Shall I modify the rated cooling capacity of the VRF Air conditioner to reduce the cooling unmet hours that download from the BCL?

asked 2019-08-01 06:40:56 -0600

Prasanth M's avatar

updated 2019-08-01 19:51:56 -0600

I am simulating two storey building with VRF system having 14 thermal zones. I used 6 TR rated cooling capacity system that is downloaded from BCL, which gives more unmet hours. Then I increased the rated cooling capacity of the same system, the number of unmet hours reduced. Then I replaced that with 8 TR VRF system downloaded from BCL, it consumes lesser energy than the 6 TR system. I want to know whether this is correct or not? Thanks in advance.

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did you download a measure or a component, and which one?

mdahlhausen's avatar mdahlhausen  ( 2019-08-01 10:24:38 -0600 )edit

First I thank for your reply, I downloaded both 6 TR and 8 TR systems from BCL component. My building total cooling load is 7.4 TR, my conditioned zones cooling load is 5.7 TR, so I first used 6 TR VRF system downloaded from BCL component and I simulated, the number of unmet hours was 1600 and energy consumption was 10300 W. After I replaced 6 TR system with 8 TR system which is also downloaded from BCL component and I again simulated, now the unmet hours reduced to 20 hours while the energy consumption is 8800 W. Is it correct?

Prasanth M's avatar Prasanth M  ( 2019-08-01 23:27:04 -0600 )edit

so you download components.

A few notes: - Run the 'NZE HVAC' OpenStudio measure with the VRF option to add VRF to your model, and then replace the componentry with the VRF component you want from BCL. - Watts isn't a unit of energy consumption, so I'm not sure what you mean by energy reduced. - There could be lots of reasons for unmet hours. Run the unmet hours troubleshooting measure available on BCL and follow its recommendations.

mdahlhausen's avatar mdahlhausen  ( 2019-08-02 10:20:24 -0600 )edit