match to the outdoor air temperature and solar-air temperature calculated from data in the EPW file.

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Asked: 2019-07-11 01:04:40 -0600

Seen: 208 times

Last updated: Jul 11 '19