VAV with electric heat coil

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Hi All,

I am trying to model a package roof top VAV unit with electric heat coil.

At system level heating I selected:

System type: Pkgd Var Val
Heat source: furnace
Zone heat source: Electric (each zone has a VAV with electric heat coil, EAT=55, LAT=85)
Heating capacity:-220 MBH (same as my mech sch. For RTVAV)

At zone level I think I have to enter heating capacity or reheat delta T, but both of them are n/a.
How can I get this one fix?

On my previous model, I modeled the electric heat coil as a baseboard in each zone!!!
I am not sure if I did it correctly because at the end my space heating on baseline was very low compare to proposed and made energy saving percent equal to -97%.

Thanks in advance for your help

Arash Pasgar

Arash's picture
Joined: 2012-05-16
Reputation: 0

If I am not correct, you would enter the reheat delta T at the SYSTEM level. Try that.

John Aulbach

John Aulbach's picture
Joined: 2011-09-30
Reputation: 1

John, you are correct. REHEAT-DELTA-T is set at the system level and
applies to all zones on that system. The ability to meet the heating
load will depend on the minimum flow during heating mode and the
reheat delta T.

Note that PVAVS and VAVS do not necessarily deliver the minimum
supply air temperature specified. This may skew the relative
gas/electricity heating energy results one expects.

Chris Jones's picture
Joined: 2011-09-30
Reputation: 0