[Trace-users] How long it takes for energy modeling? HME

[Lui, Yury]

See below


Yury Lui, PE, LEED(r) AP, CEM
Senior Mechanical Engineer, Senior Associate



HP Critical Facilities Services, delivered by EYP MCF

200 West Adams Street | Suite 2750 | Chicago | IL 60606

312.846.8511 office | 312.846.8500 main | 312.846.8501 fax

ylui at hp.com<mailto:ylui at hp.com> | www.hp.com/go/eypmcf<http://www.hp.com/go/eypmcf>

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________________________________
From: trace-users-bounces at lists.onebuilding.org [mailto:trace-users-bounces at lists.onebuilding.org] On Behalf Of Sherie E. Hensley
Sent: Wednesday, April 01, 2009 12:47 PM
To: trace-users at lists.onebuilding.org
Subject: [Trace-users] How long it takes for energy modeling? HME


I have done several energy models over the last few years using Trane Trace.  I have heard others (typically from those who don't have experience with energy modeling) say "it only takes a day" to create an energy model and get results.

I am trying to get a better understanding of how long it takes others to complete an energy model.  I realize there are many factors involved and length of time can vary drastically given the complexity of the project.

For an xxx sq ft project with xxx systems:

1.  What phase are you starting the energy model - SD, DD, CD?

[YYL] If it's under my control, I would start at DD. But sometime I need to do it in late CD or early construction.

2.  What information are you starting with - load results from another program, rules of thumb for system sizing, etc?

3.  What program are you using?

[YYL] Trace or sometime eQuest

4.  How long does it take to build the proposed model?

5.  How long does it take to build the baseline model (per ASHRAE 90.1-2004, Appendix G)?

[YYL] It really depends on the type of the bldg. The more you can utilize room and floor multiplier, the quicker you are. However, some bldg type such as hospital, community center and data center has different parameters for all rooms, you really need to build the model space by space per LEED requirement. I quote 80 hours for the first run. The first 40 hrs includes a kick off meeting with the team and data collection. Then the second 40 hrs includes 2 day envelope and space by space setup, one day for system set up, one day for stimulation and one day for debug.

Another 40 hrs if I need to run second run to revise and update the modeling. Then another 40 hrs for misc items, including a second meeting to follow up the result, LEED documentation and response to USGBC review comment.

I would add more hours if I need to deal with architect and engineer who don't know much about energy modeling and need my hand holding to provide me the info. I would also add more hours if I start the modeling in earlier SD phase knowing there will be multiple minor update or revision of the project. You should also confirm whether you need to include PM, project set up, additional client face time or result reporting. Finally, be aware you could get more than 1 round of clarification request from USGBC's review. It's just from my experience, project with higher energy saving claim, the more detail info they tend to request.

6.  How long does it take to calculate the results from the energy simulation program?

[YYL] For the type and size of my project, 1 hr with 8760 hr weather data on my dual core 2.0GHz and 2 G RAM

7.  If you have started a projected in the SD phase, how detailed is the input information you use?  How do the results compare to the energy model developed in CD - within 10%?

[YYL] If that's the case, I would take advantage of eQuest's SD or DD wizard. 30 min for a block bldg analysis using all default value.



Any information you can provide would be helpful.

Thanks,

Sherie Hensley

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