We are working on a large hotel, and are concerned with the "Modeled DHW Flow Rate gallons/minute" results we are getting from the "Service Water Heating" portion of the calculator. We've double checked everything against the "v4v4 1_Indoor Water Use Reduction Calculator_v04_0", and all the values seem inline.
However, we're concerned by the low flow rates from the results. the calculator gives us a baseline modeled flow rate of 1.970 gpm, with a proposed modeled flow rate of 1.053 gpm. These amounts seem low for a 175 unit hotel. Is there an input we're missing elsewhere, that will bring these values into line wit the expected DHW flow rate? Thanks in advance.
Waleed AlGhamdi
Sustainability EnablerEskew+Dumez+Ripple
20 thumbs up
September 12, 2019 - 3:30 pm
I haven't faced this particular issue. But, on the "General Information" tab on the minimum energy performance calculator, try changing the answer to "Project has residential Dwelling Units?" and see what happens. If your original answer was no, then changing to yes might factor in the showers and increase flow rate. Note that this answer pops up a new tab for "Multifamily" which is different than the service water heating tab intended for commercial buildings. I'm not sure if this will be the most accurate approach since hotels aren't typically occupied at 100% capacity 24/7, which is the fair assumption for multifamily.
And in general, yes, the figure you're showing seems small.
Kyle G. Pearson
3 thumbs up
September 12, 2019 - 3:50 pm
Thank you. I tried the change you suggested before, but missed the multifamily tab. I’ll see what it entails.