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NC-2009 EAp2: Minimum Energy Performance
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EQUIPMENT CAPACITY OVERSIZING
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Jean Marais
b.i.g. Bechtold DesignBuilder Expert832 thumbs up
November 9, 2012 - 2:06 am
Very good question. Ideally all the systems, but if I were a reviewer, I would only look at the fan(s), chiller and boiler sizing. Here the sizing has the greatest impact on efficiency. If your coil is oversized, it may only impact on the pumping power. Pumping power inturn is very roughly estimated as no pressure drop in the piping is required to be dynamically simulated in the simulation. For the baseline pumping power is a function of mass flow. Electrical equipment is also not that critical in my opinion. Most softwares are limited in what they can actually size, by internal model assumptions.
Anyone else?
PAWAN DAHIWAL
10 thumbs up
November 9, 2012 - 3:22 am
thanks sir. your comment really help me. I little bit wondered when i listen from my colleague that, oversizing can be done at system level or zone level but not at both. according to me, system level is what we can say it a source which generate a medium for HVAC it may be include but not limited to boilers, chillers etc but i am not confirmed about zone level, it might include fans or else. So, according to you can we oversize these all parts by 25 and 15 %?? Any thoughts??????
+++++ can you please give me more info on zone level equipments oversizing?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
November 9, 2012 - 10:22 am
Correct it can't be done at both the system and zone level. In general it is done at the zone or the plant level, usually the zone level. Again it can't be at both.