Why Is There No Heating Capacity in PVAV Zones When Converted From PSZ in Detailed Edit?

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Everyone, I converted a model with a bunch of Pkgd Single Zone units
(furnace heat, DX cooling) to a Pkgd Var Vol system (electric heat, DX
cooling) with zones in Detailed Edit. The converted program ran but the
unmet heating hours increased greatly. I checked the new PVAVS zones,
and they are grouped correctly under the Pkgd Var Vol system, but the
program is not assigning any heating capacity to the individual zones. I
checked the heating capacities in the SV-A reports and all of the zone
capacities are 0. I then built a Design Wizard Pkgd Var Vol model and
started comparing the HVAC navigation tree screens to the Detailed Edit
converted model HVAC navigation tree screens and found some
discrepancies. I found that the converted Detailed Edit zones lacked the
minimum flow ratio (0.3) so I added that in. I also discovered that the
thermostat type didn't convert to Reverse Acting so I fixed that. I
don't see any other differences between the Design Wizard HVAC
navigation tree screens and the converted Detailed Edit HVAC navigation
tree screens, and yet the fact remains, I am not get any heating
capacity to show up in SV-A in the Detailed Edit converted model. So,
there is something else I need to change, but I can't think what.

Has anybody run across this problem before and has a solution?


Kathryn Kerns

Kathryn Kerns's picture
Joined: 2011-09-30
Reputation: 0

Double check that your zone reheat entry has a value like 30 degrees, or
something around that value.

James Hansen, PE, LEED AP

James Hansen's picture
Joined: 2011-09-30
Reputation: 200