DavidFGG's profile - activity

I want to update an IDF file made on EP 7.0 to the latest IDF format for EP 9.6 in order to open the file in OS.

However, when i use the IDF Version Updater a got this warning.

When I go to the EP website and click the link to "Older Transition Programs" at the bottom of the download section, a warning that "License has expired" appears.

So, how can I update version 7.0 to 9.6?

Tnx ... found the solution with this post here.

EnergyPlus-Version Update from 7.0 to 9.6 I want to update an IDF file made on EP 7.0 to the latest IDF format for EP 9.

Contorling the zone thermostat with thermal comfort models I intend to model the required heating and cooling energy of

Jp, this explains it. I increased the infiltration rate, and the results changed drasticaly for the exterior zones, but not for the core zone.

OK, good to know :)

I am using OS to model an office building with EP. I have problems interpretating the results linked to the infiltration. I use the design flow rate method for infiltration. The design flow rate model is flow/exterior wall area. My building model is devided into 4 zones. One zone faces the south (TZ1) and one the north (TZ2) orientation, one represents the core (TZ3) and one represents the unconditioned shafts (see picture bellow).

In the Outdoor air summary results, the infiltraion rate for the core zone (TZ3) is zero, which is logical based on the design flow rate model (picture bellow)

The illogical part here is when in check the sensible heat gain summary. Here the infiltration heat addition and removal for the core zone is much larger then for the "exterior" zones.

Has anybody got an explanation for this?

OK, that is why the total site and net site energy are the same. Tnx

OK, i will answer and tag my questions appropriately from now on.

I am using ideal air loads in my model. When i changed the heating sizing factor and cooling sizing factor to 1.00, the results for heating and cooling energy did not change (End Uses).

Does this mean that no system energy losses are taken into account for the heating and cooling system when using ideal air loads ?

Because in the end results the total site and net site energy are equal (also total an net source energy).

Is it possible to somehow adjust the conditioned floor area in OpenStudio?

By default the conditioned floor area equals the total floor area.

I am modeling a building in Open Studio, and was thinking about shortening the timestep per hour in my simulation. The epw weather file consists of hourly weather data, the default timestep in OS is 6 per hour (10 min), and it seemed logical for me to reduce my time step to 1 per hour. The difference in the results was notable (0.35 % reduction for net site energy, 1.2 % reduction of heating energy and .0.9% increase in cooling energy), but not extreme. My surface heat balance algorithm was Conduction transer function and air heat balance algorithm was Analytical solution. My model runs on ideal air loads.

Can anybody explain to me why the number of timesteps matters, if the outside conditions stay the same for one hour?

Which heat balance algorithms are favourable for the surface and the air heat balance ? From what i read in the ergineering reference document, the analytical solution seems the most stable solution for the air heat balance, but for the surface heat balance algorithm, the options stay wider open.

When i tried importing constructions in the SketchUp plugin, nothing happened, but it worked in the OS GUI with the Load Library command. tnx for your help

Does this work also for constructions? Because when I try importing a construction nothing happens in my OS model (no new constructions in the inspector or in the OS GUI).

When i try to change the Ground outside bundary condition to OtherSideCoefficients (from now OSC) in OS GUI (Spaces:Surfaces:Outside boundary conditions), it won't let me. Then i tried to change the Ground surface into an OSC surface via the OS inspector in SketchUp and it worked, but it did not go through with the simulation, which is understandable because there is no option (or at least I did not find one) to enter the inputs needed for the OSC outside boundary condition.

OK, tnx anyway !

I am modeling a building in OS, for which the Ground and the Outdoors outside boundary conditions are not appropriate for al surfaces. That is why the OtherSideCoefficients boundary condition would come handy, but it looks like it is not possible to simulate a building with this option (simulating error) in OS.

Tnx.

OK, i checked the InputOutput reference, and now i have more understanding for the different outside boundary conditions. But still i have problems in OS. For my model the OtherSIdeCoefficients boundary condition is atractive, but it does not work in OS (simulation error). So i wonder, which outside boundary conditions in OS actualy work(it seems that only Ground and FCfactor method)?

Hello,

i am modeling a building in Sketchup using the OS plugin. I want to understand how to corectly model ground surfaces in OS, because you have more than one outside boundary condition option for ground surfaces. What is the difference if i use Ground or GroundFCfactorMethod as an outside boundary condition(or some other boundary condition for a ground surface)? Because it seems that in OS there is no difference, so what happens in EP?

Tnx,

David

Addition to question: Which outside boundary conditions relating to ground surfaces that are listed in OS are functional (it seems that only Ground and FCfactor method are operable in OS)?

I am searching for an advice or idea on how to model the shading devices on my model (office bulding). I would like to apply exterior blinds on my window. The problem is that in open studio the options for the control type are on/of/on if schedule allows/on if high solar on window. I would like a more optimised way of shading control to save cooling energy in summer and to maximise solar heat gain in winter, but at the same time keep the model as simple as possible.

In energy plus there are more options for the control types for shades, and i could go with the "on if high outdoor air temp and high solar on window".

What does it mean, when i model my object in Sketchup+OS and then edit the idf in EP launch (e.g. change the control type for shades)? Does this mean that i could view the results only from EP-launch, and that the changes in the idf would not reflect in the results from OS (and therby exclude any further analysis on my model using PAT).

I am new in EP and OS and just getting a good idea on how the two programs work and correlate with each other.

Hello,

i am modeling a multi-storey building which has different vertical shafts (elevator, ...) from the bottom to the top. Now i am wondering how should i model them. Should i make an one zone/space frome the bottom to the top, or should i divide the shafts into one storey units, with an appropriate (like air) thermal conductive floor.

Thanks for your answer/advice. David

Hello,

my model is a multistorey building, which has offices spread next to the envelope of the bulding and in the core (actually 2 cores) of the building it has a corridor arround other spaces (restroom, elevator shaft,...). To better understand the situation see the picture bellow.

Top wiew.JPG

So when i model the building core, i have to make a space inside a space. And here comes the problem, because the floor and the roof of the bigger space are extended across the whole surface of the bigger space, I get two floors and two roofs at the place of the smaller space. And in my case I have vertical shafts from the bottom to the top, which are divided by the roof and the floor of the biger space (see image bellow).

Section-Core.JPG

When i dellete the surfaces (which devide my shafts), they just come back the next time i open the model. Also i have problems with the boundary conditions. ( See imagees bellow).

Bundary coditions.JPG

Boundary conditions 2.JPG

Is it possible to make a space with a hollow core without the roof and the floor just overriding the hollow core? And if, can i put a smaller space in the hollow core of the bigger space?

David

p.s. Sorry for the long text, but i want to make my problem as clear as possible.