Test temperature tolerances for unmet load hours

July 28, 2020

Nikos Tsitsikas

LEEDuser Basic Member

2 thumbs up

July 28, 2020

Hi all,

I was wondering if I could pick someone's brains regarding the unmet hours test when running an energy model for ASHRAE 90.1 App. G compliance.

So far we have been sticking to the 2°F temperature difference, both for heating and cooling setpoints; however, would it be possible to go higher than that? Is there actually a limit we need to adhere to?

Thank you.

Kind regards,

Nikos

Post a reply

Marcus Sheffer

LEED Fellow
7group / Energy Opportunities

LEEDuser Expert

5909 thumbs up

July 28, 2020 - 1:53 pm

I don't think there are any specific space temperature setting requirements in 90.1.

Nikos Tsitsikas

LEEDuser Basic Member

2 thumbs up

August 3, 2020 - 4:44 am

Thanks very much for the reply Marcus.

So am I right to be thinking that we would be allowed to set the tolerance as high as we wish and have no unmet load hours in our models?

Nikos

Marcus Sheffer

LEED Fellow
7group / Energy Opportunities

LEEDuser Expert

5909 thumbs up

August 3, 2020 - 9:04 am

Let me make sure I understand. Expalin the temperature difference you mentioned. Is it the dead band? That should be at least 5 degrees F (Section 6.4.3.1.2).

Your temperature settings in the proposed model should reflect the temperature setting expected to be used in the building. The baseline should use the same settings.