Standby Losses

The standby loss (SL) is maximum Btu/h based on a 70°F temperature difference between stored water and ambient requirements. See the note at the bottom of Table 7.8 for the SI equivalent units.

The formula for a greater than 12 kW electric water heater would be -
20 + (35 x square root of V) = SL

Correct for the smaller heaters you calculate EF and not SL.

Hi Marcus

I appreciate if you give me more statistic about below item:
"for the smaller heaters, you calculate EF and not SL."
I searched a lot and I could not find anything. I checked some manufacturer's catalog and they did not consider SL for smaller Elec. Water Heater and they mentioned just EF for smaller one.

I also checked the Std and I could not find any related information.
Tnx

That sounds right. The smaller heaters should have an EF and not a SL.

I could not find it on any standards.
Could you please help me with this matter. I should fill in the form for the municipality and I need some statistics document

I am not sure I have seen this on any manufacturer's literature for water heaters. We simply calculate it using the formula in Table 7.8.

Could you please tell me the name of Std that we can find the formula in Table 7.8?

90.1

Thanks for your reply, I checked Table 7.8 "Performance Requirements for Water-Heating Equipment" in "ANSI/ASHRAE/IES STANDARD 90.1-2016. 
For Electric water heater less than 12Kw and bigger than 75.7 Liter, refer me to "Footnote (g).

In the footnote (g), write this sentence "in the U.S. refer to CODE OF FEDERAL REGULATIONS 10 CFR Part 430. I checked it and unfortunately, I could not find any related data.

I am looking for Std which applicable in Canada.

In my project, I have 9Kw Electric Water Heater and 50Gal(178Liter)
I appreciate if you have more information, please tell me.

90.1-2007 is the referenced standard for this version of LEED.

I am not sure what applies in Canada.