Donna Ohl, Grady Volunteer Coordinator wrote:

Do any of these choices seem most reasonable to replace my existing 65
gallon First Hour Rating, ??EF, 40 gallon, 35,000 BTU 50" tall by 18"
diameter gas-fired shelf-mounted earthquake-strapped hot water heater?

It would be nice if there were freeware to do all these calculations for
us! (I'll ask the wonderful folks on the freeware newsgroup if they have
any "special" cost-per-FHR calculators other than standard calculators).

Nope.

Susan