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Dear TRNSYS User,
I’m modeling a 3 floors office building in TRNSYS 16 and comparing the results to those of EnergyPlus(E+). Using Energy Rate method in TRNSYS, I estimated the peak cooling and heating load which found to be the same as those from E+. I accordingly used them to size my HVAC system (package unit to supply air at 12.8 deg C) and then provide VAV and reheat for tune up at the zone level. Since no VAV component is available in TRNSYS 16 (unless I buy it!), I had to make one simple model myself using equations to vary the mass flow rate for each zone based on the zone load and thermostat response.
The problem: My VAV damper modulating mechanism is based on the response received from the
zone. This response is dependent on the internal load for the Core zone for example (or
zone load for perimeter areas). In E+, lighting load contributed to the zone is
only 60% and 40% of that will go through the return air without contributing directly to
the zone. However, the TRNSYS Model sees the entire lighting load at the zone
level and therefore the zone load is higher than those seen in E+ which makes
the mass flow rate higher.as well Since my VAV response is based on the zone load
rather than the system load, is there a way to have this division in TRNSYS
where I could match the zone loads. I would like to mention that both models give
a reasonable match at system level which is good for energy estimation. I’m interested at zone level at this moment of time but still needs a reasonable results for energy consumption. Therefor, total lighting load is needed for energy calculation but some sort of reducing it at zone level is sought.
Thanks, Saleh NJ AL-Saadi University of Colorado at Boulder Department of Civil, Environmental and Architectural Engineering |