The best heat source for drying is electric. When burning propane the
exhaust side of the heater will be very humid. If the heater is with in the
heated environment you have a humidity problem. Diesel may have the same
problem.


"bligh" wrote in message
...
Hi, I searched for a while but found no cost comparisons. I'm looking
at the Force 10 6k btu model for an uninsulated 23' fiberglass boat
of approx 900cf. It comes in two different models. Is gas cheaper than
diesel in terms of operating costs? Also, many people said neither
fuel will dry the boat out. I don't quite understand how something can
produce heat and not dry things out but I'm sure anything's possible
these days. I'm thinking of a long trip in daily drizzle. Thanks for
your time and smooth sailing everyone.

The key thing, if dryness is important, is a stack or chimney. The exhaust
turns the heater into a ventilation blower.

Propane and diesel contain lots of hydrogen which is a big part of where the
energy comes from. That's why they call them "hydrocarbons". When hydrogen
burns, the ash is water. If your heater isn't vented, all that water ends
up in the cabin air. You're adding water to the air as fast as the heat is
drying it.

If you can find one, it's really hard to beat one of the miniature solid
fuel stoves. You can break those fake fireplace logs into chunks for quick
heat and then throw some coal on top for long heat and a really traditional
smell.

--

Roger Long



"bligh" wrote in message
...
Hi, I searched for a while but found no cost comparisons. I'm looking
at the Force 10 6k btu model for an uninsulated 23' fiberglass boat
of approx 900cf. It comes in two different models. Is gas cheaper than
diesel in terms of operating costs? Also, many people said neither
fuel will dry the boat out. I don't quite understand how something can
produce heat and not dry things out but I'm sure anything's possible
these days. I'm thinking of a long trip in daily drizzle. Thanks for
your time and smooth sailing everyone.

bligh wrote:
Hi, I searched for a while but found no cost comparisons.

It's like doing homework.

... I'm looking
at the Force 10 6k btu model for an uninsulated 23' fiberglass boat
of approx 900cf. It comes in two different models. Is gas cheaper than
diesel in terms of operating costs?

Depends very largely on whether or not the boat already has diesel
tanks. If yes, then putting in a diesel line to the heater is a bit less
trouble & money than putting in propane. OTOH if you can tap a propane
line to the stove then that might be easier.

In terms of $$/btu I think diesel wins but that is a small factor unless
you live in a very cold climate

... Also, many people said neither
fuel will dry the boat out. I don't quite understand how something can
produce heat and not dry things out but I'm sure anything's possible
these days.

Hydrocarbon fuels (almost every type including gasoline, diesel, and
propane) are combinations of hydrogen & carbon, with slight amounts of
various other stuff mixed in. "Burning" is a process of combining it
with oxygen... same thing your lungs do. Combining carbon with oxygen
produces CO2, like you exhale, and CO, which hopefully you neither
exhale nor inhale... and H20, which you also exhale but hopefully don't
inhale! Putting H2o vapor into the air makes it damp, voila.

The answer is to have a chimney which carries the CO and H2O outside the
boat's cabin. Thus youo get heat with no damp. However those pocket
heaters & freestanding floor heaters put moisture into the air and can
actually result in a boat that feels clammy & chillier than before
lighting the heater.

A chimney on a boat is kind of a PITA. It often leaks and it tends to
catch toes & lines. But there are ways to minimize this kind of trouble.

Fresh Breezes- Doug King

"bligh" wrote in message
...
Hi, I searched for a while but found no cost comparisons. I'm looking
at the Force 10 6k btu model for an uninsulated 23' fiberglass boat
of approx 900cf. It comes in two different models. Is gas cheaper than
diesel in terms of operating costs? Also, many people said neither
fuel will dry the boat out. I don't quite understand how something can
produce heat and not dry things out but I'm sure anything's possible
these days. I'm thinking of a long trip in daily drizzle. Thanks for
your time and smooth sailing everyone.

The diesel bulkhead heaters burn approximately 1 gallon of fuel in 24 hours.
Offhand I don't recall the consumption rate for propane but I'm sure Force
10 or Dickenson can provide you with this information. In a small boat
propane may be economical and its much easier to use than a diesel heater.
The diesel heaters need to be run at a fairly wide open setting to prevent
soot build-up. With a 6000BTU heater running full bore in a 23 footer you
will be very warm.
A propane unit has the advantage of almost infinite heat setting although if
you turn it down too low it might be blown out by a backdraft. I believe
they have an automatic gas shutoff feature in case this happens. Propane
units also require a vent stack that is only 1 inch in diameter vs the 3
inch diesel exhaust (you need to cut a 5 inch hole in your cabin top for
this stack so that 1 inch of clearance is on all sides). All in all I like
propane but I think it tends to be fairly expensive for long term heating.
For daysailing its more reasonable.

As for not drying the boat out, if you warm the air in the boat it will hold
additional moisture and therefore remove dampness. As this air goes into
the unit as combustion air and out the stack it will take moisture with it.
If you had the combustion gas entering the cabin this would introduce
moisture but I can't imagine anyone doing this with any reasonably large
heater. Its a good way to poison yourself, especially with a coal/charcoal
burner as these produce large amounts of carbon monoxide. Warm air leaking
out of the boat will also take out moisture. Cold air entering the boat
will bring in some moisture but on balance you should dry things out. It
may take a while depending on how wet everything is.

One thing I have noticed while living on my boat in cold weather: even with
my thermometer registering a reasonably warm air temperature it often feels
chilly. I think this is because the hull, cabin top and other surfaces
remain cold. Heat radiates from a warm body (yours) to a cold body (the
hull) and consequently you feel chilled. Fortunately a sweater (cardigan to
the UK folks) solves this problem.

In terms of $$/btu I think diesel wins

and wins hands down. propane has about 90,000 btu's per gallon (about 4
pounds) while a gallon of diesel has nearly 150,000 btu's. Not sure what I
paid per gallon for propane a year and a half ago (I had installed the new and
required anti-overfill value at the same time) but think I paid about
$5/gallon. Diesel, even today, even at the gas station is about $2, or about
40% of the price of propane per gallon for about 67% more heat value. Or
diesel costs about 25% of the price of propane on a heat content basis.

You might think about getting and transporting the fuel.

Mike

bligh wrote:
Hi, I searched for a while but found no cost comparisons.

Do your own.

Propane contains about 15,000 BTU's per pound and a U.S. gallon weighs
about 4.25 pounds.

Diesel contains about 21,500 BTU's per pound and a U.S. gallon weighs
about 7 pounds.

Obtain your local prices and do the math.

Rick