Hi everyone!
I'm modeling a building that does not have any cooling system in the majority of spaces (just in some office spaces). All occupiable spaces are heated and ventilated.
Knowing that these spaces in the Propose Building are not cooled, may I performe the energy simulation without cooling?(cooling only in small office spaces)
To model the baseline's building HVAC system (system 5), I've put the cooling setpoint very high so that the HVAC system does not consider any cooling loads when performing the sizing runs. Additionaly, in the simulation results I can see that there isnt't any energy consumption associated with cooling for these spaces.
I checked the unmet load hours for all buildings and everything checks ok!
Thanks all in advance!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
July 16, 2018 - 10:09 am
Do the spaces that are not cooled qualify for a heating only system #9 or #10?
Luis Andrade
3 thumbs up
July 16, 2018 - 10:45 am
I don't think so... My understanding is that HVAC systems #9 and #10 apply to "(..) storage rooms, stairwells, vestibules, electrical/mechanical rooms, and restrooms not exhausting or transfering air from mechanically cooled thermal zonesin the proposed design(...)". I'm reffering to spaces such as classrooms or study rooms, that do not have any kind of cooling equipments installed in the Proposed design.
The system chosen for theses (not cooled) spaces was system 5 and for those that are cooled, I chose system 3.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
July 16, 2018 - 3:16 pm
Technically you are suppose to also model a cooling system in the proposed and use the same temperature settings.
Luis Andrade
3 thumbs up
July 17, 2018 - 4:36 am
I agree. But if in the Proposed, in addition to the installed equipments (heating and ventilation) I add a system 5 for cooling only (no Heating nor outdoor air ventilating, with fan cycling on/off to satisfy cooling needs), the system would be sized with 0 kW cooling capacity and 0 kW fan power, since there is no cooling load due to the spaces' very high setpoint. Additionally, during the simulation, this system would never actually function, since the spaces' temperatures would never reach the cooling setpoint. Therefore, one may say that there is the same type of controls and settings for cooling in both proposed and baseline. They just don't function and its modeling in the Proposed would just be a waste of time.
I think this is a reasonable approach, since there are no cooling systems in the Proposed (just in those small offices). In both the proposed and baseline buildings there is only energy consumption associated with cooling in those small offices, where cooling equipments are actually installed.
Would you agree with these assumptions? If so, is there any documents/plants that the reviwers would like to see in order to confirm this approach and that there are no cooling systems installed for the majority of spaces?
Thanks in advance!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
July 17, 2018 - 10:44 am
I agree it is a waste of time for the reasons you cite. Since you know the work around associated with the requirement to model cooling systems, then you should explain that to the reviewer and you would probably not be required to model the cooling systems in either model. Demonstrate that there is no cooling installed in these areas and provide a narrative explanation for why you did not model a cooling system in either model in these areas.
Luis Andrade
3 thumbs up
July 17, 2018 - 1:26 pm
Thank you Marcus!