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ideal air loads - maximum heating capacity

asked 2015-02-23 09:06:34 -0500

updated 2015-11-10 21:27:50 -0500

Hi all,

I am working at an architecture firm and getting to know the sketchup plugin and openstudio application. I have the results and parameters used for simulating an existing design from an engineering firm, they used designbuilder.

Now i am trying to achieve the same results with the sketchup plugin and openstudio software.

Because i am not sizing any HVAC installations and do not need to in the future it would be nice if i could achieve the results without any HVAC templates. (I am just calculating the net energy use per square meter so i don't need to use any HVAC).

In the engineering firm they used a simple HVAC, gave it a 100% efficiency and put it on a schedule. We can't put the ideal air loads on a schedule in the openstudio application but i achieved the same effect by putting the thermostat for heating very low during night time en very high for cooling during night time.

There is still a significant difference between designbuilder and openstudio results however and this is because there is obviously a maximum heating capacity in the standard HVAC put in in designbuilder.

The results below show the inside zone temperature and the heating energy for a couple of weeks in designbuilder (blue) and openstudio (red).

Inside temperature

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Heating energy

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I understand the ideal air loads in the openstudio application is restricted to the simple check box. I tried to fill in the following variable in the idf file before simulating: Maximum Sensible Heating Capacity But this seems to make no difference.

Does anyone of you know how to set this maximum heating capacity? Is it nog the sensible heating capacity parameter? If it is only possible to do so with a standard HVAC template where would be a good place to start reading?

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Really nice question. Just for reference, I'll provide the link to the related question.

David Goldwasser's avatar David Goldwasser  ( 2015-02-23 10:26:36 -0500 )edit

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answered 2015-02-26 10:08:45 -0500

I suggest that you use a packaged single zone system from the OpenStudio template. It is almost as easy as turning on an ideal air system, and you have full control to configure hours of operation, capacity, etc.

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Asked: 2015-02-23 09:06:34 -0500

Seen: 1,313 times

Last updated: Feb 26 '15