[Equest-users] LEED Review Comment Help

[Karen Walkerman]

Basically, if the space is provided with heating, of a capacity greater than
15 btu/h-sq ft, then it is a conditioned space.  Appendix G requires that
all conditioned spaces be provided with heating and cooling for modeling
purposes.

In the past, when I have a building that is not occupied during the summer,
I have done the following:

In the proposed design model:

1.  model the heating plant as designed
2.  model a cooling system equal to the baseline cooling system

In the baseline model:

model the building with heating and cooling, determining the baseline system
following the usual method

IN BOTH MODELS:

create a thermostat schedule where, the cooling setpoint is set-back during
unoccupied hours.  Usually, I set the thermostat back to 90F +/-.  If your
building truly doesn't need cooling, the cooling plant will never come on.

--
Karen

2010/12/29 Travis Miller <tmiller at dcengineering.net>

> I have put together an eQuest model for a LEED project where there is no
> cooling installed for the proposed design. This spurred the following GBCI
> reviewer comment:
>
>
>
> *According to the primary HVAC system input and Table 1.4, no cooling has
> been provided for in the Baseline or Proposed buildings; However, cooling
> equipment should be modeled in both cases if the spaces are considered
> conditioned per the definition in Section 3 (page 13) of ASHRAE 90.1**‐**2004.
> Please refer to the definition of conditioned space, semi**‐**heated
> space, and unconditioned space in Section 3. If the heating output capacity
> is greater than or equal to 15 Btu/h**‐**sq. ft. then the space is
> considered conditioned so cooling should be included in the Baseline and
> Proposed Case models. The cooling should be modeled using the Baseline
> cooling system type (system type # 3)in both the Baseline and Proposed Case
> models, using identical cooling capacity ratios and efficiencies in the
> Baseline and Proposed Case. If the heating output capacity is less than 15
> Btu/h*sq. ft., then the space is considered semi**‐**heated or
> unconditioned, so only heating equipment should be included in the Proposed
> and Baseline models; the heating type, capacity ratios, fan volume, and fan
> power for these spaces should be modeled identically between the Baseline
> and Proposed Case. Please revise the Proposed model and Baseline model as
> needed so the correct system type is modeled in all spaces. Please also
> indicate the total heating capacity and building area for semi-conditioned
> spaces to verify that they qualify as semi-conditioned spaces. In addition,
> please update Table 1.2 and Table 1.4 as needed reflecting the changes.*
>
> * *
>
> I have read and re-read the ASHRAE section referenced with regards to the
> definitions of a space and what would make a building required to be modeled
> with cooling but I am not seeing what the reviewer is seeing. Any help or
> insight would be appreciated.
>
>
>
> A little background of the building: non-traditional school building with
> no summer use. Proposed design uses radiant floor heating. Climate zone 6B.
> Heating output for the different zones within the building is between 15-20
> Btu/h*sq.ft.
>
>
>
> I do not get into modeling very often, but I have found this forum to be an
> extremely valuable resource. Hopefully I will be able to contribute
> something for someone else in the future.
>
>
>
> Thanks
>
>
>
> Travis Miller
>
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