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Changing composition of atmosphere in EnergyPlus (e.g. increasing CO2 concentration) to simulate effect on envelope convection

asked 2017-11-10 14:27:41 -0600

Lueker gravatar image

updated 2017-11-13 13:51:19 -0600

As a "fun" project, I'm seeking to simulate the thermal performance of a building envelope in a theoretical atmosphere composed entirely of CO2.

Can EnergyPlus model the resulting effects on interior/exterior convective heat transfer coefficients, say, for blustery conditions in my CO2 atmosphere?

Perhaps a weather file can be manipulated, or convection inputs adjusted, to simulate the effects of this atmosphere?

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I don't see the point of this exercise. If the atmosphere is composed entirely of CO2, it would be an alien atmosphere so extreme that would make manipulation of a weather file pure conjecture. Even Venus "only" has a CO2 concentration in the 30% range and already the extreme greenhouse effect results in temperatures that would melt lead. Under those circumstances, adjusting convection coefficents is the least of your problems.

Joe Huang gravatar imageJoe Huang ( 2018-01-23 06:58:52 -0600 )edit

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answered 2017-11-16 15:02:28 -0600

EPW files are essentially rearranged TMY files, and I don't see anything in the TMY-2 data elements or TMY-3 user guide that correlate to atmospheric composition of air vs. CO2 and resulting change in convection coefficient values. As such, I would recommend adding the SurfaceProperty:ConvectionCoefficients object to your IDF, which can allow users to set interior and exterior convection coefficients using multiple options:

Note that this convection coefficients object can only be applied to a single surface.

The SurfaceProperty:OtherSideCoefficients object is another option, but it can only override exterior surface convective heat transfer coefficients and/or air temperatures.

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Asked: 2017-11-10 14:27:41 -0600

Seen: 95 times

Last updated: Nov 16 '17