Date: Wed, 16 Feb 2005 21:02:29 -0500
Reply-To: "T.M." <tinkerman007@YAHOO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "T.M." <tinkerman007@YAHOO.COM>
Subject: Re: Cabin Heat / Aux Heating / Propane Heater/ camping heater /
pics
Doug,
This is the most BRILLIANT DIY idea I've ever seen for heating the
vangon!!! And your idea of placing it in the body cavity is also superb!
At first I was scared about a DIY heater project involving propane, but
after carefully reading your description and seeing your clear pictures I
concluded that you have a great idea. I wonder why it hasn't drawn much
more attention (probably because it's a highly technical project with some
underlying danger if you don't do things right, but IMO you have included
many safety features that make it quite a safe solution).
Also, your adherance to relatively easily available parts and technologies
make it quite a feasible project for any relatively capable DIY'er.
Now to some practical questions:
1. How much BTU do you estimate those two mantels put out (or propane
consumption per hour, which can give an estimation of BTU).
2. Since you said it's a little underpowered, don't you think it could be
expanded with a few more mantles or even by using more powerful compact
portable stove burners?
3. From what material is the electrical box made of, and which welding
technology did you use?
4. Although you say the vented combustion products are barely hot ("You
can just barely sense a slight temp change of air at the outlet") wouldn't
it be risky using a plastic CPU fan for the task in case the outgasses got
hotter and melted the fan? BTW, your design takes care of that too,
because as you said the mantles would go out if the fan stopped and then
the thermocouple would shut the propane supply.
5. Wouldn't it be safer to add an overheating shutoff function? That would
be difficult IMO, as I don't know of any overheating shutoff valve
available (the thermocouple is an "underheating" shutoff valve). The only
way I can think of is an electronic thermoswitch coupled with an
electrical gas valve (which I don't think is an available product). So at
least a electronic thermoswitch coupled with a warning buzzer to alert you
to turn of this heater before it gets out of control...
Let me salute you for a great idea!...
cheers, TM
On Tue, 16 Nov 2004 15:44:50 -0800, Doug in Calif <vanagon@ASTOUND.NET>
wrote:
>Well Volks,
>Especially those of you who are doing the winter camping thing and are
dealing with the COLD.
>Here is a heating idea that I have put together for my bus, that I would
like to share with the group, especially those of you who typically think
out of the box and design your own solutions. This is one of the greatest
values of the list in my opinion. I am constantly getting fantastic ideas
from the group.
>I have finally completed another one of my Syncro GL to westy conversion
projects.
>The completely "HOME GROWN Primus Lantern mantle fresh air heater". "Ta-
da!"
>
>Some of you will surely say I have too much time on my hands which I wish
was the case. Rather, I really really enjoy and get a great deal of
accomplishment from projects like these.
>I think it is a shame there are not more "fresh air" heating options for
the vanagon.
>I wanted a heater that would completely vent intake and exhaust air to
the outside of the van and would have zero emissions and oxygen depletion
inside the van.
>I wanted a heater I could sleep right next to with absolutely zero worry
that I may wake up "dead" from depleted oxygen or build up of carbon
monoxide.
>I have looked at pretty much everything out there and the Propex is the
one I really like but its not cheap and I could not install it where I
installed this one in the side body cavity.
>I have done some initial tests now with my completed project and I feel I
achieved what I wanted.
>
>By using two Primus lantern mantles re-jetted for the low 1 psi pressure
of the regulated westy tank I am able to generate a decent amount of heat
for the
>rear sleeping area of my syncro. I started with a basic ten dollar
electrical box from my local yard birds, seal welded in eight 3/4 inch
metal tubes to act as a fresh air heat exchanger.
>I used two hot water heater copper flex lines to vent intake and exhaust
air to the side air duct at the rear of the van. I am using a thermocouple
from a parted out westy fridge to shut off the propane in the event the
mantles should go out. Wood stove ceramic glass for a window in the face,
wood stove door seal rope for the seal of the face. I made a hinged cover
to hide the light from the lamps. 4 inch 107 cfm 12vt box fan draws 1/2 an
amp for the main blower, 10ohmm resistor to gives the fan 2 speeds, a
thermal 160 degree snap switch mounted on the top of the heater box cycles
the blower fan on and off. Webber bbq Pizo ignighter lights the first
mantle and once lit, the 2nd mantle will light from it. I found out the
hard way that the unit would not "draft" as it did on the bench test, once
I had installed it in the van, the box filled up with propane to the level
of the pizo before igniting, my heart is still recovering from that event.
I ended up installing a small 1inch CPU fan to the far end of the exhaust
run which I ran all the way to the top of the air intake behind the
plastic louver intake. You can just barely sense a slight temp change of
air at the outlet. Which means that most of the heat from the mantles is
being extracted by the heater. Installing the combustion fan on the
exhaust side and drawing a "vacuum" on the heater box is the best way to
install a combustion blower because any leakage will draw air into the box
and exhaust it. If you install the combustion blower on the intake and
create a pressure to push the air, any leaks will come into the van. I
believe I have a good seal as with the blower off the mantles use up all
the air quickly and go out.
>
>I used bubble foil behind the heater and around the heater to create a
proper air duct for the blower fan to push the air through the heater. I
used fiberglass header wrap on the back of the heater box itself as it
gets pretty warm, also a small section of the body metal behind the heater
where its a bit close. My testing running the heater for long periods show
only a small warming of a few degrees of the body metal when you feel it
from the outside, hardly even noticeable by feel.
>
>The amount of heat is not huge, I do not think you could heat the whole
van effectively unless you had really good insulation and ran the heater
for a long time. It does heat up the back sleeping area pretty well and it
uses a very small amount of battery and propane. I am thinking of a drape
at the end of the bed to trap some of the heat and perhaps a small length
of the new aluminum coated 3 inch dryer vent hose to route the heat under
the covers in severe cold . With both mantles going on high the blower
fan will cycle on and off running for a few minutes to cool down the
heater then off for a few minutes as it heats back up.
>
>I have the corvair gas heater that I will be installing next that is a
bit of a heat monster. It draws a hefty 7.5 amps and blows out significant
heat to heat the whole van in several minutes. I am going to try to
incorporate a hot water coil to its exhaust for heating water in the tank.
>
>My thinking is use the gas heater for major heating and this propane unit
for low draw during the night.
>
>I have the GL back seat and access to the drivers side body cavity for
this, the westy has the closet there. I believe I could design this to
work as a free standing unit that could sit on top of the closed stove
sink lid and route the intake and exhaust to the side slider window for
fresh air heat. You would need to splice into the propane line behind the
fridge and hook it up after cooking etc but I think I could make a nice
unit that would work well and throw light to boot.
>
>What is once only a thought and notion in your head can become a reality.
>
>Pics:
>
>
>http://users.ca.astound.net/dougfayne/lanternheaterwideshot.JPG
>
>http://users.ca.astound.net/dougfayne/Lanternheatercloseup.JPG
>
>http://users.ca.astound.net/dougfayne/lanternheaterxposed.JPG
>
>http://users.ca.astound.net/dougfayne/lanternheaterplumbing.JPG
>
>http://users.ca.astound.net/dougfayne/nightimelight.JPG
>
>http://users.ca.astound.net/dougfayne/exhaustvent.JPG
>
>
>
>
>Cheers,
>
>Doug
>
>87 syncro conversion
>89 wolfy
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