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Re: [EnergyPlus_Support] Mandating EnergyPlus: Is it the right tool for energy code compliance?



Very glad to hear that CA has decided that the use of old tools that are not being updated with time is not acceptable@! I wish Oregon (where I live) and the rest of the USA where as progressive.  I have felt that the modelers of the USA are stagnated by the requirements for them to use DOE2 programs. To hear that CA is now finally allowing modelers to use tools that are current is great, and even better that it is a requirement! 

I think E+ is the right tool for the job- I say this for the same reasons I chose E+ is my core modeling program.  

  1. It is the DOE2 code, with more 14 years of effort. (E+ used to be DOE2, Blast and TRNSYS, but was consolidated around 1999-2000) 
  2. DOE2 is not capable of many technologies and workarounds may not work as well as proper code. The code is locked and not open, so continued development is not possible. 
  3. E+ does not have to take a long time per run. For example if you made a model with minimal surfaces and used only simple box zone shapes like Energy Pro does, used 1 time step per hour, one shadow calculation per season, simple solar distribution, and conduction transfer function heat transfer ect then the runtime would not be different. Actually with such simplifications the runtime would most likely be less for E+. It is when you add more advanced calculations that runtime is slower. The thing is if DOE2 based programs can not do the detailed calculations, but E+ can at a runtime penalty, or that E+ can have fast runtime without the detailed calculations then I think the penalty goes to DOE2. 
  4. The program when coupled with a UI such as Design builder (or my web based UI soon to be released) is really quite easy to setup and run. For example last week I did three models.  Advanced parametric and optimization routines are much easier in E+ then DOE2, TRNSYS, ESP-r, IES, IDA or any other program I have used. 
At that design meeting I suggest you to determine the full set of parameters that you would later model, then run through them later and make a report that you share with the team. This way you have the time to run through all of the combinations of options and can fully review the tradeoffs for the different options.  Also with a UI such as design builder you could still run the model at such a meeting. 

Possibly you should also post this to the BldSim list- so Nick can read and possibly reply..


Kind regards 




â??â??
Jeremiah D. Crossett  | Senior Analyst  | LEED Green Associate 
â??â??
120 E. Pritchard St.  | Asheboro, NC 27203 
â??â??
 | Mobile 503-688-8951
  





On Sun, Aug 17, 2014 at 9:29 PM, energycode_2013@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
 

Good evening from sunny CA. I am new to the forum and freely admit to being in over my head but have taken encouragement from reading through the past few years of posts and seeing newbies become active contributors, especially the repsonse from Nick Caton to Jeremiah Crosset in May of 2012...I forwarded the exchange to everyone in my office... we get few pearls of wisdom freely handed out. So..thanks!

To my question -

On July 1, 2014, California mandated that EnergyPlus be used for our state's energy code (Title 24) compliance. The switch was flipped and we are no longer allowed to use the DOE-2 program most of us had been using (EnergyPro). I am doing as much research as I can but am realizing that perhaps my modeling days are over - and while I am not that old and I am computer literate; I don't know CAD, SketchUp or OpenStudio all that well..and that's OK by me . Modeling was just something I did to suppport my diagnostic testing habit. As I have scoured the internets for training, tips and what-not-to-do's I found this forum and hope that you can offer your opinion.

Is EnergyPlus the right tool for Statewide code compliance? I understand it's an awesome and powerful program, capable of modeling advanced technologies, but is it the right tool for the market? The market being contractors and developers who just want compliance? The run times have been over an hour at times and these aren't extremely complicated multifamily projects - I see horror stories on here about a 300 zone supermarket that took 12 hours to run. Another factor mucks it up as well -

