[Equest-users] Heat recovery chillers

[John T. Forester]

Charles,

Check the design temperature and delta T of the loop to which you are trying to recover the energy.  If the return water temperature is higher than the available energy from the chiller, no energy will be recovered.  I’ve modeled this process for pool heating (much lower supply temperature) and the results were reasonable.  Also check the maximum recover temperature on the Loop Attachments tab of the chiller.  By default it is set to 105°F.  I believe the highest is 120°F.  Search the help for MAX-RECOVER-T for more information.  This is also where you will want to define and attach a heat recovery pump if you have one.  That way it will cycle on and off when the system can/can’t recover heat.

Also try to put the hot water loop on a reset schedule (as long as it is in line with the design).  The lower the return water temperature, higher energy recovery availability.

If all else fails, run an hourly report that shows chiller state (on/off), recovered heat and loop temperatures to begin troubleshooting.

John


John T. Forester, P.E., LEED AP, Mechanical Design Engineer I BVH Integrated Services I 617.658.9008 tel I 617.244.3753 fax I One Gateway Center Suite 506, Newton MA 02458 I www.bvhis.com<http://www.bvhis.com> I Hartford ● New Haven ● Boston

From: equest-users-bounces at lists.onebuilding.org<mailto:equest-users-bounces at lists.onebuilding.org> [mailto:equest-users-bounces at lists.onebuilding.org]<mailto:[mailto:equest-users-bounces at lists.onebuilding.org]> On Behalf Of Charles Land
Sent: Tuesday, January 11, 2011 11:27 AM
To: equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>
Subject: [Equest-users] Heat recovery chillers

Has any one used the heat recovery option for an air cooled chiller?  I am trying to reject heat to the heating hot water loop.  Ive set this up as the heat receptacle.  It appears to be working but the savings are unrealistically small. Only 6 therms a year.

Charles (Jason) Land
Project Engineer
Geo-Marine, Inc | Energy Services Group
146 Market Place Boulevard | Knoxville, TN  37922
Office: (865) 692-0084 | Fax: (865) 692-0560

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