On Tue, 12 Feb 2008 20:12:51 -0500, Lou wrote:
Also, all the back and forth about the relative cost of operating a smaller
heater compared to a larger one seems to me to be fairly easily resolved -
take a look at the energy guide

It turns out a lot of people were dead wrong on efficiency, including me.
According to the www.gamanet.org web site, operating a 40-gallon hot-water
heater is no more or less efficient than operating a 50-gallon hot-water
heater.

The only thing that matters for efficiency is the Energy Factor (EF) which
takes into account the tank size, insulation, and burner BTU.
Reference site: http://www.gamanet.org/gama/inforesources.nsf

So, if a 40 gallon hot-water heater has an EF of, say, 0.63 while a
50-gallon hot-water heater has an equal EF of 0.63, then the costs are
EXACTLY the same to operate the two heaters!

The math is all spelled out for us in the PDF at:
http://tinyurl.com/38eh4d
http://www.gamanet.org/gama/inforesources.nsf/vAttachmentLaunch/C2AAFB8D41D003F485256E9000607F66/$FILE/12-07-gas-rwh.pdf

Since almost all of us were dead wrong on this one, it would be nice if
someone can read that reference document and let me know if my new
conclusions that size doesn't matter has any flaws in it as I publically
state that all that matters is the EF (based on my reading ten times of
that document).

Donna