  • CA now mandates an integrated design meeting. No problem we'v e been doing them for a while - but it normally involves me running numerous iterations while I am sitting at the big table with the design team. These are for above-code projects so accuracy in predicting the % over code is paramount..absolutely paramount.  as often tax credits and incentives are on the line which means so is my job, backside and reputation if I get it wrong ( not saying the software I am using is accurate - but it's apples to apples) How do I explian to anyone that I've pressed calculate and now we must wait and wait? and........... by the way in CA we cannot yet model below-grade walls or solar thermal, chilled beams or VRF etc, etc (CA has a twist to the E+ interface called CBECC-COM to meet our code and the software code has yet to be written for these things) From the help desk: There is no formally approved workflow for modeling VRF systems in CBECC-Com. We are currently pursuing additional funding that will enable us to include these systems in a future version of CBECC-Com.
So... I am asking the professionals: is EnergyPlus the right tool for the job? or should I be justifiably peeved that it feels like I've been forced to ditch my 60 Mbps connection for a 14k Dial-up modem?
Your help is greatly appreciated.
Tommy Young
CEO
CEPE, HERS I-II Consultant
2701 Cottage Way, Suite 9
Sacramento, CA 95825





â??â??
Jeremiah D. Crossett  | Senior Analyst  | LEED Green Associate 
â??â??
120 E. Pritchard St.  | Asheboro, NC 27203 
â??â??
 | Mobile 503-688-8951
  





On Sun, Aug 17, 2014 at 9:29 PM, energycode_2013@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
 

Good evening from sunny CA. I am new to the forum and freely admit to being in over my head but have taken encouragement from reading through the past few years of posts and seeing newbies become active contributors, especially the repsonse from Nick Caton to Jeremiah Crosset in May of 2012...I forwarded the exchange to everyone in my office... we get few pearls of wisdom freely handed out. So..thanks!

To my question -

On July 1, 2014, California mandated that EnergyPlus be used for our state's energy code (Title 24) compliance. The switch was flipped and we are no longer allowed to use the DOE-2 program most of us had been using (EnergyPro). I am doing as much research as I can but am realizing that perhaps my modeling days are over - and while I am not that old and I am computer literate; I don't know CAD, SketchUp or OpenStudio all that well..and that's OK by me . Modeling was just something I did to suppport my diagnostic testing habit. As I have scoured the internets for training, tips and what-not-to-do's I found this forum and hope that you can offer your opinion.

Is EnergyPlus the right tool for Statewide code compliance? I understand it's an awesome and powerful program, capable of modeling advanced technologies, but is it the right tool for the market? The market being contractors and developers who just want compliance? The run times have been over an hour at times and these aren't extremely complicated multifamily projects - I see horror stories on here about a 300 zone supermarket that took 12 hours to run. Another factor mucks it up as well -

  • CA now mandates an integrated design meeting. No problem we'v e been doing them for a while - but it normally involves me running numerous iterations while I am sitting at the big table with the design team. These are for above-code projects so accuracy in predicting the % over code is paramount..absolutely paramount.  as often tax credits and incentives are on the line which means so is my job, backside and reputation if I get it wrong ( not saying the software I am using is accurate - but it's apples to apples) How do I explian to anyone that I've pressed calculate and now we must wait and wait? and........... by the way in CA we cannot yet model below-grade walls or solar thermal, chilled beams or VRF etc, etc (CA has a twist to the E+ interface called CBECC-COM to meet our code and the software code has yet to be written for these things) From the help desk: There is no formally approved workflow for modeling VRF systems in CBECC-Com. We are currently pursuing additional funding that will enable us to include these systems in a future version of CBECC-Com.
So... I am asking the professionals: is EnergyPlus the right tool for the job? or should I be justifiably peeved that it feels like I've been forced to ditch my 60 Mbps connection for a 14k Dial-up modem?
Your help is greatly appreciated.
Tommy Young
CEO
CEPE, HERS I-II Consultant
2701 Cottage Way, Suite 9
Sacramento, CA 95825




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Posted by: Jeremiah Crossett <jcrossett@xxxxxxxxxxxxxxx>


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