OTR heat if you remove the bus system ?

[someguy]

Are people aware of the affordable Chinese 2 and 5 KW diesel fired air heaters ?  Van people love them.   There are also Chinese clone 5 KW diesel fired water heaters.

I'll be putting hydronic heat in the floor of my conversion.  I'm thinking 5KW hydronic plus 2 x 5 KW diesel fired air heaters should keep it very warm when stationary.  Still trying to figure out the OTR solution.

If the bus I buy has a 90K BTU engine heater, that changes everything.  I'm focusing on buses that lived in the south, so ?

The problem with propane Buddy burners is they release moisture and CO2 into the air in the bus. 

[someguy]

I don't think any of the Webasto heaters are 90K BTU.

https://www.webasto-comfort.com/int/product-overview/#!Bus/Heating/Water_Heaters

Until recently the largest was the Thermo Pro 90, which is 9 KW or about 30,000 BTU.

[buswarrior]

Look at DBW models of Webasto and Proheat X45 were also popular.

You get what you pay for... better have CO monitor in the coach for when that knock-off heater cracks its heat exchanger and tries to poison you.

A big DBW 300 plumbed in-line to the stock heat exchanger, and the stock blowers being run on a bypass, takes about 11 amps of 120v AC fed to a Trace 4024 connected to the batteries.

A Yamaha 3k generator will quietly purr all night keeping the coach as warm as you dare to set the temp.

No cold spots, heat right out of the walls, no condensation, fresh air intake, and the engine will light off like a summer's day.

Happy coaching!
Buswarrior

[sledhead]

yup

diesel boiler to heat coolant to cozy fan heater = warmmmmm

https://www.busesandmore.com/inventory/new-proheat-x45-24-volt-coolant-heaters/

https://photos.app.goo.gl/4uJ4ybsbVNpTUydT9

https://photos.app.goo.gl/CuTKNjr4XfQrFEaF9

to kick space cozy heaters under kitchen cabinets and in many other areas through out the coach

https://photos.app.goo.gl/dJb1mgHng9ngVByp9

dave

[Jim Blackwood]

The Webasto website is not the easiest to navigate, but if you have the model number you can find it. Same for Eiberspacher.

Think of the system as 3 big loops. The aux heater loop, the coach loop and the engine loop. There are valves to isolate the coach loop from the engine loop. What is needed for RV use is valving to isolate the engine and allow flow between the aux and coach loops. You shouldn't have any trouble figuring out how to do that. Dead simple compared to CAN bus.

On the AC, the MCI has two 1.5 Ton evaps in the bin rack and a 1 ton in the dash so all that's needed to get 3-4 tons is a shutoff on the main evap. Run the sealed compressors on AC.

The rear bay of the DL has room for about 400-500 gallons for fluid and still be able to swing up the HVAC door. How you apportion that would be up to the owner. Other models will be different.

Jim

[thomasinnv]

I don't think any of the Webasto heaters are 90K BTU.

https://www.webasto-comfort.com/int/product-overview/#!Bus/Heating/Water_Heaters

Until recently the largest was the Thermo Pro 90, which is 9 KW or about 30,000 BTU.

The DBW 2010 is 45k, 2020 is 80k, and 300 is 104k...all of which have been around for quite some time now.

[someguy]

Thanks.

[TomC]

I got rid of all the central heating system. I kept the heater core, had it pressure tested, and mounted it lengthwise under my washer and closet in the hallway. I have 2-14" 12v radiator fans on it, and a ball valve to shut it off in summer. The thermostat is by the driver's seat. When it kicks on, I can count to 10 and then feel the heat in the driver's seat. Works incredibly well. I also have three roof A/C's with heating strips, 35,000btu propane furnace and two electric space heaters-which is what we use when at the power pole. Good Luck, TomC

[luvrbus]

I have 3 heat pump roof tops and the 600 Aqua Hot 65.000 btu in a 45 ft coach the floor heat alone 58 degrees kept it nice and warm in the New Mexico winter last year,I never turned 1 zone on just the floor heat,be prepared the diesel fired burners will suck some fuel in 24 hrs like 3 to 4 gals a day for a Aqua Hot with on demand hot water   

[someguy]

How efficient is a Aqua Hot ?  3 to 4 gallons of diesel fuel a day is a lot.

How is one supposed to heat a bus when boondocking ?  Last time I was in California, propane was expensive and hard to find.

Rinnai 75K BTU Boiler/Tankless water heater, propane.  $2154.  95.5% efficient.  Weighs 91 pounds.  Has a recirculation pump built in.   All one would need are some zone valves.

https://www.homedepot.com/p/Rinnai-E-Series-Propane-Condensing-Boiler-Tankless-Water-Heater-with-75-000-BTU-Input-E75CRP/306698776?MERCH=REC-_-plpbrowse_multi-_-NA-_-306698776-_-N

Run the whole coach on propane ?  Cooking, heat, water heater, engine heater via a heat exchanger.

