[Equest-users] High pumps equivalent full load hours in the model

[Chapin, Alex N]

Hi Morteza,

I looked at the file quickly and it seems that there are some changes that you can make to reduce the EFLHs slightly (I was able to get it to 8,146 hours/year by changing to two-way HW and CHW coils, moving cooling coils to secondary loop, readjusting pump flows and power after other changes, and setting loop operation to demand), but it seems like the underlying cause of the high EFLHs is probably due to having VAV systems which only serve interior spaces which are probably going to be in cooling mode year round.

Note that I think you can model the corridors on floors with residential as PTACs also. I believe that the reviewer should allow you to be flexible in how you define the corridor off of residential spaces. This might help reduce the pump EFLHs for primary and secondary chilled water pumps, assuming those VAVs which only serve core spaces are part of what is driving the high EFLHs.

Alex Chapin EIT, BEMP, LEED AP BD+C, O+M
Energy Engineer | Mason & Hanger
A Day & Zimmermann Company
D 804.521.7072 | O 804.285.4171 | F 804.217.8520
4880 Sadler Road, Suite 300 | Glen Allen, VA 23060
masonandhanger.com<http://www.masonandhanger.com/>
Building a More Secure World


From: Morteza Kasmai <morteza.kasmai at gmail.com>
Sent: Friday, January 18, 2019 1:29 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] High pumps equivalent full load hours in the model

Hello all,

I received following LEED review comment:

“The Baseline model pumps equivalent full load hours (determined by dividing the total annual pumps consumption (45,761 KWH) by the pump peak demand (5.426 KW) reflected in the simulation output report) is 8,433 hours/year, which is unexpectedly high given the anticipated schedule of operation for the project.”

This is a 9 story residential building with unfinished retail space in the ground floor. Primary HVAC system in the baseline case is PTAC and the secondary system that serves non-residential spaces is System 7 – VAV with reheat and chilled water. HVAC system in unfinished retail space of the propose model is System 7 as well. Pumps equivalent full load hours for the proposed model is 8,089 hours/year (15,401/1.905), which is close to EFLH of the baseline case.

Is this high EFLH loads relate to the primary and secondary pumps in both of the models and are justifiable or there is something wrong with the models. Attached are inp and pd2 files of the baseline model from version 3.65 build 7173.

Thank you for your help,

Morteza Kasmaei
Senior Architect
LEED AP BD+C, GGP






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