[Equest-users] Would like to hear from you guys

[Hall, Brendan]

If you are a system 8 (Electric Heat), then the only pumps would be for chilled water. If your total cooling capacity is greater than 300 tons then the baseline must have variable speed drives. Even if you are less than 300 tons it is a primary/secondary loop with pumps riding their curves so it's less efficient but not straight constant volume. Also, with heat recovery it is important to look at how many hours you would expect that it would run in your climate. For example, you would not want to run a ERU when a economizer would be available. There are obliviously other ways to get to 10% but it can be hard with district systems because by not being able to take credit for having a chiller you are losing out on opportunity to gain efficiency. Good luck.

Brendan Hall

From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Yazan Abukhait
Sent: Wednesday, September 12, 2012 2:26 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Would like to hear from you guys

Dear all,

I'm involved in a LEED project where my company have hired a LEED consultant, among the buildings is an office building consisting of 6 stories, being fed from a central utility plant located within the project, the base line is the same that of the proposed building ( system 8) except that the VAV boxes are fan powered in the baseline. The mechanical engineer modeling the project is insisting that he can show a minimum of 10% energy savings by using variable speed pumps and AHUs and heat recovery, I believe the heat recovery part, but using variable speed pumps and fans should also being modeled for the baseline as well, isn't it the case? ASHRAE 90.1-2007 will not allow you to use constant speed pumps for pumps and fans even when you use the LEED supplemental document for district cooling plants treatment, would like to hear from you guys, and thanks in advance.

Regards
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