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

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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JustinLueker

asked 2017-11-10 14:27:41 -0500, updated 2017-11-13 13:51:19 -0500

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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 (2018-01-23 06:58:52 -0500) edit

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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:

constant value
time-based schedule of values
custom curve of values (defined by SurfaceConvectionAlgorithm:Outside:UserCurve or SurfaceConvectionAlgorithm:Inside:UserCurve object)
same overall models used by SurfaceConvectionAlgorithm:Outside and SurfaceConvectionAlgorithm:Inside objects (Simple, SimpleCombined, TARP, AdaptiveConvectionAlgorithm, etc.)

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.