Hi,
for the unmet load hours test there is a throttling range to be defined. As I understand from ASHRAE 90.1 there is no fixed value for this range, how shuold it be defined? Is it linked to any other setting of the system? Which could be standard/accepted values?
thank you
Christopher Schaffner
CEO & FounderThe Green Engineer
LEEDuser Expert
962 thumbs up
April 6, 2011 - 2:59 pm
You are correct that there is no fixed value in 90.1. Only requirement is that it is identical in both Baseline and Proposed cases.
Many modeling programs use 2 deg F as a default - that is usually where I start. I'll only adjust it if I see funny results such as high of unmet load hours, or big reheat loads.
Elisabetta Annoni
Building engineer11 thumbs up
April 7, 2011 - 2:16 am
Thanks for your reply and advice.
SIG - Sustainability Main Account
Sustainability ConsultantsSustainable Investment Group (SIG)
86 thumbs up
November 3, 2020 - 1:24 pm
Would increasing the throttling range then be acceptable to resolve UMLH in both the proposed and baseline models?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
November 3, 2020 - 2:01 pm
Possibly. The settings must be idential in both models and should represent reasonable values based on the likely occupancy. Procedures for reducing UMLH are contained in Section G3.1.2.2.