Hello!
I'm working on modeling a Student Learning Centre and am having a bit of trouble with modeling an HRV. I go to the Air-Side HVAC and edit the Heat Recovery to say:
Device Installed - Yes
Device Type: Sensible HX
Effectiveness: 0.7
with everything else left as defaults to each of my systems. In my end results, my Domestic Hot Water and Space Heating are over 97% better, and my cooling is 50% worse than the reference. These numbers aren't making sense but I can't find much help anywhere with HRV in EQuest. Any help you could provide would be great!
Thanks!
Samantha MacHardy, B. Arch. Sci.
hrv/erv savings are all about controls. the default setting is on when
system fans are on. this can easily cost you more money & energy than
not having the erv at all.
if the project is not designed for the hrv to operate on a delta t
between the exhaust air & outside air this isn't really obvious. i
suggest changing the control type to delta t & try a few different
amounts. 10 d f, 15 d f, 20 d f & see what the results are. these can
also be set up with an eem so you don't have to keep changing the main
system & seeing what the results are.
look in the march 2012 ashrae journal. there's an article explaining
how to control a total energy wheel & the 2nd paragraph or so actually
says an uncontrolled erv can result in more energy & more cost. though
you only have an hrv the concepts in the article will still apply for
heating mode of course.
I changed the Make-up air temperature control to "Mixed Air Reset" and this solved the problems I had with Cooling and Fans. I took your advice with changing the control type and Delta T but the best I can do is reduce it to be 93% better than reference instead of 97%. I've tried fiddling with different options and am still having way too much heat being produced.