Mike06's profile - activity

@ Annie: thank you. the idea is good. But the temperature in the zone will change every hour, so that I would have to ca

thank you for quick answert. as far a I understood the humidistat in IdealAirLoads can only be of the relative humidity

How to model dehumidification load in naturally ventilated zone? My interest is in how much dehumidification load I woul

Great, exactly what I was looking for. thx.

I have been looking around quite a while, but did not find a particular documentation.

In EnergyPlus what is the output (e.g. mean zone air temperature or humidity ratio or relative humidity) at 01.01.2002 06:00:00?

1. the current value at 6:00:00

2. the average value from 5:01:00 to 6:00:00

3. the average value from 6:00:00 to 6:59:00

4. the average value from 5:30:00 to 6:30:00

I would assume it is option 2 according to the weather file format definition. But I don't know.

But is there a documentation on it?

does e+ handle phasechange materials in all solution algorithms? perhaps you have to change the solution algorithm in the "simulation > advanced > heat transfer function .... "?

thanks. I am already running a co-simulation with BCVTB (Ptolemy II), but wondered, if EnergyPlus would be able to write the hour of the day and the day itself as an output variable (which I then could use), instead of deriving it from the simulation time of the co-simulation. with mle+ I found out that it is not updated anymore and would not run with current MATLAB and EnergyPlus versions.

You could look at the "absolute" humidity and compare outdoors to indoors (it does not change with the temperature rise from outdoor to indoor). Use as an output humidity ratio of zone and of environment. Look at your internal humidity load: how many persons are there to provide moisture to the air?

If I want to perform code in the external programme (like MATLAB) during every time-step, depending on e.g. the time of the day, can I get that variable from EnergyPlus? Or do I have to derive that information from the overall simulation time (either in BCVTB or MATLAB)?

... and if it is possible like this, you could use a script to automatically write that code (use 1 loop for 44 else-if-statements, 1 loop for Hour, 1 loop for DayOfYear). Additionally generate the the 8760 Window definitions by a script automatically, too. But why would the U-value change randomly over time ... is that any practical approach?

Great, thank you! Now I know it is there, I found it in the documentation. But I think it should be Zone Air Humidity Ratio (without the Mean) ... at least according to the Input Output Reference ? documentation

I just found this: http://jess.ensims.com/epw_viewer.html

For historical data you can use https://www.wunderground.com/ Perhaps generate your own "averaged" data from it (e.g. 10 year average)?!

Have you heard about TRY (test reference years)? http://www.cibse.org/Knowledge/CIBSE-...

But those are not free, you have to purchase them.

Is there an option to output humidity ratio (g/kg or absolute humidity g/m3) of Zone from EnergyPlus simulation as output variable? Does anyone have experience with that? Or do I have to calculate those values from relative humidity?

I'm working on doing parameter studies with EnergyPlus and changing HAMT definitions. Which means I want to sweep through different adsorption isotherms etc. As it seems not possible to change them on the fly by the ExternalInterface Functionality, I plan to generate many different IDF files. Has anyone done similar simulations? I would like to exchange experience about that. And by the way: has anyone experienced an unusual difference in the thermal mass (heat storage) when switching from CTF e.g. to the HAMT solution algorithm?

In DesignBuilder 4.7 it was not possible to change the solution method to "HAMT" (Your were only able to change relevant parameters manually in the IDF file). But with the new DesignBuilder 5 Version HAMT is fully integrated.

Hello, I use Designbuilder and I have done all the HAMT settings for an individual material (indoor plaster) and chose "Include moisture transfer settings" for the material (and generated a new moisture transfer setting = "EMPD + HAMT"). For the advanced simulation method I can not choose EMPD or HAMT, but I allowed "individual constructions to override solution method". Now I have 2 different settings for a zone: first is with indoor plaster with low/bad sorption isotherms, second is with high/good sorption isotherms. After simulating I find no differences in the zone relative humidity at all. In the in.idf file I find no section with the sorption isotherms either. So I doubt, if E+ is really using the EMPD+HAMT solution algorithm.

Did anyone use EMPD/HAMT successfully in Designbuilder yet? Thank you and kind regards,

Thank you for your quick reply. I will try that and see how far I get ...

I would like to use Energy+ to model a moisture balance of 1 zone, including the moisture buffering and diffusion in the material. The HAMT-model should do it, but in OpenStudio I have not found a way yet to change "HeatBalanceAlgorithm" and to provide the additional parameters to a construction material. Can anyone help me?

Hello, I am interested in this topic, too. Do you know, if one can change the used HeatBalanceAlgorithm from "OpenStudio" (and provide the additionally needed material data). Or do I have to edti the IDF files manually?