has anyone received a comment on eac1 requiring the use of residential
ptac systems in the baseline building when modeling fire stations? i
have seen the following comments on two fire station projects recently
with no further background material concerning the source of the
residential determination from the reviewers than the statements below.
this, to me, is not what previous usgbc cirs, 90.1 (2004 or 2007), or
the 90.1 user's manual say. per 90.1 and the previous usgbc cirs the
predominant use of the building, based on sf and number of stories,
determine what type of systems are used. for a building less than
20,000 sf this is typically going to be packaged gas or heat pump units.

project 1 (leed v2.2 project)
"The Baseline system type modeled does not seem consistent with the
system mapping from Table G.3.1.1.A. Please note the GBCI has determined
that Fire Stations are considered residential for the purposes of
completing EAc1 credit. Please confirm that the Baseline system (and
principle heating source) was modeled correctly, or revise the system
type to reflect ASHRAE modeling protocol. Also, if any exceptions are
utilized from G3.1.1 please provide a explanation for the exception."

project 2 (leed v2.2 project)
"5. Table 1.4 indicates the Baseline Primary HVAC system as a type #3,
which does not appear to be consistent with the system mapping from
Table G.3.1.1.A. The sleeping quarters (residential) should be modeled
as a system type #1 and the non-residential areas as a type #3. Please
provide a narrative confirming that the Baseline model sleeping quarters
have been modeled using System #1, Constant Volume PTAC, with DX
cooling, and Fossil Fuel boiler. The narrative shall also include size
of equipment modeled within the Baseline model. Revise Baseline Unitary
Equipment Cooling and Boiler parameters to match Tables 6.8.1A and
6.8.1E of ASHRAE 90.1-2004 and include Proposed Unitary Equipment
Cooling and size of the boilers. Please revise the Baseline and Proposed
models, and update the Template, and supporting documentation as
required. Please confirm that the parameters defined in section G3.1.3.2
through G3.1.2.5 have been modeled, and that the mandatory requirements
of Section 6.4 have been adhered to. Please add sufficient information
to Table 1.4 to confirm that the Baseline boiler systems were modeled in
accordance with these requirements"

the usgbc cir & 90.1 references:

1. USGBC Advanced Energy Modeling for LEED (page 17) - Table 2.2, CIR
dated 8/26/2008 and 4/23/2008. "Clarifies how to determine baseline HVAC
system(s) for building eligible for more than one system type."
-"CIR dated 8/26/2008 states that for projects with multiple uses in the
same building, predominant condition as determined by total floor area
should determine system type for entire building. Ruling references
note following Table G3.1.1A in ASHRAE 90.1-2004: Where attributes make
a building eligible for more than one baseline system type, use the
predominant condition to determine the system type for the entire building."
-"CIR dated 4/23/2008 confirms that when conditions do not vary per
exceptions to G3.1.1, project teams must use single baseline system type
for entire building. HOwever, if project includes multiple detached
buildings, each building can use different system type; this is
addressed in Chapter 4 of document."

2. 90.1-2004 Table G3.1.1A Note 3 - "Where attributes make a building
eligible for more than one baseline system type, use the predominant
condition to determine the system type for the entire building."

3. 90.1-2004 Section G3.1.1 Exception (a) - "Use additional system
type(s) for non-predominant conditions (i.e. residential/nonresidential
or heating source) if those conditions apply to more than 20,000 sf of
conditioned floor area." (Note the fire stations in the two projects
with the comments above are each less than 14,000 sf of conditioned
floor area.)

4. 90.1-2004 User's Manual - "The scope of Standard 90.1, in terms of
residential spaces, applies just to spaces with four or more stories, so
low-rise residential is excluded."

regards,
patrick