[TheForge] Shop heat - hot water heater

[Jerry Frost]

Running hydronic heat with a water heater is becoming 
pretty common, even here in Alaska. Efficiency ratings 
for a tank type water heater are so low primarily 
because it is trying to keep a tank of water up to temp 
whether it's being circulated through the heating 
system or not.

If you use a tankless water heater like the Rinnai or 
Paloma you get efficiencies in the mid to high 90%'s. 
They're spendy but payback especially for domestic hot 
water is reasonably quick. The Feds are also offering a 
rebate for converting to or building with energy 
efficient technology. I hears on Paul Harvey the feds 
were rebating up to $300 for buying a Rinnai. Rinnai is 
uncle Paul's sponser and I imagine the fed rebate is 
good for any tankless water heater but check before 
counting on it. <grin>

There's nothing wrong with natural gas for a forge fuel 
though there are some consessions you'll have to make. 
It's difficult to get enough psi on a delivery line to 
run a naturally aspirated burner so you're probably 
farther ahead to just go with a gun (blown) burner from 
the start.

Don't let the BTUs/cu/ft fool you; sure methane 
contains fewer BTUs/cu/ft than propane but the Air:Fuel 
ratio is more favorable and goes a long way to making 
up for it. Propane's air:fuel ratio is 16.5:1 for a 
neutral burn and somewhat less in a forge for a 
reducing atmosphere. Methane's air:fuel ratio is 10:1 
and again somewhat less for a reducing atmosphere.

The substantially lower volume of air means less 
nitrogen which acts as a heat sink in a flame so a 
methane burner will perform as well in a furnace as 
propane. Methane is cheaper than propane per BTU as 
well so there's a monetary advantage.

Using methane in a portable application isn't very 
convenient but certainly possible. If you live on a 
coast, maybe on or near a large lake or in a city that 
promotes it, you can buy CNG (Compressed Natural Gas) 
which can be used just like propane in a naturally 
aspirated burner. You must adjust your jet size for the 
different air:fuel ratio of course.

Marinas sell CNG for use in boats, being lighter than 
air it doesn't collect in the hull like propane can and 
explode. Exploding your boat is. . . BAD. <grin>

Frosty
-------------------------------
If it ain't forged
it ain't real.
Wrought iron is.
The FrostWorks

Meadow Lakes, AK.

http://www.artmetalradio.com/