Furnace size and quantity

[Tikvah]

I'm considering purchasing a Furnace.  Seems it should be installed early during the conversion process.

We're not warm weather people.  It won't be unusual to be camping or traveling in sub-freezing temperatures.

The 40' MCI will have significant insulation, but almost impossible to insulate up front.

What size do you recommend?   Do I need one unit, or two units.

[bevans6]

If you are thinking of RV type propane furnaces, I would get two 30Kbtu to 40Kbtu furnaces (I don't follow the current size offerings).  Mine is a Suburban.  I would install one behind the driver's seat in the bus,  not in a bay, and duct it to heat the entire forward living area of the bus.  I would install the second one towards the rear of the bus and duct it to heat the bedroom and bathroom area.  I would have separate thermostats.  I would not install them in the bays and try to duct under the floor - I have that in my bus and it is a major pain and doesn't work very well, too much heat loss and the cold air return is a total pain to figure out.

Others have great ideas about other systems, all I know about is propane furnaces since that's what I have!   

Brian

[luvrbus]

I have saw some neat hydronic systems built off the hot water heaters in RV's,there a drawing somewhere that shows how to do it

good luck

[buswarrior]

Since you are planning to camp in the cold, heat must be reliable.

I will second bevans6's suggestion for redundancy.

I'd rig it so that the rear one also had a simple duct out towards the front of the coach that may be blocked or not, so that it might with relative ease, be employed alone if the front one fails, or you want to even out your furnace hours.

The less drama required to compensate for equipment failure, the greater the enjoyment of the coach by everyone else.

Busnuts are notorious for drama, their spouses are long suffering.

Or not...

happy coaching!
buswarrior

[Tikvah]

I have saw some neat hydronic systems built off the hot water heaters in RV's,there a drawing somewhere that shows how to do it

My first intent was a hydronic system, but it seems complicated.  Maybe if I could see some drawings or pictures.  I'm a visual person... not an engineer.

Dave

[TomC]

When I was contemplating my heating system, I considered using an AquaHot hydronic heating system that will heat the bus, give you endless hot water for showers, have a loop for heating the engine, with electric standby.  That is until I found out the cost of the complete system-about $7,000.00!  Instead I have a single 36,000btu Atwood furnace mounted under my kitchen but above floor so to recirculate the air from the inside, rather then pulling in cold air from outside with 4 ducted vents from the back to the front.  It works well-have only been in down to 17 degree weather and at 17 degrees, runs about every 40 minutes (I have 2.25" of sprayed insulation).  The Atwood furnace is about $550.00 through J.C. Whitney.  For hot water I use two 10gal electric water heaters-those were about $500.00. For heating my engine I just put a 500watt halogen light under the oil pan the night before ($10.00).  And my propane tank was about $500.00.  So for about $1,600.00 I have my heating system, water heater and block heater.  And in the 17 years I've been using the bus, only the furnace has been replaced-and that was my mistake leaving the thermostat on for two weeks (the electric fan motor didn't like running for 2 weeks straight).  Ask anyone with a hydronic heat system how much maintenance is required to keep them working well. Good Luck, TomC

[TomC]

When hooked up to the power pole, we have two electric heaters (that's about 11,000btu/hr total) that under most circumstances will keep the inside warm and save propane.  Good Luck, TomC

[luvrbus]

Check out articles by Jim Phyper I have saw his design with a few improvements in the design and the hydronic heat worked good in the RV I was in they used a separate hot water heater the guy told me he had less than 500 buck in the system he made his own exchangers from from car heater cores and muffin fans super quite and he boondocks in the winter

good luck

[Bill B /bus]

Before we could get out during the cold months  I decided that we would need two furnaces. One for thew front end and one for the back. During the design phase for the first coach, as she looked over my shoulder at the drawing she said "What's that?"  I replied "Two furnaces. A big unit up front and a small one in back."  "Two jet engines?" she said. And followed with "Any other heaters?"
The next day I called Dick Lamb at Custom Land Yachts and asked him what my options were for heat. He said that he used the Aqua Hot system because it was only a day plus to install versus a week to install a complete Webasto system. I asked why the hot water system vice hot air. Dick said peace and quiet. Now on our second bus with the Webasto system. Maintenance is easy. Change the burner nozzle annually and clean out the fire tube. I have had to replace a fan motor after three years. Before we head to warm climates, after Christmas, we will use about 60-70 gallons of diesel to keep the coach heated.
Advantages of the hot water system: quiet, lots of heat, very little space lost to equipment, less volume for fuel supply tank.
Total cost of the Webasto, 9 heaters, hot water tank (electric and Webasto), 6 thermostats, two pumps ( one for engine preheat), heat exchanger for road heat, wiring etc was less than $3500. The Webasto and the generator have a seperate fuel tank of 55 gallons. That saves road tax when you can find off road fuel.

Bill

[skihor]

Our bus had one 44K in the back. I moved it up front and put in a 22K in the back. I also ran a duct from each unit into my "water" bay. All of our tanks and water supply lines, and drains are contained in the one bay. I've held water down to -16F before, without freezing.

Don & Sheila

[luvrbus]

QUITE with a diesel fired Webasto or Aqua Hot that is funny I don't care you are lol

good luck

[gus]

If you decide to go the hot water route I have a used Model X45, 45,000 btu ProHeat, about the same as a Webasto, for sale for $400 + shipping. I got it from Bruce Knee and realized I didn't have any use for it. It came from a semi truck-tractor.

[Lin]

I think of the hydronic systems as first class and expensive.  The RV furnaces, which are forced air, are a bit noisy, but no where near as loud as a rooftop AC.  They are probably about the most easy and trouble free.  The idea of two furnaces for redundancy is good, especially since you say you will be in situations that require heat much of the time.  I do not think that any of the hydronic systems offer that, so if the little thingamabob behind the framis gets clogged, you're in trouble.  We just have one furnace, but have an Olympic catalytic heater for back up.  I have had a Platinum Cat in storage for years and keep meaning to install it.  However, we have not done any cold weather boondocking, so electrical heaters have been fine.  Hence, my lack of motivation.

[belfert]

I originally bought and was going to install a propane furnace, but I quickly determined I didn't have room for the duct work or room for the propane tank required.  My interior layout is designed for 8 people so most of the space is consumed by seating or bunks.

I decided my only other choice was a diesel hydronic heater running off the main tank.

[artvonne]

  Im keeping my original OTR heat and AC. Want to slow down the main ventilation fan, 2 HP fan is WAY overkill, flipped it on the other day and with the heat runs gone there is a tornado going in there. Going to replace the original metal heat runs with wood runs and install vents where needed.

  Engine supplies heat while running. Parked? Thinking gas/electric water heater with heat loops from engine and genny as well as domestic hot water.

  Those Atwoods and Suburbans are pretty inefficient, both in heating as well as moving air. The blower motors in them are little and turning little fans = noise.