Hourly simulation without thermal history - analysis period

Hi all,

to evaluate the difference between an annual analysis in E+ with and without thermal history (warmup+sim) we tried to develop a way to overcome the LB-limits of the analysis period component (switching from h24 to h1). But still we can’t make it run.

Is there a way to achieve an animated one-by-one hour E+simulation with an alternative analysisPeriod-construction?

Thanks in advance,

Daniel

150722_HOURLY TIMESTEP.gh (434 KB)

Hi Daniel,

I’m not sure if I totally understand what are you trying to do. Warmup period is different from the analysis period and is critical for the accuracy of the results. Are you trying to set the warming up period to 0 days to see the effect on the results? If that is the case you should use Honeybee Simulation Control component.

See this discussion for an example:

http://www.grasshopper3d.com/group/ladybug/forum/topics/warming-up-…

Mostapha

I also am not sure what is the intention. But you can see the results hour by hour if you send an hourly timestep.

Is this what you want?

-A.

We want to compare A: the hourly results of an annual simulation from 1.1.1 to 31.12.24 (result=one-csv-file) to the B: hourly results simulated one by one from 1.1.1 to 31.12.24.

A: 1 warmup, results with thermal history

b: 8760 warmups, results without thermal history.

Tell me if it’s clear to you…

D

Daniel,

A: you can do with no problem. This is actually what i wrote before.

B: As far as i know (and i think i know), is not possible. But beyond that, doesn’t make sense for me. Anyway, in E+ you can set the starting day of the month and the end day of the month for the run period. In this sense you can simulate one day. If you do that with an hourly timestep you can get hour by hour of this day. So you can get 365 separated days.

The warming up can be set as Mostapha recommended in a different discussion (link above).

-A.

Daniel,

I believe that I understand what you are tying to do but you should be clearer about your terminology as I think this is the first time many of us are using the term ‘thermal history’ to refer to use of the previous hour’s E+ results instead of a warm-up period. Let me know if I am wrong with understanding this:

A: Just a normal annual simulation.

B: 8760 different simulations, each of which is only one hour long.

If this is true, you can easily run through all hour-long analysis periods (option B) with the following:

Just animate the slider. I attached a GH file with the components above.

-Chris

AnalysisPeriodForEachHr.gh (351 KB)

Hi Chris,

I have to disagree with your B answer. You can’t simulate an individual hour in E+.

As you can see, there is no option for lower resolution than daily.

But just to be sure, i tried your solution in attached one of the CSV results. You get the whole day … which includes the hours (of course).

-A.

house_v03.csv (103 KB)

Abraham,

Very good point and I should have checked before posting that reply. Daniel, if you use my file, you should animate the slider with only 365 steps and it seems the highest resolution you could run your thermal history experiment is on a day-by-day basis.

-Chris

Hi, thanks guys! It’s clear now to me. I’ll test some simulations and will see if there are still questions.

D

“Thermal History” in the meaning of surface temperatures of constuction (e.g.), a result of solar gain, zone temp. etc. And warmup period in the definition of energyplus. The thing is that I’m curious in using face changing materials (changing glass facade every hour), starting the simulation on an hourly basis, but finding a way to use the thermal history of the material chosen before. And, for curiosity, switching off the warmup days. And I came to the conclusion if I set the warmupdays to “0” with simControls, it ignores the input and writes the min and max values itself into *.idf (see attachment). There is no possibility in influencing it, right?

pics below