DHW instantaneous

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Hello,

I am trying to model an on-demand gas hot water with an efficiency factor of
.93 from the manufacturer (Rinnai). ASHRAE says to model the baseline
according to Table 7.8 which shows an Energy Factor of .62. My .93 unit
should be showing significant improvement in the model in the domestic hot
water, but my baseline case (with the .62) is showing slightly LESS energy
usage than my design case with a .93??

My process was to select the gas instantaneous in the wizard for my design
case. Create LEED baseline file. Then adjust the Energy Factor in the LEED
baseline file.

Any thoughts would be greatly appreciated.

Thank you,

Joe Snider, AIA, LEED AP

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I believe I answered my own question after further digging in the archives.
Thank you to those who came before.

Looks like one needs to enter the HIR to achieve the proper inputs. The HIR
according to other is 1 / EF. When adjusting the inputs accordingly, I am
now showing significant savings over baseline from my high-efficiency
on-demand hot water heater.

Thanks again for this great resource.

Joe Snider, AIA, LEED AP

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Joined: 2011-09-30
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