90K BTU model.  64 pounds.  Standby 3.5W.  Running 177 Watts.  Cheaper than a Aquahot.  $2350.

https://images.homedepot-static.com/catalog/pdfImages/35/3537cefc-5eb3-4a5c-8831-51d60840863f.pdf

Apparently one can use a tankless hot water heater, which is a bit less expensive, for radiant heat.  But then you need a heat exchanger to get hot water from it and its more complicated.   And tankless hot water heaters aren't designed to be boilers.
https://www.jlconline.com/how-to/plumbing/heating-a-home-with-a-tankless-water-heater_o

My last house had radiant heat.  I'm familiar with some of this.

[someguy]

180,000 BTU Rheem propane combi boiler.   Would do hot water, house heat and engine heat. $1759.  95% efficient.  Draws 180 watts, including the circulation pump when running.   15+ amps from 12 volts.
https://images.homedepot-static.com/catalog/pdfImages/7e/7ec3ea00-658b-4e43-80e3-bfc5fe7a90ae.pdf

FYI 10 Gallon RV hot water heaters are 70% efficient and 10K BTU.   $850.

Wouldn't take long to heat up the bus and/or engine with 180,000 BTUs.

[sledhead]

I looked at doing this but you would need a good size propane tank

" Rinnai 75K BTU Boiler/Tankless water heater, propane.  $2154.  95.5% efficient.  Weighs 91 pounds.  Has a recirculation pump built in.   All one would need are some zone valves.  "

the diesel boilers are crap when it comes to efficiency maybe 55-60 % and never touch the exhaust pipe as it will burn the skin off you   but I have a 190 gal. diesel tank and when on the road it is real easy to fill up the tank unlike trying to find a propane station that you can get into 

I had a in floor hydronic heat system on the M C I that worked great when driving but when camped it took to long for the heat to get through the floor even with the metal heat plates under the 1/2 " pex pipe in the floor .
the cozy heaters are almost instant heat when you want it but yes there is the noise of the muffin fans

https://www.parts.rvhydronicheaterrepair.com/Heat-Exchanger-Cozy-III-EXE-103-0EX-Non-Stock-Item-EXE-103-0EX.htm

dave

[richard5933]

How is one supposed to heat a bus when boondocking ?  Last time I was in California, propane was expensive and hard to find....

...Apparently one can use a tankless hot water heater, which is a bit less expensive, for radiant heat...

I think that this is the problem many run into - realizing that while there are many options none of them are free and/or easy.

Yes - whatever you choose to do to heat and cool a bus it's going to consume fuel and cost. Solar & lithium setups are starting to be more able to handle HVAC functions, but they come at a price.

Tankless water heaters are great at saving fuel for making hot water, but they do it at the expense of consuming more water.

Everything on a bus conversion is a tradeoff. Weight, cost, fuel consumption, style, availability, convenience, etc. all have to be balanced in nearly every decision as systems are designed and installed.

And, if propane (or any type of fuel) is difficult to find or expensive in one location, get it somewhere else or choose a different fuel. Around here (and most places) propane is reasonably priced and widely available. If there's a warehouse anywhere near you, odds are they are getting their propane tanks filled in the area.

[dtcerrato]

I know this is Neanderthal but going to throw it out there anyway... Wood fired heat is feasible & actually is synonymous with boon-docking. We thought it was far fetched (in the RV world) until spending time boon-docking in outlying areas in the great white north. Most successful GWN boon-dockers always incorporate at least 3 of four types of heat, that is: fuel oil, propane, electric, or wood. With some ingenuity and copper stilling techniques heat from a wood stove can be utilized in numerous ways. Many GWN RV's had wood stove chimneys on them. On our Camp Malemute in Tok Alaska wifey & I have been toying around with the idea of trying a winter there in the bus. Why not? Full hook ups including 50 amp RV plug in - that would cover the electric heat. 4 portable 30 lb. LP tanks on board with two stand-up 100 lb. LP tanks back-up for redundant on board propane furnaces. 200 gal. fuel oil tank and vintage 50,000 btu Sears oil burning furnace. So that covers 3 of the 4 heat sources. Then there's the true reliable back up - a vintage Jotul 602 wood stove. What could possibly go wrong to leave you completely out in the cold? Oh forgot to mention the neighbor has a small guest house as an emergency get away & fuel stations / fuel delivery is within a mile or 2 away... Crazy but thinkin' 'bout it... Just thinking out loud, carry on

[windtrader]

2cents free.
I see radiant floors as an option and it's a fine idea for home heating during a cold season or two. In a bus, there is far more intermittent use, maybe even daily, and in general radiant flooring takes 100% to get warned up and more time to get to temperature. It seems only worthwhile if that heat is going to be constantly on. Now, maybe with careful selection of materials and design, a radiant floor system can be constructed to minimize thermal mass so the coach heats up faster and use less energy.


Likewise on inside stoves. If properly chosen, look to mariners, it can be safe, aesthetically pleasing and comforting. Central systems are easy to use, low maintenance, and ease of supplying fuel source, just the opposite for wood.


Finally, with solar and lithium now able to run a bus fully offered, electrical heat is worth revisiting. Combined with mini-split for heating and cooling and occasional use of space heating, this may be the best configuration today. Those small radiant heaters throw instant heat that nothing else will match for speed or convenience. There are many times when you just need to knock off the chill for a bit, taking shower, getting in/out of bed. Once you're dressed you're on your way. Heat and go.