See all forum discussions about CS-v4 EAc2
 Subscribe to new posts about CS-v4 EAc2 Post a new question aboutCS-v4 EAc2
See LEEDuser’s guidance on CS-v4 EAc2»
FAQs about EAc2 :

The energy cost offset from onsite renewable energy cannot be used to demonstrate compliance with the prerequisite. Can this cost offset still be credited to the proposed energy cost savings for this credit?

View answers »

Forum discussion

CS-v4 EAc2:Optimize energy performance

Retail basline HVAC

Hi to all,

I am currently carrying out an energy model for a mall building and assigning the baseline HVAC systems to the zones. I am confused about the retail units, there are hundreds of them, and It sounds unrealistic to set a baseline HVAC for each of them. Is it acceptable to group them and sum all the areas and heat and cooling power to assign a baseline HVAC? have you done this before? do you have any recommendations?

According to section G3.1.1 Baseline HVAC system Type and Description

HVAC systems in the baseline building design shall be based on usage, number of floors, conditioned floor area, and heating source as specified in Table G3.1.1A and shall conform with the system descriptions in Table G3.1.1B. For systems 1, 2, 3, and 4, each thermal block shall be modeled with its own HVAC system. For systems 5, 6, 7, 8, 9, and 10 each floor shall be modeled with a separate HVAC system. Floors with identical thermal blocks can be grouped for modeling purposes.

Thanks

0
Post a reply

You rely on LEEDuser. Can we rely on you?

LEEDuser is supported by our premium members, not by advertisers.

Go premium for $15.95  »

Profile picture for user sheffer
Marcus Sheffer
LEED Fellow
7group / Energy Opportunities
LEEDuser Expert
4454 thumbs up

Mon, 04/03/2023 - 18:26

How is the proposed HVAC set up? What system is the baseline? You can certainly lump similar thermal blocks together as long as they have similar usage and loads.

Tue, 04/04/2023 - 07:10

In that case, can I lump all retail units since they have the same loads and usage? that is using one single HVAC system for several thermal blocks with the same loads and usage.  There is no propose HVAC for these spaces, it is not part of the landlord/design team scope. The baseline will be system 3 PSZ-AC according to ASHRAE 90.1. Thanks
Profile picture for user sheffer
Marcus Sheffer
LEED Fellow
7group / Energy Opportunities
LEEDuser Expert
4454 thumbs up

Tue, 04/04/2023 - 12:48

Maybe, it's hard to say for sure without seeing the project. The use of thermal blocks often becomes a judgement call. Basically the question is does lumping these spaces together in a thermal block have any thermodynamic implications? Will lumping these spaces together be a good representation of the thermodynamic properties of the project? If the implication are nominal then creating a thermal block is fine.

Add new comment

To post a comment, you need to register for a LEEDuser Basic membership (free) or login to your existing profile.