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

[Brian Fountain]

You need to change your zone thermostat action from Proportional to 
Reverse Action.

On 1/16/2011 9:24 PM, Roselin Osser wrote:
>
> 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
> www.buildingscience.com <http://www.buildingscience.com/>
>
>
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