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Re: [EnergyPlus_Support] Report for you to download: PNNL Published Appendix G Reference Manual





Thank you Bing and team. This kind of document is long overdue and will probably grow in future.

I'm reading through it as I get the chance and will comment.

The last line of the table in section 2.3.3 addresses the HVAC system modeling requirements of the baseline building for "unenclosed spaces" (these spaces my be conditioned and or ventilated in part or in whole or indirectly YET STILL not count as "conditioned space"!). Explicitly mentioned examples are Ventilated Parking Garages, Attics and Crawlspaces.

The last entry in the table says to model these spaces with the same mechanical system as they have in the proposed model. However, here we need some clarification...

For example, if my garage is hooked up to my DOAS in my proposed design and the proposed design has a fancoil to heat the space, then I need to do two things with the space in the baseline:
1) ventilate at the same rate
2) condition
To do this I could
a) define a new system of type DOAS with fancoil (i.e. same system as proposed model) and have the program autosize the capacities, YET keep the efficiencies of all devices such as the thermal wheel heat recovery device at 80% as in the proposed (even though for the much smaller system this is unrealistically high). It may be impossible to reconcile the heating fuel source required by the baseline model with that of this new system. For example, if the fancoil uses steam in its heating coil and the AHU uses water, but the baseline is a gas fired system.
b) define the terminal devices such as air inlets and zone equipment (decentralized devices) the same as the proposed model, but supply them with the existing baseline central equipment (reconciliation problems may still exist).

I'm for a).

But to be honest, I would prefer if the standard handle this with the exceptions of spaces having largely differing loads or schedules and using the normal rules to select a stand alone system as prescribed by the baseline system types. I don't like trying to model proposed HVAC systems in the baseline. It always leads to issues. The standard should focus on keeping these as separate as possible.

I would expand on the guidance here.

...more comments to come.

On 11 May 2016 10:19 pm, "Bing.Liu@xxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
 

Thank you everybody who are interested in reading this over 300 pages manual. The link to download the report works now.


http://www.pnnl.gov/main/publications/external/technical_reports/PNNL-25130.pdf 


If you have suggestions to change, please feel free to contact us at PNNL.


Background:


Pacific Northwest National Laboratory recently published a technical report titled ASHRAE 90.1-2010 Performance Rating Method Reference Manual. This work was funded through DOEâ??s Building Energy Codes Program.  The report is intended to be a reference manual for the Appendix G Performance Rating Method (PRM) of ASHRAE Standard 90.1-2010. The procedures and processes described in this manual are designed to provide consistency and accuracy by filling in gaps and providing additional details needed by users of the PRM. This document builds from existing reference manuals including the Nonresidential Alternative Compliance Method (NACM) and Commercial Energy Service Network (COMNET) and has undergone an extensive vetting and review process.

 

Potential users of this manual include energy modelers, software developers, and implementers of â??beyond codeâ?? energy programs. Energy modelers using ASHRAE Standard 90.1-2010 for beyond code programs can use this document as a reference manual for interpreting requirements of the PRM. Software developers of tools for automated creation of the baseline model can use this reference manual as a guideline for developing the rules for the baseline model.

 

Thanks,

Bing Liu


Bing Liu, P.E., CEM, LEED AP

Group Manager, Building Energy Regulatory Analysis

Program Manager, Building Energy Codes

Pacific Northwest National Laboratory

bing.liu@xxxxxxxx





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Posted by: Jean Marais <jeannieboef@xxxxxxxxx>


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