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why the simulation in designbuilder can't give HVAC results

asked 2020-09-23 07:25:02 -0500

oussama-ka gravatar image

updated 2020-09-23 16:12:12 -0500

I'm using designbuilder , and in my project, in some zones i used the simple HVAC [VRF cooling] (i get a warning message when using a detailed HVAC) so when i stimulate in the zones where i applied the HVAC, i got the result below(1) which i found contradictory to the results in (2) especially in the temperature diagram for my project i want to know the electrical consumption of the HVAC system in some specific zones and their thermal comfort diagram:

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and for the next question why in the diagram of hours of discomfort i have the discomfort in the period when my HVAC cooling system is working logically between 8AM and 6PM in 15 JUL those hours people should be in thermal comfort because of the cooling system

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answered 2020-09-24 04:09:50 -0500

Filipe Sousa gravatar image

Re. question 1, In DesignBuilder, the Fuel consumption output is not available at zone level. However, with Simple HVAC (Ideal loads) you can estimate the HVAC electric consumption by multiplying the zone level System loads graph output by the COP entered at the HVAC tab. With 'Detailed HVAC' the energy consumption is an output available for each equipment. This can be checked on the simulation epluoust.eso file using DesignBuilder Results Viewer tool.

Re. question 2, The Discomfort hours data is based on whether the humidity ratio and the operative temperature is within the region shown in ASHRAE Standard 55-2004. In the summer when the air is very humid operative temperatures above 26.8°C / 80.2°F are considered too hot with summer clothes. The operative temperature at your screenshot seems to be above 26.8°C. You may need to review the cooling temperature target for this space to meet the ASHRAE Standard 55 comfort levels.

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Asked: 2020-09-23 07:25:02 -0500

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Last updated: Sep 24 '20