[Equest-users] No Heating from PVVT Heat Pump

[Bishop, Bill]

Eddie,
 
The first thing I would do is open a new project (or a copy of your
project) in the wizard. Select DX cooling, DX heating and Packaged VVT
Heat Pump for the system type. This will show you the eQUEST defaults
for this system type, which differ in several ways from your overrides,
giving you clues to improving the model performance. The help item on
the PVVT system type gives good information on how these are controlled.
-          Your ground level has floor surfaces that are exterior-type
instead of underground or interior/adiabatic, even for the spaces
located above the basement. Consider changing these to get more
reasonable envelope loads.
-          You have some zones with zonal exhaust met by balanced
infiltration. These zones are likely to have high unmet hours using a
single PVVT system per floor and the same thermostat schedules
throughout. Baseboards or reheat should help.
-          Your southern zones on each floor are listed first, making
them the control zones. Listing the northern-most zones first might
result in fewer unmet heating hours.
 
Regards,
Bill
 
William Bishop, PE, BEMP, LEED(r) AP | Pathfinder Engineers & Architects
LLP
Mechanical Engineer
 
134 South Fitzhugh Street
Rochester, NY 14608
T: (585) 325-6004 Ext. 114
F: (585) 325-6005
wbishop at pathfinder-ea.com
www.pathfinder-ea.com
P   Sustainability - the forest AND the trees. P
 
________________________________

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Eddie
Corwin
Sent: Wednesday, September 29, 2010 9:43 AM
To: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] No Heating from PVVT Heat Pump
 
So I determined why I was not getting any heating, and the resolutions
perplexes me.
 
 I am modeling an Air-to-Air heat pump, so in the air-side system -->
Basics tab I selected "NO" for the field "WL/GS Ht Pump".  In doing so,
I get no heating out of the system.  When I change the field to "YES"  I
now get heating.  Attached are two images showing the field i am
referring to, and showing that I have an air-cooled condenser.  Does
anyone know why this might be happening.  I am worried that eQuest is
treating my HP like a ground or water source HP instead of an air-to-air
system.  Any thoughts on the matter would be appreciated.  By the way, I
am using eQuest 3.64
 
-Eddie
 
 
________________________________

From: Eddie Corwin <ecorwin at altanova-energy.com>
To: equest-users at lists.onebuilding.org
Sent: Tue, September 28, 2010 5:17:21 PM
Subject: [Equest-users] No Heating from PVVT Heat Pump
I am trying to model a PVVT system, that uses an air-cooled heat pump
for heating and cooling.  For some reason, the system refuses to supply
any heating.  When I change the condenser type from air-cooled to
water-cooled, the system WILL provide heat.  Has anyone experienced
problems like this, or has someone successful modeled a PVVT air-cooled
heat pump?  I have attached my IDF and PD2 file for review.  
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