cabin heater cores and framing questions

[the_experience03]

I ripped my heater cores and hoses out and then just looped the lines back in on each other right behind the driver's heater core. It's not elegant, but it worked and I still have somewhere to tap into for hydronic baseboard heat someday.

My interior bulkheads are screwed in on the top and the bottom with those little galvanized L-brackets. I think I used the 3 inches version. Each stud is held by 4, one on each side top and bottom, with the exception of the end stud that only has the inside ones so they weren't sticking out. I also tied them together with stringers that are toe-nailed in so the walls almost look like an "H" on the interior. I filled them with some 1 inch white rigid foam insulation I just had laying around so that they wouldn't be boomy and echoing and then sheet them with luan. They were plenty strong before the luan, but it added a lot of rigidity when I did that so I prefer to think of my walls as being of monocoque construction.

[the_experience03]

It may or may not work for you. Heating and cooling are not efficient processes and will require lots of power to do. That little heater that keeps your feet warm under your desk? While it probably has a rating of about 750 watts. That's 62.5 amps on the DC side or about 2 hours of runtime until you need to start recharging a pair of golf cart batteries. Will it be sufficient to heat the area you'd be in? I don't know. Will it run just fine when the engine is running? Of course! But if you're only going to use it when the engine is running you might as well bypass the middle man and tap into those heater lines. My plan is to eventually add hydronic baseboard heaters. I'm not sure if they will work real well, but they're cheap so.....

[Griff]

Originally Posted by bender477

We are planning on using shore power electric heat or kerosene when parked and a pair of these small amperage d.c heaters for the cab/defrost .

If that's the same unit as JC Whitney sells, save your money and look elsewhere. I got one of that style from JCW and it wasn't worth a tinker's cuss! I bought it to defrost the rear window of a small dodge and the most it put out was very tepid heat - never would clear / keep the back window defogged. Just my $.02.

[sportyrick]

If you want you can drill a large hole in a 2x4 about half way through (the 3 1/2" way), drill a smaller hole the rest of the way and put a 2" sheet metal screw through it and screw it to the sheet metal. That is one way to do it as well as many other ways, yes just screw right to the sheet metal, you don't need brackets.
As far as the underseat heaters, did you look at the BTU's on them? Mine are 80,000 BTU each and just one would heat a normal size house. You might think twice about tossing them and put one of them in a hidden area under something. I didn't think I would ever use one but installed one anyway "just in case". Well that just in case came around this year when I took the bus to Tulsa in Feb for my aunts 70th birthday and hauled 11 people down there. It was in the 30's and it worked real well for traveling down the road in cooler weather. Remember that a bus has lots of air leaks around the windows and doors plus the heat loss through the glass and steel so there has to be huge heaters to keep things warm in the winter.
I did stand mine up instead of laying down and the only thing you have to do is put an air bleed at the top to get the air out. Mine works just fine that way and takes up a lot less room. It will run you out when both fans are on high. sportyrick

[SeanF]

I was able to use the defrost and step heater to help keep the engine heat down while climbing some serious grades. Yes, it was hotter than stink in the bus, but the temp needle behaved for the most part.

HTH
Sean

[beekay]

I too found both of my heaters helped a lot last January driving to Atlantic City. My significant other, who is not the biggest fan of the bus, complained she was cold...until she stepped outside into the true cold. I tailgate as well with the bus and it is sooo much better to arrive with even a bit of heat inside. I am also looking to mount at least 1 of the heaters vertically to shrink its footprint. I don't know yet what I will do with the 2nd smaller heater, but if you anticipate even 40 deg temps, I would definitely keep 1 heater at a minimum. Otherwise you simply waste the engine heat.