The down and dirty of coach heat

[Scott & Heather]

Heather and I have some pretty serious cold weather full timing experience with our record low temp full timing in the bus reaching minus 28 degrees F. Coupled with several feet of snow on and around the bus during various winters we have some fun memories for sure. That being said, in almost 5 years of FT, we are really needing to hone in on proper coach heat. Here's my take so far:

1. Propane furnace. We just recently bought a used unit that worked perfectly for a couple of weeks, then it decided to run rich one night, filled the coach with soot and smoke and freaked us all out (I have a baby now). It could be a multitude of things (dirty orifice, control board, etc) so I am going to yank it and call it $ down the drain. I honestly don't trust rv furnaces after reading the rv boards it isn't common to read about similar stories.

2. Electric space heaters can only do so much. Plus when you are rubbing off of genny power, who wants to use up their genny watts for three space heaters? Not me. We've been doing it since the furnace puked and I hate it. Gennies could run 20 hours running the fridge, pump, lights, microwave etc. But with two or three space heaters running, it's like 8-10 hours. It's been getting down to the low 20's with 30mph winds here lately.

3. Everything I read about webasto or proheat diesel heaters, they are a little bit pricey to maintain and sometimes quirky.

Hydronic heat seems to be the safe option with the combustion etc all happening outside your living space with relatively harmless hot water rubbing through interior radiators. I'm intrigued by this. But again, we are back to proheat or webasto coolant heaters which are $$$ to buy and maintain. Has anyone utilized a 30,000 btu stubby water heater (gas) for hydronic heating? Do they even make one? Any less expensive options for hydronic heat while parked in cold climates?


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[chessie4905]

How could it put soot and smoke into the coach? Hole in combustion chamber? We had one in our 4104 and it worked for years with few minor issues; spider web in intake, bearings getting noisy in blower motor after many hundred hours of use. It was non electronic model Suburban 30,000 btu. I think they are the most trouble free next to electric. Jmo though.

[skihor]

The usual culprit is a wasp, mud dauber nest in the exhaust port. The flame is contained inside a "box", and the fan blows around the "box" to provide the hot air. Soot and smoke sound like a compromised box. The first thing you need is a Carbon monoxide detector. We live in Denver and use the furnace a lot. Other than an occasional motor replacement no issues in 11 years. We have 2, a 40K in the middle and a 22K in back. I ran 1 duct from each into the water bay and can keep running water down to -16F so far. Hydronic heat is IMHO the best  and most even heat. In a bus it's a tough deal to build an efficient system.

[Scott & Heather]

I'm sure the box is compromised at some level. I can hear rust flakes rattling around in there. I could by a new unit and someday it's box could rust and leak fumes or soot into my coach again while I'm sleeping. Not ok with that risk after what happened to me that night. Again, factory RV's have had this issue too based on my reviews of other forums. One guy had his CO detector go off when his factory installed furnace ran rich. We do have a CO detector but CO hadn't reached critical levels to set it off but the sooty smoky air was plenty nasty. Honestly, I just have never been impressed with any of the "RV industry" stuff. I don't think they made stuff for fulltime use and I've had much better performance from house products. Anyway, what about building a hot water heater hydronic system?


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[buswarrior]

Good thread!

It looks like you are using the coach further north. Many busnuts only need heat to take the evening chill off...

Approach your challenge in a phased manner?

Efficiency/economy needs to be kept in mind when full timing, weekend camping can afford to be casual about these matters.

A combination of radiant and fan forced, plumbing a water cooled generator into the system to scavenge it's wasted heat... tie in domestic hot water heating, some rig the hot water tank to work both ways, as a receiver and a maker of heat for the system, redundancy or layering to get your harshest BTU total...

Design for quiet for light heating, count on the generator/power pole being involved for high heating needs.

Over-build the "air trapping" features... gurgling pipes in the middle of an otherwise quiet night can be maddening!

Webasto and Proheat only suffer preventive maintenance problems - peeps buy worn out ones, don't do the regular or catch-up maintenance aand then blame the machine...

Yes, they are a maintenance item, they have nasty job, and do a lot of "work".

For fun, have you looked at the equipment that the marine folks have available? Dickinson is one name.

happy coaching!
buswarrior

[Oonrahnjay]

... Anyway, what about building a hot water heater hydronic system?  

   Limited power/heat output.  A "small" household 120V heater (not sure about propane but don't see a lot of difference) uses a 1500W element.  If you're 100% efficient, that would put 5000 - 5500 Btu into your interior heated area.  A medium sized RV propane heater puts out about 40K Btu and those are marginal is some conditions.
   I've seen 240V electric water heaters with 3000 or 5000W ratings but those I've seen are physically very large (the size of a file cabinet, roughly) and they'd still only give you 10K Btu/15K Btu (roughly).
   Maybe there's an unusual spec'd heater (small in size, putting out 30-40K Btu) but that would be a big power draw.
   It would be worth looking at propane water heaters - they have good efficiencies these days, have good startup and "recovery" time, and may be small-sized.  But it doesn't seem to me that this would be a very good road to go down.  (I welcome input from someone who has looked more deeply into this.)
   Does ProHeat or Webasto make a propane unit?

