There are a few mentions above about Propex heaters. I have seen very little info about them and I know that they are hard to get. I finally bit the bullet and bought one. It replaces the catalytic heater mentioned in some of the above posts. It also replaces the webasto coolant heater that was installed in Canadian syncros. The Webasto was a great idea, but it was just too complicated and since it was an integral part of the cooling system, it added one more thing that could go wrong with the cooling system. It also drew a ton of amperage to run the coolant pump, the fan blowers etc.
The Propex is very elegant in it's design. I spent a lot of time trying to figure out where to install it. I had been told that most people install it under the rear seat, but I looked seriously at mounting it at the bottom of the closet, ducting through the food cabinets, and out by the edge of the seat. I also looked at installing it in the cabinet to the right of the fridge. I finaly settled on under the back seat as suggested.
I bought it from Van-cafe (Nee volkscafe) It was advertised as having simple install instructions. Be advised that the instructions are very generic, not westy specific.
The basic install is very simple. There are two 1" diameter pipes, one for intake air, one for exaust, a gas line hookup and t-stat wires.
Once I decided to use the under the seat space, I spend a bunch of time calculating where to place it so that the vent pipes would clear frame rails etc under the floor, and how the warm air outlet would work. I installed the heater on the passenger side of the seat box, with the warm air outlet pointing toward the center of the car. The 3" diameter flex pipe then turns 90 degrees and connects to a fitting cut in the seat front. The cold air return for the heater is another grill cut in the seat front. The heater itself needs 25mm (1") of clearance around it for the air to circulate. The heater sits about centered front to back in the box. Intuitively you would be tempted to put all the way forward or all the way back. Be careful, if you put it all the way back, the vent pipes run into the rear swing arm frame rail. I couldn't but it all the way forward (save the 1" clearance) because I have a tool box mounted under the floor that I had to clear.
The gas line is 1/4" copper, although the instructions call it 5/16". (More on that later) I ran the copper under the rear seat heater, then into the side cabinets under the ciruit breaker/outlet boxes. (I discovered a new hidey hole for stuff here. The space between the lower cabinet and the water tank is blank. You can accsess it by pulling up the bottom of the upper locker. There is even a pull hole drilled in the bottom of the locker!) From there, under the fridge into the cabinet to the right of the fridge, with a joint in the left hand cabinet to make it easier to get under the fridge. I already had a tee in the propane line above the shelf in that cabinet. I used this tee to tap in.
The heater comes with a 1/4" compression fitting to connect the gas line. Compression fittings are NOT acceptable for gas line work in North America. I used the supplied fitting for the first section of the pipe, and all the remaining fittings are flare fittings that are acceptable for gas line work. Also note that the british supplied compression ferral is NOT the same as the US counter part. I suggest that you connect to the heater once with this fitting, and then put a gas line shut off valve next to the heater. When you have to take the heater apart, take it apart at the valve, not the heater, because once you tighten a compression ferral, you should never reuse it, especialy with gas! All the gas fittings were then tested with a spray soulution to make sure there were no leaks.
I mounted the t-stat on the closet wall, running the wire in through the cabinets. The twelve volts I picked up from the 12volt source in the cabinet to the right of the sink.
The exaust and intake flex pipes clamp on under the car and are strapped to the side. After test running, I made a cover out of birch plywood that sits over the heater so that you can still use most of the area for storeage. You need to leave 1" above the hater for cirulation, so the new cover sits on cleats 1" above the heater. You end up loosing 5 1/4" of space under the seat from the passenger side to the seat heater.
All in all it works great. It draws 1.6 amps, and puts out 1800 watts of heat. It is a bit noisy but it warms the cabin very quickly. Because it is vented and draws it's combustion air from outside, you can safely sleep with it on. It also cuts down on the condensation inside. You lose a bit of space under the seat, but if you are carrying a catalytic heater you more than make up for it by not having to carry it.
I'll post after a winter of ski area parking and cross country treks.
Icarus
PS The unit burns propane at a rate of 128 grams per hour. The 2.4 gallon net gallons in the propane tank yields about 4500grams+- leaving a run time of about 35 hours. This is not taking into account any use of the fridge or stove however.
PPS. In a test this morning, turning the unit on, it raised the cabin temp from 25f to 60f in about 10 minutes. Not bad for 1.5 amps 125 gram per hour!
PPPS. Update a few months later. I just did an installof a Propex for my Mechanic's Syncro. Installation was similar to my own with the exception of the gas piping. He already had a tee in his line, at the tank to fuel a catalytic. He had a rubber hose that was just hanging under the car. I removed the rubber, replaced it with copper ran the line back along the frame rail, entering the under seat area through a grommet in the floor. Much easier to run the line this way. I don't know how hard it was to tee the line at the tank since I didn't do it. (I had teed mine under the sink earlier for a catalytic.)
Once again it works great and he is very happy with it. I have used mine all winter for ski area parking and I love it. It is great to come in for lunch, fire up the stove for tea or soup, crank the propex and have instant heat. It is also great for drying out wet gear since the hot air volume is so high. Running it for several hours has never left my battery indicator in the yellow. (It runs in the yellow and returns to green when it shuts off.)
Hands down the best choice, (in my mind!) for aux heat. They are spendy to buy, but for what it give you there is no subsitude. It is too bad that none of the American manufacturers have figured out how to make something this small and elegant. All the atwoods and other brands are too big to fit in the cabinets.
Icarus