[Equest-users] Heating mode stuck at minimum flow rate

[Roselin Osser]

Hi folks,

 

I'm modeling a packaged VAV system (PVAVS) serving only one zone.  The
maximum airflow the unit can provide is 450,000 cfm, which I have entered in
as an airflow parameter.  The problem is that whenever the system goes into
heating mode, the total cfm goes to minimum airflow (observed from hourly
output), even when more heating is needed, so I end up with a lot of
underheated hours.  The minimum airflow is calculated from the 10% outdoor
air ratio I have entered.  I have tried adjusting the HMAX-FLOW-RATIO field
to allow the heating airflow to go above the minimum if necessary, but the
field seems to have no effect.  I have a reverse action thermostat in the
zone.  Anyone else run into this?  There must be some other parameter I'm
using that is preventing the field from working.  Any advice would be
appreciated, as I have tried a lot of input variations and none of them
allowed the heating minimum flow to increase when more heat is needed.  I'm
using eQuest 3.64.

 

Thanks for your help!

 

Rosie

 

 

Roselin Osser, BEMP, LEED AP

Building Science Corporation

30 Forest Street

Somerville, MA  02143

978-589-5100 x 5284

fax:  978-589-5103

 

Building Science Corporation
Somerville MA  |  Waterloo ON
 <http://www.buildingscience.com/> www.buildingscience.com

 

 

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