PMV analysis on designbuilder

asked 2018-03-16 08:27:07 -0500

RicardoPereira
201 ●1 ●1

updated 2018-03-16 10:18:32 -0500

__AmirRoth__

4436 ●5 ●17 http://bleedinggreenna...

It is more a "philosophical" question here,

So I am working on a project where we are given a terrible performing building and we have to improve it within a budget. I have spent 40K euro and cut my operational cost from 120K to 50K (most part of that is from using better light bulbs). The other thing we could change were the setpoints for the HVAC, the base case had 20 and 21 for heating and cooling setback and setpoints... I changed to 12 / 22 for heating and 26 /32 for cooling. Right after all these changes, I went to look at my productivity based on the PMV... I filtered just the working hours of my building and filtered also just the areas where I get work done (excluded toilets for example)... And my productivity went down from 64K to 58K. It is totally against what I was expecting... I am giving a warmer climate during winter, cooler during summer, reduced glare and excessive daylight... why my PMV decreased....is there anything else in the big picture I can not see?

thanks

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answered 2018-03-22 13:13:11 -0500

Kyle
55 ●4

I am far from an expert on HVAC issues, but consider that some facilities stay on all the time overnight all year in order to avoid having to expend start up energy. It may be possible that allowing the building schedule to include "off" time means that when your system turns on at the beginning of the week it has to expend alot of energy to return to the set point. This may require more energy (ie money) than just maintaining consistent set points. Check your custom schedules for wide swings in set points, basically big changes in your demand in a short amount of time. Ramping up over time may be better or just avoiding jumps may improve cost efficiency.