[Bldg-sim] equest load hours not met

Keith Swartz kswartz at ecw.org
Wed Dec 31 13:44:00 PST 2008


Peter,

Something else that can cause a lot of unmet load hours is too much of a nighttime setback. If it takes a long time for the system to warm-up or cool-down in the morning, that time can really add up.

Also check to make sure that the PTACs are allowed to "cycle at night." If the heating and cooling equipment is not allowed to run during unoccupied mode, that can cause a long morning warm-up or cool-down.

Another thing to check is the location of the thermostat for zones with different load characteristics. For example, a storage room next to an occupied room might be on the same temperature control zone, but if the thermostat is in the main room, the storage room may not get what it needs and have unmet load hours.

_____________________
Keith Swartz, P.E., LEED AP
Energy Engineer / Senior Project Manager
Energy Center of Wisconsin
455 Science Drive, Suite 200
Madison, WI 53711
Phone: 608.238.8276 x123
Fax: 608.238.0523
Email: kswartz at ecw.org<mailto:kswartz at ecw.org>
Web: www.ecw.org<http://www.ecw.org/>

Energy Center University
Your gateway to sustainable design training and online education programs.
www.ecw.org/university/<http://www.ecw.org/university/>
________________________________
From: Aulbach, John [mailto:jaulbach at nexant.com]
Sent: Tuesday, December 30, 2008 3:09 PM
To: Peter Lemessurier; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] equest load hours not met

Try making your thermostats reverse acting and increase the deadband between heating and cooling.

And send us the .INP and .PD2 if you would like us to review your inputs.

We are all professional here, so it is just an offer to help.

John R. Aulbach, PE, CEM
Project Manager
Nexant, Inc.
701 West Kimberly Ave., Suite 245
Placentia, CA 92870-6342 USA
Phone: 714-524-4402
Fax: 714-524-4407
email: jaulbach at nexant.com<mailto:jaulbach at nexant.com>


________________________________
From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Peter Lemessurier
Sent: Tuesday, December 30, 2008 1:02 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] equest load hours not met
I have a real nice equest model of a hotel that looks great, produces very believable annual energy profiles BUT has about 75% of zones listed as many thousands of unmet load hours, both cooling and heating.

We are using mostly PTACs with a few fan coil units (HW/DX).

Any obvious reasons why this many unmet load hours is happening?

Must be something simple but I am new to this program and cannot find it

Thanks in advance for any assistance!

Peter LeMessurier, P.E.
M/E/P Lead, LEED(tm) AP

Given and Associates, Inc.
735 S. Xenon Ct. #201
Lakewood, CO 80228
V: 303-716-1270 X24
F: 303-716-1272
C: 303-588-0071
www.givenandassociates.com

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