Hi All!
I am working on a project where the cooling supply air temperature needs to change for every timestep while the simulations are running. When I make a list and insert it into the air details component, it creates multiple zones instead of assigning multiple temperatures for one zone. Is there a way to assign multiple supply air temperature for one zone?
Furthermore, I would like the fan efficiency to be a variable of the indoor temperature from the previous timestep. So, for example, if the temperature during the last timestep is 20C, the efficiency is 0.5. Is there a way to do this?
It sounds like you need something beyond what the ideal air system gives you. For one, the Ideal Air System (as the name suggests) is ideal and not representative of any real HVAC system. It has no fan object in it and no fan efficiency. So I recommend that you start from one of the other Honeybee HVAC templates that closely resembles the real HVAC system you are trying to model (almost all of the others have some type of fan).
I would like the fan efficiency to be a variable of the indoor temperature from the previous timestep
Changing the fan efficiency at in relation to other variables is usually done with a “Fan Curve,” though I think the other variable is usually the fan flow rate and not the supply temperature (not sure if what you’re suggesting here with supply temperature is possible in E+ without having to use the EMS). In any case, Fan Curves aren’t exposed on the basic honeybee components and you will either have to edit the curve in OpenStudio Application GUI (and then rerun it from Grasshopper) or build a HVAC system with Ironbug, which has components to set the fan curves.
the cooling supply air temperature needs to change for every timestep while the simulations are running
Again, the ideal air system doesn’t support the ability to change this but, for most other detailed HVAC systems, you can change the supply temperature from one timestep to another by editing the schedule of the setpoint manager in the air loop using either Ironbug or the OpenStudio GUI like so:
Hi Chris
Thank you for your answer.
I have looked at both methods, and I will try to use Ironbug.
I did, however, noticed that many of the Ironbug components do not have any descriptions. Is this because I have an older version of Ironbug?
I have now tried to create a VVT system (variable volume and temperature) out of the Ironbug VAV system. I do, however, still run into a few problems.
I want to make a temperature schedule with a different temperature for each hour around the year, but it seems like it is only possible to make a schedule for one day. Is there a way to make a schedule for the entire year?
When I enter a temperature schedule for the ventilation system, the Exporttoopenstudio component comes with the error " Airloop needs at least one fan." It does not make sense for me, since there is already a fan connected to the ventilation system. Do I need to add a fan?
Lastly, I want the air volume to be a variable of the zone operative temperature. By that, I mean that the operative temperature from the previous time step is used to calculate the air volume in the next timestep. I connected the resulting output of the operative temperature into the variable, but it comes with an error saying that the ReadEPResults cannot depend on itself. Is there an easy way to make this work?
I have also looked at the openstudio GUI to solve my problems, but since I have never worked with GUI, it was really difficult to figure out the program.
I hope that some of you can help with my question.
