[Equest-users] Help - Modeling VRV-VRF System with eQuest

[Neil Bulger]

Hi Loi,

I have run across this as well with trying to model VRV in eQuest. PVVT is a difficult system to work with because it requires specifying 1 zone as the thermostat that drives the whole system. Therefore, 1 zone will drive what supply air temperature the central AHU delivers to each zone. This can make hours out of range on cooling difficult but, if heating is the issue you may have more flexibility with zone-level heating options (reheat or baseboards). However, that can start to look strange when in reality, these features do not exist. But, the hours out of range typically stem from this single-zone-thermostat issue with PVVT.

Another approach I have not perfected yet that I thought of was to try using the eQuest Water Heat Pump system. The Water Heat Pump ties to a WLHP water-loop (it appears yellow in the Water-Side tab). If you were to place a dry-cooling tower on this loop, effectively, the dry cooling tower would be (in my mind) the same as an air-source condenser, like we would see in reality with a VRV system (typically).

This may be good or bad on the airside in eQuest (I am hoping good) in that it provides another set of options and heat flow control at each system. Again, I have not dug into how this would go together best and I would imagine some post processing would be needed to understand the results.

Would love to hear any other creative ideas out there for VRV work-arounds.

Neil Bulger
Project Engineer
________________________________
I N T E G R A L
                          GROUP

427 13th Street, Oakland CA 94612
510 663 2070 x 235
nbulger at integralgroup.com<mailto:nbulger at integralgroup.com>
www.integralgroup.com<http://www.integralgroup.com/>
DEEP GREEN Engineering.
________________________________

From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Loi Ng
Sent: Thursday, January 12, 2012 9:38 AM
To: equest-users at onebuilding.org
Subject: [Equest-users] Help - Modeling VRV-VRF System with eQuest

Hi,

I am modeling VRV system based on a "Energy Trust of Oregon, Inc." guidance document (attached) posted by Mathew Larson of Colorado dated 12/12/2011.  The document recommends using a PVVT system to simulate a VRV system.  I used an air cooled PVVT system to model a VRV system.  However, the unmet hours on the heating is very high.  The cooling part is okay.  Does anyone has experience on bringing down the unmet hours?

Thanks!

Loi Ng
Mechanical Engineer, LEED(r) AP
Diversified Engineering, Inc.
914 Silver Spring Avenue, Suite 208
Silver Spring, MD 20190
Tel: 301-565-2000 x 234
Fax 301-495-1563

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20120112/ce17a215/attachment-0002.htm>