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Any suggestion why the load results are not reasonable!!!

asked 2019-05-23 07:27:17 -0500

Mamak's avatar

updated 2019-05-27 15:24:40 -0500

Hi every one, I have modeled a building in open studio with ideal air load.... the heating load results perfectly match the data I have ...but the cooling load is nearly 10 times higher than what i have expected!!!! I have checked the input data manay times, But i did not understand the problem.... Any one can help me to understand why the cooling load is that much high?!!!! Thanks

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link to your model and data. could be a wide range of things - internal load values and design day schedules, design day choices, system or zone sizing, outdoor air settings. We can't help without more information on the model and what you've already tried.

mdahlhausen's avatar mdahlhausen  ( 2019-05-23 10:22:52 -0500 )edit

Thanks for you comment. I have modeled the building, without any HVAC, defining ideal air load (unlimited)...I did not defined any design day, or system sizing and not set the outdoor air specification... I have done the model in this way to analyze the energy need just considering the bulging envelope...The internal load I have checked manay times...So I have no idea where the problem is:(

Mamak's avatar Mamak  ( 2019-05-23 13:26:38 -0500 )edit

can you post a link to your model?

mdahlhausen's avatar mdahlhausen  ( 2019-05-24 11:08:54 -0500 )edit

This is the link of the model: Thank you very much for your help .

Mamak's avatar Mamak  ( 2019-05-24 13:13:37 -0500 )edit

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answered 2019-05-24 18:23:13 -0500

updated 2019-05-27 13:14:46 -0500

This is likely related to your earlier question. I'm not quite sure how you managed to get results for cooling load without inputting cooling design days.

Regardless, your model does not contain ventilation, so heat builds up in zones rather than leaving through exhaust air. I suggest adding design specification outdoor air objects to your conditioned spaces and adding design days, then re-running and re-checking the result.

Design days are peak conditions for heating and cooling and are necessary to autosize your system. You can find the design days (in .ddy files) along with the .epw for the location. epwmap has a map to help you find design days for your location.

In OpenStudio, here is where you input design days: image description

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Thank you very much for checking the model. Actually I’m running the simulation to analyze Energy need Just considering the building envelope ...this is why I have used Ideal air load and added natural ventilation to the thermal zones in thr “zone equipment “ part....So this is not true?Should i add the design outdoor air specification?!!!

Mamak's avatar Mamak  ( 2019-05-24 19:19:50 -0500 )edit

Regarding the design days, I know that it would be used for HVAC I am pretty new ,I am not sure about it and maybe i am wrong...So can you tell me what is design day for,??? Should I use it in the simulation with the aim i have explained?...How can I identify and defined it... I really appreciate your support

Mamak's avatar Mamak  ( 2019-05-24 19:20:59 -0500 )edit

Thank you very much for your explanation. I really appreciate your support.

Mamak's avatar Mamak  ( 2019-05-29 03:50:56 -0500 )edit

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Asked: 2019-05-23 07:27:17 -0500

Seen: 422 times

Last updated: May 27 '19