On Apr 9, 2:30*pm, wrote:
On Apr 9, 11:11*am, Wayne Whitney wrote:





On 2008-04-09, wrote:

note it appears in homes that use more water, the typical 2 adults and
2 teenagers savings are less, probably because the standard tank
spends more time heating water and less time standing by. this is a
new wrinkle on the tank vs tankless discussion

Actually, it doesn't say the savings are less, it says the efficiency
improvement is less. *Standby losses are basically independent of
usage. *The greater the usage, the smaller the fraction of total costs
attributable to standby losses.

So if you are trying to calculate a payback period, and if the
incremental efficiency of the tank and tankless are the same, then
usage doesn't matter. *All you need to do is figure out how much more
expensive the tankless is, and how your savings from standby losses
are.

Cheers, Wayne

Yes, I was going to point that out too. * Sure, in percentage terms,
the more hot water you use, the less in percentage terms you will save
on your energy bill. * That's because the big difference is the
standby loss, which is independent of the amount of water used.
However, in dollars saved in gas saved per year from standy losses,
it's still going to be the same amount of money saved, which is what
you need to look at.

Also, am I the only one that thinks it odd that if a tankless has a
pilot light it would negate the entire energy savings compared to a
regular water heater? * The regular water heater has a pilot light too
and I would think the overall impact of a pilot light might be a
couple %.- Hide quoted text -

- Show quoted text -

I am now at a tank location, my last summers gas bills are double and
more than at the tankless location, 9 vs 12$ a month. Same gas dryer,
same gas cooking. So Tankless saves me 13 or so a month at TODAYS gas
prices. Wait 5 years. my payback is 5 years and less and declining as
prices increase. Tankless-pilotless, work and outlast tank , which
looose 1-3 % efficency every year due to scale.