High unmet hours when selecting VAV system

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Hi,

I'm having an issue where I get a very high number of unmet heating hours
with space temps getting down as low as 33F in January.
This is only an issue when I select "Variable Air Volume" system which I
believe is the correct system configuration. It seems like the system is
just failing to heat the space, but I cannot figure out why. Has anyone
has similar issues modeling a VAV system?

Thanks,

mcamp1206's picture
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Voila !!
Sounds like you need to have a reheat system defined. That happened to me a few times.
John Aulbach, PE
On Monday, March 12, 2018, 1:33:57 PM PDT, Michael Campbell via Equest-users wrote:

Hi,

I'm having an issue where I get a very high number of unmet heating hours with space temps getting down as low as 33F in January.
This is only an issue when I select "Variable Air Volume" system which I believe is the correct system configuration.? It seems like the system is just failing to heat the space, but I cannot figure out why.? Has anyone has similar issues modeling a VAV system?

Thanks,
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John Aulbach's picture
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Michael,
Have you entered input for HEAT-SET-T? If you leave it blank, you don?t get a main air-handler heating coil.
Regards,
~Bill

William Bishop, PE, BEMP, BEAP, CEM, LEED AP | Pathfinder Engineers & Architects LLP
Senior Energy Engineer

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Bill Bishop's picture
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Thanks for the help.
I defined the reheat system and set the thermostat type to Reverse Action
and I was able to get it to work.

mcamp1206's picture
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