So Tom Forhan says:
> 
> The instructions show, as a sample installation, the air inlet directly
> above the outlet. Since warm air rises, it would seem this would cause
> the heated air to get drawn back into the furnace. I'd rather see the
> inlet as far down toward the floor as possible, and the outlet above it.
> Another option would be to put the outlet near the center of the van,
> and have the inlet off to the right side, near the door. You only run
> hose from the furnace to the outlet, the inlet simply allows airflow
> into the area under the seat. 

I mounted the thermostat on the closet just below the level of the speaker
on the adjacent panel.  

I drilled the air inlet on the bench kick panel to where if you look on 
the inside, it's just above the computer box.  I didn't route a hose to
it as shown in the Propex diagram.  Since I wanted the heat outlet as
short as possible (heat transfers poorly), I put the hole in the kick
panel just between the aux. heater box cover and the Propex heater. 
This gave the shortest possible hose run to the heater outlet itself. 

> 
> >From the instructions, here is what you should either dig up in the
> basement, borrow from your unca', or go shopping for:
> 
> Power drill and your usual drill bits
> 
> Usual screw drivers
> 
> 1" hole saw, or 1" bit. For cutting through the floorpan
> for the combustion inlet and exhaust; it needs to be able to
> cut metal.

Uhhh... This should be a 1.5" hole saw.
> 
> 2" hole saw - for wood. This one is my suggestion for Westies, and not
> mentioned in the instructions. Propex shows the exhaust passing 
> through a metal floor, but in my Westie it will have to pass through
> the wood floor of the underseat compartment before going through
> the metal floorpan. I examined the exhaust pipe, and it is not double
> walled. So to insulate the wall of the exhaust pipe from the wood,
> I want to open up the wood portion of the hole through the floor
> so that it never touches the exhaust pipe. I'd like to hear opinions on
> this...

I just used the 1.5".  I don't think the exhaust will get hot enough to cause
problems with the wood.  I went to about 10 places to find the 1.5" metal
hole saw.

> 3 3/4"  hole saw: for cutting out the air inlet and outlet holes in the
> wood/laminate front face of the rear seat.  I suppose you could do this
> with that wobbly, jumpy hand-held jigsaw, but I'll just use my hole saw.
> Call around, I found this item at a wholesale plumbing supply store, my 
> fourth stop in the quest.

I found mine at a power tool outlet place.  Be sure that the hole saws come
with a center tap for a guide.  Forget using a jigsaw.

> 1/4 copper tubing. I got ten feet, probably twice as much as I need, but 
> it allows for one major error. 

Get a 20 foot one for when you do f**k up.

> Tubing cutting tool. The ones I like have cutting blades on both sides,
> and are called "minimum clearance" or something like that. They are
> designed for work in small, cramped spaces, like VW buses.
> 
> Silicon sealant. This is used for sealing the holes in the floor pan.

The heater should have come with this????  Mine did.  Maybe I ordered
it, but I don't remember doing so.

> (4) hook up the power to the aux battery system you installed last
> weekend  ;-). 

You should run, at least, a couple extra wires behind the fridge so 
that if you need more for other uses, then you don't have to pull the
fridge again.

Good Luck!

Steven