[Equest-users] Difficulties applying eQuest 3.63 to achieve LEED EAc1

[Yogendra Shah]

Please see numbered list further down to skip to issues or read background
info below.

We are using eQuest to model a storage facility and stand-alone retail
office building for the storage. We have to follow LEED v2.2 requirements
which calls upon Ashrae 90.1-2004 that specifically dictates the
requirements for the baseline and proposed models. We are having problems
entering and incorporating some of these requirements into eQuest and it's
critical that we find a way to account for these requirements in order for
us to achieve LEED EAc1 credit. The buildings have been modeled and we have
preliminary results using EEM run measures that do not include certain
requirements, which would most likely have to be modeled and run using
parametric runs. If some of the requirements require to be modeled in the
detailed mode then the entire simulation must be done using paramtric runs,
which adds complexity as compared to the easy to run EEM measures using the
wizard. I am still in the process of learning parametric runs. Any help
provided would be much appreciated.

1. The LEED reference guide requires that baseline model be sized using
default ratios. I assume it refers to oversizing the HVAC cooling capacity
by 15% and heating by 25% according to "G3.1.2.2 Equipment Capacities" but I
am not sure where this information must be entered or specified. I suspect
it must be entered in the detailed mode and simulated using parametric runs.

2. The baseline model should have total fan power fixed based on total
supply air volume. There's a section in Ashrae 90.1 G3.1.2.9 that says
"Supply Fan Power. System fan electrical power for supply, return, exhaust,
and relief shall be calculated using the following formulas:
Pfan= 746 / ((1 - e^[-0.2437839 * ln(bhp) - 1.685541]) * bhp)
where,
Pfan = electric power to fan motor (watts)
bhp = brake hoursepower of baseline fan motor from Table G3.1.2.9, where cfm
represents design supply flow rate."

Table G3.1.2.9 has another formula for calculating baseline fan brake
horsepower for buildings with less than 20000 cfm or more than 20000. Our
building is under 20000 cfm so we select the corresponding formula and
obtain the bhp. I would then plug it in the formula above to obtain watts.
What would I do with this? Would I take the fan power in watts and divide by
our actual cfm for the building to obtain watts per cfm? Where should this
be plugged into eQuest? Any ideas? Also fan mode must be set to continuous
in the baseline and cycling in the proposed building and entered somewhere
in the detailed mode if parametric runs have to be used.

3. Economizer has to be set for baseline building, which is easily
accomplished thru the wizard but not certain about where in the detailed
mode for parametric runs. What kind of economizer should be used for
baseline? Options in the wizard include drybulb temperature, enthalpy and
dual enthalpy.

4. Other smaller concerns include roof reflectivity must be 0.3 for baseline
and 0.55 for proposed building which cannot be specified thru the wizard,
only selected from available roof colors, none of which corresponding to
those exact numbers. I would have to enter them in the detailed mode for
parametric runs.

Items 1 & 2 are of more concern since I don't know how to resolve them at
this point. I have some ideas about items 3 & 4, just haven't had a chance
to try them yet. Please let me know if you have any ideas or knowledge about
eQuest and energy modeling for LEED EAc1 certification requirements. In the
meantime I will continue to figure this out.

Thanks to everyone
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