[Rick 74 MC-8]

I thought about it but never followed through teheke (sp) makes a tankless water heater that can be used as a small boiler. I would think it could be converted to propane.

Rick

[Tikvah]

Scott, like you we have spent much time in Michigan and northern States during cold weather.  We haven't been in sub-0 temps yet, but we often wished were were not forced out of an area simply because of the cold.  Often we wish we could stay north and can't.

We have found our biggest problem is not producing the heat but keeping the heat in.  We have spray-foam insulation so our walls and ceiling are very well insulated.  But our problem is our windows (single pane) and vents.  Our frustration is always that all our heat seems to be lost to the huge amount of glass up front. 

I know, if I had deep pockets, I could buy double pane windows for the sides, but that doesn't help the windshield and non-insulated front area of the bus.  Our four ceiling fantastic vents condensate and surely release a lot of heat.  We have purchased the 14" square "pillows" for each and they help a lot.

As you know, we have a mini-split unit up front, above the windshield.  That heats very well, down to a point.  When we need more than the mini-split can produce we add electric heat, or gas heat if we have limited electric. 

I believe, if I could eliminate the huge heat loss out the glass, I could heat easily with my mini-split and gas.  But, I'm not willing to cover my windows and live in a dark cave.  So, south is my direction each winter.  We're in TN this winter, and being mild so far we're doing fine. 

If I could build anything more, I would add a marine style gas water heater and put a circulation pump through a heat exchanger with a fan through my floor duct system.  I would pump most of the heat to the front where the heat is lost. 
Also I would replace all my side windows with double pane $$$$ if I could.   
Then I believe I could winter north.  I would use a full combination of the heating systems.

Dave

[TomC]

It sounds to me like your using a propane catalytic heater that has combustion inside the bus. I can't see the reasoning for hydronic heat and all the maintenance they need. I have a 40,000btu Atwood ducted in my bus that works well. I replaced it after 15 years of trouble free operation when I left it run for 2 weeks straight. I could have just replaced the blower motor, but I wanted the updated version with quieter blower.
Now on my truck I'm using the big Suburban (20 x 12 x 12) 40,000btu with 4 outlets on my truck, but mounted in the basement with return air coming from the inside of the bus. I'm convinced that propane heat with RV style furnaces are the most cost effective, trouble free way to go. Both my truck and bus only have the stove and furnace running on propane with a cutoff solenoid mounted on the tank.
Re examine the propane furnace using 4 ducted outlets. Good Luck, TomC

[eagle19952]

how much time "off the pole" do you spend in sub freezing temps... if any, why ?

[Tikvah]

how much time "off the pole" do you spend in sub freezing temps... if any, why ?

For us, we like to move when we can.  So Walmart parking lots and places like that are rather common.  When it gets real cold our options are more limited.  We have a big battery bank with inverter, but even with that electric heat will be cut short.  The gas heat is the ideal option then.  I can run fans, and pumps for lots of hours.  But even the heat pump limiting.

With more mild weather we will still use our mini-split (heat pump) in cool or warm weather to keep us comfortable overnight and the inverter/batteries are fine.  It runs very efficiently and will keep us comfortable all night, but if it gets down into the 30s or up into the 80s we need more options.

[luvrbus]

ProPex,Alde (Primus) and others sell propane boilers even AquaHot and Hurricane have a propane system.I had Primus for years it was the best system I ever had it cheap to use and quite no helicopter sounds at 2:00 am like the diesel fired system   

[Lee Bradley]

re: Tom's comment, I just added a propane detector/shut-off system.  It has two replaceable detectors, a shut-off solenoid and control unit. You can use the control unit to turn propane on and off from inside the bus and if either detector detects propane and alarm sounds and the propane is shut off. I have one detector in the basement and one in the kitchen.  This is a marine unit and boats are quite critical of propane leaks. 
http://www.suremarineservice.com/S-2A.aspx

[Cary and Don]

Before buying a propane hydronic system, check out the Technomadia blog post. They had one installed this summer and loved it until they started using heat.  It seems it sucks down something like 30 gallons a week. They are in Arizona, not that cold there.

Cary

[buswarrior]

There is no way around burning a fuel of some type when it is properly cold.

The choice is which fuel to use, and in which system, when you need that 40 000 to 60 000 btu to get warm. As you noted, lots of glass needs lots of heat. I agree, covering the windows in blankets defeats the whole purpose of being a busnut.

Back a bunch of years ago, I did some half assed cold weather experiments with my MC8 and some electric heaters, coach was stone cold, taking temp measurements along the way.

IIRC, I posted it up either/or/and here or on BNO?

The generator can fulfill both a winter and a summer "maximum performance" role.

Heat strips in roof airs are useless in these conditions, don't even bother, and certainly don't count them in your BTU arsenal. Better to make up covers like the roof vents, heat loss up there is significant.

Don't fool around, if dealing with 0 Fahrenheit and below, your heating arsenal has to add up to a big enough BTU or you will be sad, and cold.

happy coaching!
buswarrior