Hi All,
In Appendix G Table G3.1 Page 178 Paragraph 11 about
Service hot water heaters it is written

The service hot-water system in the baseline building design shall use the same
energy source as the corresponding system in the proposed design and
shall conform
with the following conditions:

a. Where the complete service hot-water system exists, the baseline building
design shall reflect the actual system type using the actual component
capacities
and efficiencies.

b. Where a new service hot-water system has been specified, the system shall
be sized according to the provisions of Section 7.4.1 and the equipment shall
match the minimum efficiency requirements in Section 7.4.2..

I didnt get what is difference between a and b

Suppose if we are showing energy saving between baseline and proposed
case through solar heaters which are installed in proposed Case then
what heater shall we take in baseline (Electric? Gas ) and which
should be its efficiency and Baseline thermal conductivity of Storage
tank

Thanks
Sambhav