Hello all,
a little question about the definition of "conditioned space". I have some spaces wich are not occupied and unconditioned (for exemple storage or technical spaces): do i have to consider them conditioned spaces according to the definition in section 3 of ASHRAE 90.1, and consequently to simulate a cooling/heating system in both baseline and proposed building?
Thank you in advance!
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Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5921 thumbs up
October 2, 2012 - 9:34 am
Ciao Fabio,
Technically you are supposed to do so according to Table G3.1.1-10 Proposed (c&d). The work around is to set the temperatures in those spaces so that the systems never operate. Given the waste of time it would be to model a system that does not operate we do not include systems in these kinds of spaces.
FABIO VIERO
Head of SustainabilityManens S.p.A.
18 thumbs up
October 2, 2012 - 10:08 am
Ciao Marcus,
thanks for the reply.
I totally agree with you, but my question comes from a technical review for a certification.
In your opinion is it better to modify the simulation introducing these systems (and not to make them actually work) or simply justify as you have explained?
Thank you very much!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5921 thumbs up
October 2, 2012 - 10:50 am
We don't model non-existent systems if it is just small spaces within the building. The reviewer would likely not even notice and we would address the issue if asked and provide an explanation.
If we run into this situation in a large space where the lack of a system would get noticed, we would likely submit a narrative explanation for why we did not model a system (raising the points above).
So we would usually justify our position unless the reviewer sounded particularly insistent on including the systems and wasting our time.
Bottom line is which way takes more time - modeling the non-existent systems or writing a few sentences.
FABIO VIERO
Head of SustainabilityManens S.p.A.
18 thumbs up
October 2, 2012 - 12:03 pm
Clear and comprehensive as usual!
Thank you Marcus!
FABIO VIERO
Head of SustainabilityManens S.p.A.
18 thumbs up
October 24, 2012 - 9:19 am
Hi Marcus,
do you think that this narrative could be appropriate?
" We confirm that there are 268.195 square feet of unconditioned area as per the definition in Section 3 of Asharae 90.1-2007. These areas are technical risers, lift risers and storage that do not require any temperature control or outside air according to Italian Regulation".
Thank you very much!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5921 thumbs up
October 24, 2012 - 10:21 am
One suggestion is related to the term risers. We use the term riser to refer to the MEP content like an electrical riser diagram. When referring to the spaces or areas within which those materials are housed we call that a shaft. I am guessing you mean shafts which are the openings the MEP stuff goes into like the elevator shafts and the duct shafts.
Is that 268 thousand square feet? If so that is a pretty big area. The fact that Italian regulation does not require conditioning this unconditioned space is probably not relevant beyond the fact that that is why it was not included in the proposed design.
The justification for not modeling heating and cooling in these spaces is that Appendix G only requires heating/cooling for conditioned spaces (see Table G3.1-1 Proposed (b) (you could cite this in your narrative). So I may have somewhat mislead you originally. If they are truly unconditioned then you do not need to model heating/cooling at all. You might want to explain the storage space a bit so the reviewer understands why it does not require any conditioning.