Re: OT / Tankless Heating

[Eric Jelinski <jelinski@idirect.com>]

At 01:10 AM 1/27/01 -0800, somebody you wrote:
>First, resistive heating elements are by definition 100% efficient.
>Every last KW is converted to BTUs. No gas burner can come close to
>matching this efficiency. 

Sorry;  try exergy analysis.   No, it is not energy analysis miss-spelled.
 Exergy analysis takes into account the entropy lost   (I know I've lost
everybody on the list by now)    Basically after the temperature difference
between point of energy conversion and temperature of use is taken into
account... the greater this temperature difference the greater the losses.
 Exergy analyis for space heating shows that electric space heat is only
about 10% efficient.   I have not calculated for water heating, but on the
basis that water temperature of use is ~ 25 deg C about the same as room
temperature ~20 deg, relative to temperature of combustion in a fired
boiler added onto the front end to heat water to steam, drive a turbine,
rotate a generator, send amps down long transmision cables, etc, I expect
it is also about 10deg C efficient.  A small electric point of use water
heater is more efficient than a big tank water heate ras somebody said.   A
small gas fired water heater (point of use) would be most efficient.
Having a fuel cell in the basement fed by natural gas and creating
electricity and heat byproduct ot also heat water would be thee most
efficient.
regards,   Eric