Re: OT / Tankless Heating

[Lee Hart <leeahart@earthlink.net>]

>> 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.

Eric Jelinski wrote:
> Sorry; try exergy analysis.

What is the definition of "exergy", please? I don't find it in any of my
Physics, Thermodynamics, or Heat Transfer textbooks.

> Exergy analysis takes into account the entropy lost...

Entropy I understand (or, I did when I passed my thermodynamics finals
:-)

I think I get your point. Burning fuel remotely at a power plant to make
electricity, to generate heat on your home is inefficient, too. But I
was simply looking at the microclimate. You pay for X amount of energy
to come into your home. If you want hot water, 100% of the electrical
energy gets converted into heat inside your water heater. If you burn
gas, only a fraction of that energy heats the water; the rest heats the
air, the chimney, etc. You need more BTUs of fuel with gas, but at
current prices, you'll pay less per BTU for gas than for electricity.
-- 
Lee A. Hart                The three laws of thermodynamics (simplified)
814 8th Ave. N.            1. You can't win.
Sartell, MN 56377 USA      2. You can't break even.
leeahart_at_earthlink.net  3. You can't stop playing the game.