Hi Folks.
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I recently?start to use?Energypro to model the VRF system. In order to fully understand Energypro, I created?a single zone building served by PSZ DX system in eQUEST and Energypro.?All parameters such as location, design days, U factors,?wall?areas and Shading coefficients are all the same?in?both models. However, I found the?conduction through window, wall, roof and underground floor?and window solar gain are all different in LS-C report. Even I exported all DOE reports and compared them side by side, I still didn't figure out what the problem is. Hopefully some experts on this board can answer my question. Your feedback is highly appreciated.
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Best,
?
Shaojie??
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eQUEST vs. Energypro
Apr 22, 2009
Eric:
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EnergyPro is based on DOE-2.1E. eQuest is based on DOE-2.2. I am unsure of what actually changed between the two programs. But if you ever ran DOS based DOE-2, you would find differences between the A through E versions as well.
?
You were expecting a perfect world ??
I also use both eQuest and EnergyPro and have found that the biggest
(envelope) difference is that eQuest uses a "time value" (via thickness
of most materials), whereas EnergyPro has preset assemblies that you
choose from, none of which have multiple thermal components, just an
R/U-Value. I assume this is why you are experiencing this difference.
Matthew Higgins, LEED AP + ASHRAE-HBDP
I have asked questions about ASHRAE 62.1 on this list before, and I got
some good guidance. I am going to try again to see if anybody has any
ideas about my current dilemma.
I am analyzing a circa 1999 dual duct VAV building with ASHRAE 62.1:
2007. I realize that the building was not, and may not, meet ASHRAE
62.1:2007 requirements, but LEED Existing Buildings wants me to check.
Doing the analysis using the 62.1 spreadsheet, I can get it to pass but
only if I increase the minimum cooling airflow to some conference rooms
to 100% of design. This basically makes the VAV system into a constant
flow system in those rooms, and could over cool the conference rooms if
they are unoccupied and the lights are off, but it could be OK if the
rooms are full of people and in use.
It occurs to me that a CO2 sensor (demand control ventilation) could be
applied to such an instance, or possibly some sort of "occupancy
control", but I cannot find any discussion of such controls in 62.1.
Question: Has anyone had a similar problem getting an existing building
to comply with ASHRAE 62.1? Does anybody have a suggested solution?
NOTE: I am using 62.1: 2007 by my own choice. If this is a bad choice,
and I should be using 62.1: 2004 instead, please let me know.
Thanks in advance for any thoughts you might be able to offer.
--
Robert P. Wichert, P.Eng.
Found it!
ASHRAE 62.1: 2007 Section 6.2.7 "Dynamic Reset" seems to indicate that
CO2 control is just fine. If anybody has any advice on that, I'd love
to hear it.
Cheers!
Robert P. Wichert, P.Eng.