Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question
1

How to develop an Epw file about solar-air temperature

asked 2019-07-11 01:04:40 -0500

walk_er gravatar image

updated 2019-07-11 13:51:54 -0500

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!

edit retag flag offensive close merge delete

1 Answer

Sort by » oldest newest most voted
1

answered 2019-07-11 12:37:51 -0500

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.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

 



Question Tools

Stats

Asked: 2019-07-11 01:04:40 -0500

Seen: 26 times

Last updated: Jul 11