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Re: [EnergyPlus_Support] Re: I need your help





I am a self taught Energy Modeler, applaud you for taking such a large project as your first and think that it is possible for you to accomplish the task (so long as there is not anything to different about the project than the norm, and you are able to get good data to work with) , but also agree for the most part with the comments posted by others on the list.
I think I saw a separate post from you saying that you plan to submit to the USGBC in March. 

My opinion is as follows:
If you had a world class team you would not be submitting by March. Many LEED projects stretch on for over 1 year. 
You should check if there is any real reson to submit in March, as this is your first large project and you may not wish to rush. 

If you are working with a good team of architects and engineers you should be able to get good starter data for your proposed building, then build your baseline from there. If I where you I would make it very clear that you are in a design development stage until the designers of the building have provided you with everything you need. ((do not fall into the common trap of allowing yourself to have to design the building as that is not the energy modelers job)) You may wish to use Design Builder or possibly ACOSIM to build out as much of your project as possible. By using design builder free for a month you can create your working Energy Plus model that can be then edited in the Energy Plus IDF editor, or in Open studio/sketchup.. (I find it much more intuitive then open studio, even tho I like the idea of open studio better ) Ask the design team to provide you with GBXML or 3D CAD files rather then starting from scratch. For zoning I advise using thermal blocks rather then actual rooms, and the area average lighting method as to simplify the process a bit. 
You could take the project as far as possible, then summarize the issues you have and post to this list, and the help desk then fix everything you can.  Then document your inputs and issues very well and bring in a consultant who can assist you in solving the final issues prior to final submission to USGBC, then when they inevitably find some issues that you will be required to solve (4 months later) bring back in the same consultant to help with the re-submit. 

First I advise you to take this short online class, as it is cheep and the best I have found for cutting to the chase on how to approach energy modeling for LEED.
Hope this was helpful, and go Underdog!! You can do it.


On Sun, Feb 19, 2012 at 12:32 PM, Jim Dirkes <jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
 

Very well said by both Marcus and Jean.

If this project is one for which you or your company have responsibility to the Owner or investors (not, for example, a thesis), you should stop now and find an experienced energy modeling partner company.

If you or your company have estimated the cost to prepare the energy model with no previous experience, you should carefully examine your risk (as Marcus suggests) to determine the impact if it takes you 5 times longer than you estimated in both people-hours and calendar days. With my early experience using EnergyPlus that was my story.  Fortunately, my client was flexible and understanding! (and my bank account was not depleted completely).

 

The Building Performance Team
James V. Dirkes II, P.E., BEMP , LEED AP
1631 Acacia Drive NW
Grand Rapids, MI 49504
616 450 8653

 

From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of Jean marais
Sent: Sunday, February 19, 2012 9:51 AM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: [EnergyPlus_Support] Re: I need your help

 

 

Modelling is all about assumptions and simplifications.
How big or small the task is depends on this.

What is being asked of the model? Is it to investigate exsisting alternitives of envelope and geometry only? Is it supposed to predict energy usage "as built" on a hourly basis with kW accuracy of real life? Or is it something in between. If the client expects high accuracy and granularity and the performance of each individual system, tell them that they can't afford it. It would take an expert team several months to finish the model and is no task for one bigginer by himself.

I've been working in many roles on the new airport in Berlin. In my company it has taken two people 3 months to model and simmulate the design heating and cooling demands as per the German norms. Just the loads are simmulatet at ideal conditions.

It took me 2 months to simulate a very simplified geometry of the airport dynamically using a roughly equivallent AHU with an evaporitive cooler in the exhaust before the thermal wheel heat exchanger coupled to a VAV system with CO2 demand ventilation, chilled ceilings and floors and fancoils, using Design Builder and e+ just for the dynamic reaction and control for only the design cooling day. These building are complex in the number of systems not the physical size. Yes, exhaust fans (fatty air exhaust) and kitchen modelling is important.

Like Marcus said, protect yourself contractually, as the big building companies are political and rutheless. People don't realize how huge these things are. I'm currently simulating the air and water hydrolics to find the regulation setpoints on valves and regulators. The results table of one of my ceiling loops was over 300 pages, and there are about 100 loops to do. We are using expensive softwares with special interfaces to use existing 3D hvac geometry to expediate things and still it takes ages.

Even worse is that plan changes are still comming in.

Good luck.

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Mário <mneves32@...> wrote:
>
> Hello Everyone,
> I need to run a lot of simulations. To do this in a realistic time I need to automatically run E+ using code automation. Is there any documentation on how to do this?
> Thank You
> MN
>

As an HVAC engineer

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "syrianboy2002" <syrianboy4ever@...> wrote:
>
>
> First of all I want to explain my BIG project that needs to be modelled.
>
> Information:
>
> -The total building area exceeds 500,000 sq.mt (GF+1st+2nd+3rd+B2+B1)
> floors (Airport in Kuwait)(15 MAP)
>
> -Central Plan consists of (18 parrallel chillers, CHWP(9 primary, 11
> secondary + 9 condenser water pumps), 18 cooling towers) District
> Cooling only.
>
> -More than +180 AHUS (100% FAHU , AHUs for Displacement Ventilation, VAV
> AHUs, CAV AHUs (for substation) ).
>
> My questions:
>
> E+ is new for me, I have done all exercises in the getting started. I'm
> aware of most of the classes and objects.
>
> -Can you guide me on the process of taking this project forward in E+?
>
> -Do I have to model all of the equipment mentioned up, in addition to
> other Exhause Fans, Smoke Fans..etc?
>
> I mean you can imagine the project how big it is.
>
> My Available Data:
>
> -I have the 3d model of the project in googlesketchup(openstudio) (I'm
> aware of using this tool).
>
> -I have completed till the "Schedules Class" in the .IDF file.
>
> Recommendations:
>
> -I prefer to work on the 3d model in googlesketchup, since the profile
> of the building is complicated (your advice is still appreciated).
>
> Best Regards,
>
> Ameen Mattar
>
> Mechanical Engineer
>




--
Jeremiah D. Crossett
CleanTech Analytics
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www.cleantechanalytics.com


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