General Questions

[Galazios]

Hallo,

I am currently a student in Aristotle University of THessaloniki (AUTH) and as a part of my thesis I am working on Ecotect Analysis in order to calculate the Thermal/Cooling Loads of a dwelling. So far I have come up to some difficulties and I would like your assistance in order to overcome them.

So let me start:

- I want to make a schedule for HVAC with two different operational timetables. More specifically, I would like to make a table from 00:00 - 7:00 with a Lower Band of Temperature at 16degrees and a second one from 14:00-23:00 with a Lower Band of Temperature at 20degrees. The reason I think is obvious, since during the night we do not need as high internal temperature as during the day. Is there a way to do so?

- Where can I see the total U-Value of the residence?

- While trying to make some adjustments in windows' material, I could not find anything with an objectively low U-value. What I mean; The best possible material is "DoubleGlazed_LowE_TimberFrame" with a U-Value of 2.260 W/m2K  which does not even have a thermal break. I tried to optimize it through the Layers-topic but could not come up to any combination with a U-Value of around 1.5.

- Is there a differentiation between vertical and horizontal structural components or they are both included under the term of "Walls" ?

Thank you for your time reading my post. Looking forward to your reply.

Regards,

Traianos Moutaftsis

[Pennetier1]

Hello Galazios, 

1. Regarding creating a schedule for your HVAC system, I understand what you are trying to do, but unfortunately, you cannot assign different thermostat ranges to a single thermal zone, so you would have to stick with a single temperature for your lower band.  Technically, you could write a script that would run the same calculations but adjust the thermostat range for particular hours of the day.

2. To estimate the total U-value of your building, switch the thermal calculations to "Hourly Temperature Profile", and select "All Visible Thermal Zones". You can see the Total Exposed Area (A) and Total Conductance (AU) of the building.  Dividing AU by A will give you the average U-value of the exposed surfaces.  There are no automatic "building U-value" option here.  Again, you could write a small script that could do that.

3. The default materials are just a starting point for your model.  As you know, you can adjust material layers to create your own assemblies, but that is not necessary.  You can simply create a new assembly and enter the U-value you want; that is what Ecotect will use. The reason you are having trouble creating your own glazing assembly using the layers is probably due to the Air Gap layer.  The best windows can use other gases, and most manufacturer listed U-values include the frame of the window, which is not available as an input in the layers; so for the windows, simply enter your desired value of 1.5 and save as a new material. 

4. No, there isn't any difference per se between horizontal and vertical elements, in that Ecotect will treat them the same way; however, for some import operations where Ecotect has to guess what element you are are importing from another CAD model, it will assume that vertical planes are walls, horizontal plane are ceilings/roofs, and if the vertical element is on the ground, it will be a floor.  You can make a wall assembly horizontal if you wish to do so, or a roof vertical.

I hope this helps a bit.

Let me know if you have more questions on this topic, otherwise please accept as a solution so that others can benefit from this information.

Cheers,

[Galazios]

Hello Mr. Pennetier,

Your reply indeed helped me a lot and covered my quiestions. The only thing left is that I do not know yet how to write a script and make the adjustations you told me about. I will search for it in "Help" bar so not to put you in trouble explaining it to me.

Thank you again for your help

Regards,

Traianos Moutaftsis

PS. As my thesis goes on, I will probably come up with some new questions. Hope you are willing to help me through them.

[Galazios]

Hello again,

Unfortunately, no matter how much I tried over the last week to find a way to do this on my own, I havent found anything effective. I am talking about the script problem with the two different operation timetables and I would really apreciate your analyzed help on how this script should look like. Thank you very much in advance.

Regards,

Traianos Moutaftsis

[Pennetier1 · Accepted solution]

Hello Traianos, 

I have written a script - see attached - that will get you in the right direction.

This script will calculate the HVAC loads for the current zone.  It will ask you two different lower thermostat temperatures: the first one for the first time period, the second one for the second time period.

The script is currently set to run for the month of January (day 1 to 31); for an annual calculation, change the range to 1, 365 at line 29.

To change the time of the day, you will have to edit the script at lines 38 and 45.

The script is pretty self explanatory.  

To run the script:

1. Change the *.txt extension to *.scr

2. Drop the script into your Ecotect canvas or open the Script Manager and run it from there.

Let me know if you have more questions on this topic, otherwise please accept as a solution so that others can benefit from this information.

Cheers,

[Galazios]

You really untied my hands Mr. Pennetier. The script is 100% understandable and it runs perfectly with the provided adjustments for LowerTemperature and time schedules.. One final question; is there a way to run it for All Thermal Zones at once instead of currentzone per time ? I know the calculations may take a while this way, but it will save me a lot of time from excell reports.

But still, thank you again very much for your help and your time spent. I hope my thesis continues without any other questions regarding Ecotect.

Regards,

Traianos Moutaftsis

[Pennetier1]

Hello Traianos, 

Let me look into this; I remember trying to set this for All Zones, but for some reasons, it would not work.

I can probably make the script go though all visible thermal zones.  It might go faster than doing this one at a time... maybe not.

I will let you know soon.

Cheers,

[Pennetier1 · Accepted solution]

Hello Traianos, 

See attached script.

It simply adds up the loads of all thermal zones in your model.

If you wish to ignore a particular zone, simply set it to "non-thermal".

I assumed the thermostat temperatures would be the same for all zones.

Obviously, you should be able to edit the script to your liking once you understand a bit what is going on in there.

I hope that helps.

Let me know if you have more questions on this topic, otherwise please accept as a solution so that others can benefit from this information.

Cheers,

[Galazios]

Yes, that is pretty much what I was thinking. 

Thank you very much for your help all this time!

Regards, 

Traianos Moutaftsis