HAP VAV Heating question

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When I choose VAV system type in HAP, I get 3 options which are VAV, 1 Fan Dual Duct VAV and 2 Fan Dual Duct VAV.

I want to design a VAV system but with central cooling AND heating. When I use VAV, it doesn't give me the option to use central heating and I'm forced to use a VAV box with reheat instead. Is there any work around this?

Can I add the total of the terminal heating coil for each zone and just place a central heating coil with the same amount?

Thanks in advance.

Ahmed Kamel's picture
Joined: 2016-05-18
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The option isn't there for VAV because you typically don't want to have
central heating from a single duct VAV system - if you did you would lose
the option of providing simultaneous cooling in some zones and heating in
others. If you didn't plan on having simultaneous heating and cooling,
there is a type of system called VVT (Variable Volume and Temperature) which
switches back and forth, I think they are only used on smaller projects
because you sacrifice a level of comfort.

I think a more common type of system today would be a true VAV system with a
separate perimeter heating system either through baseboard heaters or
fan-powered boxes these options are available when VAV is selected.


Aaron Smith, P.Eng
M&R Engineering

Aaron Smith's picture
Joined: 2011-09-30
Reputation: 0