Adjacent air temperature: choose room

[Sanne]

Dear all,

I am new to this forum. My name is Sanne and I am a student at the Eindhoven University of Technology. I'm currently working on my graduation project. For this project I am doing simulations with IES on a building which is a combination of a normal dwelling and a greenhouse.
I'm having problems with the formula used for a profile for the ventilation (opening of the windows) of the dwelling. I want to open the windows if the temperature inside the dwelling is higher than inside the greenhouse. So I chose room air temperature higher than adjacent room air temperature. But instead of using the attached greenhouse as an adjacent room, it is using the first floor (this is what the results are showing me). The formula looks like this: (ta_<ta). I tried typing the name of the room after the "_" and some other options but nothing works so far.

Can someone please tell me how to fix this problem?

Kind regards,
Sanne

[JosephG]

I never use "ta_" because I find it too vague. I always use ta(x), where "x" is a room index number [like, ta(15), where 15 is the index number of the room]. Tell IES exactly which room temperature you want. You can get more details on how to do this by going to the APPro help manual, page 35.

The only annoying thing about this method is that if the model is a work in progress and if rooms get added, the index number might change, which is a real problem when you have 500+ rooms. Other than that, it works great.

[Sanne]

Thank you JosephG, you really helped me!

I got one more question. The formula now defines when the window should be open. But for night ventilation I would like some kind of buffer in temperature.
So if I would want to open the windows for temperatures higher than 22 degrees Celcius and close them when the temperature has dropped to 18 degrees, what does the formula then look like?

Thanks in advance!

Kind regards,
Sanne

[JosephG]

Hi Sanne,

This is a big big limitation in Apache Profiles: you can't do what you just described. In order to do this, you need to be able to access data from a previous time step, which IES doesn't support. It's the only way to do what you described, and many people have wondered how to get it done. Apache HVAC does have access to that kind of data, but it can't be connected to MacroFlo to control the windows.

Sorry that I couldn't help you

[Sanne]

Thanks again JosephG At least now I know it isn't possible.