Has anyone connected a webasto like heater to the bus heater vents?

BRUISER · October 18, 2013, 12:25:35 PM

With the temps starting to drop it is time to figure out heat for the bus..

my onboard floor heat works great when driving down the road, to the point it will cook you out

My thought is to figure out how to plumb in a webasto or similar type heat system into the existing floor duct work so when camping I can use that.. and then I dont have to add more duct work..

any links to others build etc?

thanks

belfert · October 18, 2013, 01:18:12 PM

Could you just hook the Webasto to the engine cooling system? The bigger issue would be the amount of power required to run the large blower fans in the stock HVAC system.

sledhead · October 18, 2013, 01:39:25 PM

http://www.princessauto.com/pal/en/Auxillary-Heaters/24700-BTU-12V-Auxiliary-Heater/4240028.p

for instant heat I use this off of my proheat or off eng. heat when driving . dave

Jeremy · October 18, 2013, 02:45:45 PM

I'm not sure whether the original poster is asking about a hot air Webasto plumbed into the bus's ductwork, or a hot water Webasto plumbed into the bus's heat exchangers. My plan is to do as Belfert says and plumb the Webasto into the water system, with a two-way valve to enable it to either heat the bus or heat the engine.

On my bus the heat exchangers are located in the middle of the bus on either side, with air ductwork running the length of the bus. Unfortunately this ductwork was actually above the floor so has all been stripped out as part of the conversion - but I'm able to replicate a lot of it by building new ductwork under the cabinets and furniture on both sides of the bus - but this ducting won't reach into the rear bedroom, so I've bought an extra heat exchanger which I will eventually plumb into the system back there.

My OEM blower fans look like they are fairly efficient things by the way, although I've not tried measuring how much current they suck. There are four of them and they all have two speed settings, so they should be fairly flexible in use I think - but the big difference is that these fans are only for running the heat system - my bus never had air conditioning, and I can well imagine that AC fans are bigger and hungrier things in all respects

Jeremy

BRUISER · October 18, 2013, 06:39:55 PM

My thought is have a heating system setup with its own blower but just have it ducted into the bus floor duct work.

I know new RV have furnace systems on board and they are ducted. I was just hoping someone else has already tried using the existing duct work.

luvrbus · October 18, 2013, 07:37:33 PM

Factory bus heat has a fresh air intake for the floor vent because of the large blowers and heat exchanger that is something you would need to work out,I think small zones with low amp draw fans and heat exchangers would work better for you JMO

hargreaves · October 18, 2013, 10:33:36 PM

I took the main blower motors out and installed the 24 volt squirrel cage blowers from the overhead baggage racks. a lot less air movement and much less noise. I have a 105,000 btu webasto that heats the system up quickly. Draws about 14 amps . Cheers Gerry

Jeremy · October 19, 2013, 02:22:49 AM

Quote from: luvrbus on October 18, 2013, 07:37:33 PM
Factory bus heat has a fresh air intake for the floor vent because of the large blowers and heat exchanger that is something you would need to work out,I think small zones with low amp draw fans and heat exchangers would work better for you JMO

That's true, but I imagine most buses are like cars in that the heating system can be switched to either take fresh from outside or re-circulated air from the inside. That's why my bus has four fans in fact - there's two on the fresh air circuit and two on the re-circulated air circuit

I agree that having heating in separate zones may be better than having to heat the whole bus. For me it's too difficult to work out how to do that without building a new system from scratch, but I'll also have two or three local electric plinth fan heaters as well (when I find some at the right price - the ones I've seen so far seem really expensive for what they are)

Jeremy

luvrbus · October 19, 2013, 05:25:48 AM

Gerry seems to have worked it out but his 14 amp draw is not going to work for camping 14 amps is about what 1 roof top AC draws fwiw zoned heat is going to be the best for camping IMO

good luck

hargreaves · October 19, 2013, 07:50:59 AM

I agree Clifford, It works good if you are hooked up but not so well if you are boondocking. I have it hooked up to my thermostat so that going down the road it does its thing without the webasto coming on.

I am wondering how it will work if the generator cooling was hooked up to the heating system. Don't know if there will be enough heat from the genny .

Cheers Gerry

Paso One · October 19, 2013, 09:17:40 AM

Attached is a picture of my set-up. Since I live in the frozen north for 5 months of the year have a few heating options.
One is what you are asking sort of.....
The Webasto has a circuit to of coarse heat the engine, as well as a circuit to divert the hot water to a old "front" heater that directs the hot air into my bathroom if I so chose.
As I use a heat exchanger to heat my domestic hot water tank while driving down the road, this also can be diverted into the main circuit which also can be directed to the water to air heat exchanger. after parking.
(old front heater c/w blower yellow motor on left)

Oonrahnjay · October 19, 2013, 01:54:09 PM

Quote from: hargreaves on October 18, 2013, 10:33:36 PMI took the main blower motors out and installed the 24 volt squirrel cage blowers from the overhead baggage racks. a lot less air movement and much less noise. I have a 105,000 btu webasto that heats the system up quickly. Draws about 14 amps . Cheers Gerry

Gerry, what makes that current draw? I'm guessing the fuel pump/igniter (and other internal draws) in the Webasto unit itself, a hot water circulation pump, and the heat exchanger fans? How may blower fans? Have I got this right? Thanks, BH NC USA

hargreaves · October 19, 2013, 05:13:50 PM

Bruce, you have it exactly right. Only about 7 amps from the webasto including the circulating pump, the rest is from the two blower fans.

Cheers gerry

Homegrowndiesel · October 20, 2013, 04:06:23 PM

If you want low amp draw, so you can boondock for for an extended time,,,,, i have used radiant heat exchangers. No amps for blowers. Now pumping all of your heat thru the stock set up is going to lose alot of btu;s . Just depends on what you are trying to do. http://www.ebay.com/itm/Hydronic-Radiant-Heating-panel-radiator-12x40-/190932558145?pt=LH_DefaultDomain_0&hash=item2c7477a141 something like this in our bedroom has worked great for us. We all use our busses a little different.

Chuck Hancock · October 20, 2013, 07:40:18 PM

I have two Webasto's, one that is a four zone radient heat system that is a closed loop to heat the inside of the bus. The second Webasto's is a small unit that draws coolant from the engine, heats it and sends it through a transfer coil in the water heater and back to the engine. When boondocking this second small Webasto's gives me really hot water and preheats my engine to 110 degrees in about 30 minutes which helps with starting in cold weather.