MacroFlo opening type affects external conduction gain?

Works in conjunction with ApacheSim to provide bulk airflow analysis for passive/hybrid ventilation system design and simulation.
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enerGwizz
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MacroFlo opening type affects external conduction gain?

Post by enerGwizz »

I'm relatively new to using MacroFlo, and getting familiar with how it works by slowly changing things.

I've copied a space to a location sufficiently distant enough that the two spaces are not affecting each other. For one space, I left the openings as the default "external window opening" where it has 0% openable area. On the other space, I added an operable window but assigned a continuously OFF schedule.

After running Apache, I can confirm that the MacroFlo ventilation for both is zero, and all the sensible gains in the space are equivalent except for "external conduction gain" and "internal conduction gain."

Again, the spaces are exact copies of each other and I'm only changing the opening type (not any construction properties). What would cause the conduction gains to be affected with such a change?

Thanks in advance.
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PCully
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Re: MacroFlo opening type affects external conduction gain?

Post by PCully »

Hi,

I'm sure there is some reasonable explanation for this. Check that the opening types are the same other than the profile, specifically I'm thinking along the lines of Crack flow and length.

You would be able to check the MacroFlo results in Vista for each room if you have that switched on in Simulation Settings output options so this would show if it is consistent every day or only at certain times. If the MacroFlo gain is different for the rooms this would certainly explain the discrepancy in resultant Conduction gains as it will affect space temperatures.

By the way I'm pleased to hear you are taking a trial and error approach to this, I have always found this is the best way to learn aspects of VE and impact of different inputs and for testing something like MacroFlo it can be quite fun to see the effects in the result and consider the real life implications. MacroFlo Arrows in VistaPro is a great visualisation aid

Phil

Phil
IES Worldwide Technical Support
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