** ORIGINALLY POSTED AT: http://www.thesamba.com/vw/forum/viewtopic.php?p=2757451#2757451 - check there for updates / discussion **
Even with my close-to-stock (aftermarket heat exchangers, insulated heat tube, more recently a bilge blower) heat hooked up, our end-of-winter trip to Myrtle Beach and Everybus in North Carolina last year was very, very cold. It didn't help that we drove through four record setting days, coldest temperatures for those areas in dates in over 25 years.
This year my interest in replacing the gas heater was piqued. I removed and sold my complete non-working BA6 last year for a very good price on Ebay. I thought about someday getting a more simple BN4. But then I came across Eberspacher's newer heaters, distributed in North America by Espar. Others on this forum have used them with success, as well as some similar modern heaters like the Mikuni and Webasto.
There is lots of info on their website here: www.espar.com and this is an example of what the modern heaters look like:
After finding out how much the gasoline variant of these heaters was new from local dealers I was pretty sure I wouldn't go ahead. The price was over $2000 with the necessary installation kit. The diesel versions are far more popular for obvious reasons - their main market is very hot right now - reducing idling of big rigs by installing their heaters for nightime heating.
I started watching Ebay auctions and found a brand new B3LC 3KW (12,000 BTU) gasoline heater for a reasonable price, including lots of extra installation parts. Apparently it was an R&D project to design a heat system for Bobcat. I had to pay shipping from Texas which is ironic because the Espar dealer is literally a mile away from my office in Mississauga, Ontario. Here's some of what came in the boxes:
Since I have a '76, I wanted to install it where the spare tire is stored, behind the drivers seat, with a duct coming out of the spare tire cover and one coming out under the drivers seat. My wife was dead-set against that and insisted that whatever we do not detract from the functionality or appearance of the bus. In short, she wanted it underneath, in place of the original BA6.
My camera crapped out as I was doing the installation, so I drew up some diagrams of the installation. It is mounted to a steel bracket, bolted into the frame under the bus. A return air supply was drilled under the rear seat and piped with 75mm ducting into the heater. The 90mm outlet was connected into a "Y" piece of sheet metal ducting which was connected into the main heat tube from front to rear. This provides recirculation of air from inside the bus to the front and rear heat outlets, along with the stock heat. To allow use while parked I put a one way dryer flapper in the main heat system to not allow the heat from the gas heater to escape through the engine. I insulated all ducting afterwards.
NOTE: I am not affiliated with German Supply. They are a great supplier and give out handy-dandy note pads, hence their logo below:
The only areas I had to cut the bus were to cut a 3.5" hole under the rear seat for return air (because I had previously removed the BA6 return air connection), and I had to modify the BA6 belly pan to accomodate the support bracket for the B3LC.
On a test drive yesterday, the outside temperature was about 0 Celcius (32 Farenheit) and it was hot enough inside we were sweating and had to dial the heat down to LOW! We are very happy!
One other note - I realized that some of my problem before was a leaky front air intake. My bus had its nose replaced a few years ago by the PO and he didn't properly seal around the intake. Some seam sealer took care of that and now we have no drafts!
The B3LC is hooked into my deep cycle so it can run while camping. It only draws a lot of amperage when it's first starting (because of the glow plug) so it could theroretically run many nights on one charge!
Here are some pictures of the finished installation:
These pics are the return air intake.
This is the 7-day timer/controller - A little overkill, but that's what came with the auction!
Here's the exhaust.
This is all you can see under the bus. The exhaust, combustion air intake, and fuel line. The metering pump is hidden in this picture, but is mounted on the outside of the frame rail.