We are working on a project where the selected baseline HVAC system type is 8 with purchased chilled water only from a district cooling plant. The Minimum Performance Calculator states that it is required to model the Baseline HVAC system in this case with hot water boilers and not with electric resistance as the proposed design. We cannot find this requirement in ASHRAE 90.1-2010 Appendix G. Any Advise ?
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Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
May 9, 2018 - 9:54 am
I think you are right that it should not be a boiler in the baseline. Could you be more specific about where the MEPC indicates that you have to model a boiler in the baseline?
Amgad Khattab
Managing PartnerEngineering Solutions
May 9, 2018 - 11:22 am
It is required under HVAC General TAB. It says that based on the information entered in General Info TAB (We selected District Cooling Only) and based on Selected Baseline HVAC system Type (which is 8 in our case) under HVAC General TAB. Then we have to use hot water boilers in the Baseline and complete relevant data in the HVAC General TAB!!!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
May 9, 2018 - 1:25 pm
Ok now I see it. Appears to be a glitch in the MEPC (there have been many). What it is telling you is incorrect and actually makes no sense. The opposite is actually correct.
Amgad Khattab
Managing PartnerEngineering Solutions
May 10, 2018 - 4:07 am
Thanks Marcus
Amgad Khattab
Managing PartnerEngineering Solutions
May 13, 2018 - 4:53 am
Marcus,
Do the efficiency requirements for the chillers, cooling towers, pumps in ASHRAE 90.1 should apply also on the District Cooling Plant's equipment? We have no force on the DES Owner.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
May 14, 2018 - 11:32 am
The District Energy System guidance is contained within the Reference Guide. You use the actual plant values or it also provide potential default values.
Amgad Khattab
Managing PartnerEngineering Solutions
May 14, 2018 - 12:00 pm
I have all the technical selection of the the equipment inside DES but the efficiency of the Chiller (Kw/Ton) for example is not complying with the ASHRAE 90.1 requirements. Should the efficiency of the chiller inside the DES comply with ASHRAE 90.1 requirements?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
May 14, 2018 - 12:30 pm
The chiller within the DES does not have to meet the minimum efficiency requirements. It is set up in a way that will penalize a poorly performing plant.