I guess I started this thread and the truth is I am not happy at = all with the performance of my coleman black cat. I go Skiing and ice = climbing in the winter and arrive at my destinations very late at night. This = heater can not keep up for the cold that I encounter. However it was affordable,and I had read good things about it. I would gladly = pay a couple of hundred dollars for a good ventilated system that would fit = in a vanagon. Looking on RV sites I have not found a system under $400, and = even at that they are to big to fit reasonably behind the front passenger seat = and still have room(I have 2 dogs and a wife that crash in there = too.). So anyone that has found a good system PLEASE let me know. I am willing = to install a propane tank and/ or aux. battery (plan too anyways). = Thank for the propane education!

Randy Charrette

87' Syncro weekender

Longmont, CO

>From: Dennis Haynes

>Reply-To: Dennis Haynes

>To: vanagon@GERRY.VANAGON.COM

>Subject: Propane pressure facts

>Date: Thu, 1 Nov 2001 20:54:47 -0500

>There has been a lot of talk about the use of propane = heaters these past

>few days so I though I would clear the air!

>The pressure in the propane tank is a function of the = propane and

>temperature. As long as there is liquid in the tank, = the pressure will

>be close to that stated in the chart.

>http://www.gasplants.com/property.htm A bulk tank and = portable cylinder

>will have the same pressure at the same temperature. = Note that propane

>and butane are great for carrying in small containers = because they

>compress to a liquid easily. The latent heat of = vaporization explains

>why a propane tank gets cold as the gas is being used. = Yes, heat has to

>be absorbed in order to create the vapor you burn to = make heat. Yes the

>relatively low pressure needed to compress to a liquid = also makes it

>possible to use as a refrigerant.

>Most propane appliances need the vapor pressure reduced = to 11" water

>column pressure. This is the job of the regulator. = Appliances designed

>to work with portable cylinders rely on an orifice to = limit the flow,

>thus reducing the pressure during use to a level = appropriate for the

>device. The major advantage of propane as compared to = other fuels is

>it's extremely wide flammability range. Air fuel = mixture is not critical

>for a clean burn. The down side here is that any = propane out of control,

>(a leak), presents a real hazard since the vapor is = easy to ignite and

>reducing the oxygen supply will not extinguish it. You = would never see

>an electric pump placed inside a propane tank like we frequently see in

>gasoline tank. Yes. The pump in the gas tank relies on = the fact that

>there is little oxygen so there is little chance of = ignition. Another

>problem with a propane fire is the fact that the tank = is already under

>pressure. As the tank is heated in a fire, the vapor = pressure will rise

>rapidly, especially as the propane tries to boil. This = can cause a

>BLEVE, (Boiling Liquid Expanding Vapor Explosion).

>Using a non vented heater in a Vanagon is not very = smart. I did this

>many years ago and now consider myself lucky. These = heaters need proper

>ventilation to ensure a safe oxygen supply for you and = to ensure no CO2

>accumulates. I believe the recommendation is two 12" X = 12" openings for

>each 5,000 Btu. One opening high, one low. Not much is = going to remain.

>Remember, most of these things are designed for tents. = If you must use

>these, get a good propane alarm and CO2 alarm and mount = according to the

>directions. You should also make sure the heater has = low oxygen cut off.

>Do not rely on the battery operated units. Go to an RV = supply and get

>the permanently installed 12 volt models.

>All combustion produces water vapor as a by product. In = the winter this

>will accumulate behind the interior panels of the van = and never dry out.

>It will even get inside the square tubes in the sides = and roof of the

>vans. My 1970 van rusted in places I never though = possible in only 2

>years of occasional camping this way.

>If you really need to add heat your van, you should go = with a

>permanently installed, vented heater. Do it right. It = is your life at

>stake here. As for connecting the portable heaters to a = bulk cylinder, a

>good RV supply can get you the needed fittings and = adapters. Marshall

>Brass makes a great T that goes between the tank valve = and the

>regulator. (Extend a Stay).

>Last spring, I posted a line of portable heaters that = stayed outside and

>used a 3" hose to pipe in the heat. I forgot what brand = they were. I'll

>look some more and repost when I find it.

>Hope some of this helpful. Remember, be very careful = suing propane and

>these portable heaters. It only takes one mistake or = unknown situation

>to make a disaster.

>Dennis