Modeling in ASHRAE 90.1 2016

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Hi all,

This is my first project using ASHRAE 90.1 2016 and I'm finding some odd instructions in Appendix G.

A couple examples-

* Table G3.1 says that the baseline case is to use table G3.7 to define space by space LPD, but the proposed has to comply with section 9.1.3. There's a big difference between maximum allowed LPD between the two tables, for example G3.7 calls for open Office areas at 1.1 W/sf but table 9.6.1 says 0.81 W/sf.
* Baseline Wall insulation for climate zone 5b, per table G3.1 and G3.4-5 is to be simulated at a U value of 0.084. The proposed case must be under 0.055 per table 5.5-5.

Appendix G now has tables for envelope properties, equipment efficiencies and lighting power densities which all conflict with what we're used to finding in sections 5, 6 and 9 in previous iterations of the standard. Reading table G3.1 it seems clear that they want us to use the appendix G tables to define the baseline and not the tables in the main sections, but this makes no sense to me.

I feel like I'm taking crazy pills...can anyone shine some light on this?


Matt Garlick, CxA, CEM, BEMP
Building Efficiency Engineer | TBCx

E-mail: msg at
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Direct: 801-401-8456

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Hello Matt,

- ASHRAE 90.1-2016, section G1.2.1 explicitly says that ' *The interior
lighting power shall not exceed the interior lighting power
allowance determined using either Tables G3.7 or G3.8 and the
methodology **described
in Sections 9.5.1 and 9.6.1'*. So it seems you need to refer G3.7 or G3.8
for LPD values and* Methodology* should be as per 9.5.1 and 9.6.1
- Table G3.1 5(a) says '*All components of the building envelope in the
proposed design shall be modeled as shown on architectural drawings or as
built for existing building envelopes*' with some exceptions but none
restricts proposed values.

I haven't used 90.1-2016 to a great extent but standard seems quite
straight forward with some changes in formatting (tables, references etc.)
compared to previous versions. I stand corrected if missed out anything

hope this is helpful.


On Wed, Oct 16, 2019 at 7:54 AM Matthew S. Garlick via Equest-users <


Javed Iqbal, LEED AP, CEA
Sr. Energy Analyst

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Hi Matt,

The baseline building components referenced in Appendix G of ASHRAE
90.1-2016 are equivalent to ASHRAE 90.1-2004 levels, which is why the
baseline wall assemblies and other components in the same appendix are much
worse than the ones in the numbered sections (these are the prescriptive
components for 2016). The reason for this is to avoid having to create
different versions of the baseline model each time a triennial of 90.1 is
released (which was the case up until now). The proposed design will always
be compared to the 2004 modeling baseline and the results will be adjusted
relative to the respective version of ASHRAE 90.1 using Building
Performance Factors (BPFs), Performance Cost Index (PCI), and other new
metrics. See 90.1-2016 for more info.

Kind regards,

On Wed, Oct 16, 2019 at 1:49 AM Javed Iqbal via Equest-users <

*Calvin Chu, MFBA, EIT*
Energy Modeler
646-780-5536 | cchu at

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New York, NY 10005

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