The other thread on winters got me wondering. Has anyone just plumbed a webasto heater into the normal coolant line and , or maybe easier, used a secondary heat exchanger in the same heater core compartment to get that space warm and then to use the OTR blower to circulate warm air? like a normal home forced air system?
I left my returns intact and recreated the original side vents along the sides. Seems like the simplest way. I'd love an aquahot, but even a refurb unit / used unit is $3-4k .
Other than insulating around the vents some , I think the real hurdle here is a seperate speed controller for that beast of a motor. Which to be honest I wouldn't mind anyway when going don the road... just to dial the fan speed down sometimes.
So anyone even gone here?
Might work when you're plugged in. That OTR HVAC fan draws lots of power, so I don't know that it would be efficient for use off batteries though. Our Webasto on our 4106 used some low-current 12v blowers to move air through the heat exchangers. We could have gone for days with our Webasto on 12v compared to maybe a few hours trying to power the big fans in the HVAC system.
You'd also have to find some way to isolate the engine from the system when you're camping, as the engine would be a huge heat sink that served to suck all the heat out of the system and send it out the back of the bus into the atmosphere.
Our Webasto did have a connection to the bus coolant loop. This was used only when we wanted to use the Webasto to pre-heat the bus engine. At all other times there were valves to keep the hot coolant where we wanted it, inside the Webasto loop serving the interior heat exchangers.
Another thought is that sometimes it's nice to have redundant systems. One day you might have a leak in the OTR system and have need to temporarily shut the valves bringing coolant forward from the engine bay. With the Webasto system you'd at least still be able to keep warm while driving.
Well mid post there above, I think I realized having a redundant system would be best. but still using the same blower.
I found a reasonably price webasto (heater only for $500) , I was thinking. What if I find a radiator or two to put in the same heater bay. So two systems for heat generation, but one for air circulation.
I've been trying to find out the amperage draw for the blower. I'm thinking I could find a newer brushless motor or something that might be better on power.
You found a Webasto for $500????
Personally, I would never isolate the engine, and I dont.
https://minneapolis.craigslist.org/hnp/for/d/webasto-thermo-top-w-diesel/6673883010.html
You must be talking about heating a bay then?
Quote from: neoneddy on September 06, 2018, 11:11:19 AM
https://minneapolis.craigslist.org/hnp/for/d/webasto-thermo-top-w-diesel/6673883010.html
Nice boiler I have one. Makes up to 17,000 btu. I use it to for floor hydoric and five toe kick heater does ok here in Pacific NW.
Isn't that Webasto intended for pre-heating an engine? Will it produce enough BTUs to do much in the way of heating a bus to make it worth the effort?
The 2010 units like we had in the 4106 make about 45K, much more than the Thermo Top.
Quote from: richard5933 on September 06, 2018, 03:42:35 PM
Isn't that Webasto intended for pre-heating an engine? Will it produce enough BTUs to do much in the way of heating a bus to make it worth the effort?
The 2010 units like we had in the 4106 make about 45K, much more than the Thermo Top.
Yes they are - I bought one for my bus and then sold it again and bought a much bigger Webasto instead when I realised that the Thermo Top was way too small for anything other than what it's designed for, which is preheating car engines. In fact ironically I now the same heater again because there's one on my diesel Range Rover. They come as OEM equipment on many different car models, which is why Ebay is full of them. I dare say they'd do a decent job of heating the interior of a VW microbus or something, but I think you'd be disappointed using them in anything bigger.
Jeremy
Yes, you can plumb. A big Webasto into the lines heading forward to the stock HVAC system.
Efficiencies aside, it works just like the coach does going down the road, including lots of fresh outside air.
My MC8 was a mobile classroom in its earlier life. A DBW 300 webasto in the middle bay, plumbed into the forward flow pipe. A little bypass wiring and a switch, and the coach blowers and the temp control all worked as designed.
Of coursen you need to have a healthy 24 volt power source to keep those big fans blowing, but it's cold out...
The engine and its cooling system provides a handy expansion tank function.
For the weekend busnut, you can "waste" a lot of heat before all the valves and hoops get paid for, in efforts to be efficient.
For a full timer, this system would NOT be easy on the wallet...
But, my coach would stay warm inside, at a high price, anywhere on this continent...
Many efficiency pursuits never pay for themselves, when busnuts and internet forums collide...
Happy coaching!
Buswarrior
And, all your 4 stroke highway coaches already come with a hydronic boiler as part of the original equipment...
Already bought and paid for, and plumbed in someplace...
Happy coaching!
Buswarrior
I use a 45,000 BTU diesel Webasto, and it makes cozy heating when routed into the loop for the driver's heat. The system includes the water heater, two box heaters, and the driver's heat. All run by a wall thermostat. If I want the engine pre-heated, I just turn on the loop to the engine.
Our conversion maintained the OTR heating & ventilation system, we removed all the AC portion (dedicated 4 cyl gas engine, 84,000 btu Trane compressor & evaporator/condenser) The large heater core under floor is operational as is the dash heat. Original ducting is maintained with ducts going also into bottom compartments. We have 2000 watt heat coils mounted on the under floor heater core for stationary heat. When where not on shore power or running the genny the 34,000 btu LP furnace forced air is distributed by the original otr heating & ventilation ducting - there's redundancy there & options. The greatest thing about using the original ducting over interior space heaters which we also have as option is the warmth is "deeper" in the vehicle so when the furnace (or other options) are blowing through the original ducting - at the end of a heat cycle - the cabin stays warmer for a longer period of time before another cycle starts. Alaska was always on our minds even back in the 70s -80s when we were converting the ole' girl.
Quote from: Jeremy on September 06, 2018, 04:52:04 PM
I dare say they'd do a decent job of heating the interior of a VW microbus or something, but I think you'd be disappointed using them in anything bigger.
Jeremy
Or a standalone recirc'd windshield defroster.
dtcerrato: can you go intomore detail on that? I'm at a crossroads here and very much like the idea of using the OTR ducting. Any photos of the propane system?
As an engine pre-heat you want the engine heated in minutes.
This is Sure Marine's statement
The TSL-17-24 is the smallest water heater offered by Webasto and will heat up to a 38 foot sailboat or a 34 foot powerboat.
Quote from: Lee Bradley on September 06, 2018, 11:51:13 PM
As an engine pre-heat you want the engine heated in minutes.
This is Sure Marine's statement
The TSL-17-24 is the smallest water heater offered by Webasto and will heat up to a 38 foot sailboat or a 34 foot powerboat.
"The TSL 17 is not designed for a live aboard application. If you wish to heat your boat for this purpose, please contact Great Lakes Marine Specialties (NavStore) for advice."
In as much as this isn't a boating board, probably I wasn't suggesting that it be used in a boat. Only pointing out that it has the btu output to heat that size boat and would probably be enough heat for a bus in a mild climate.
But, back to the OP...
He's in Minnesota - not a mild climate by any means. Heating a bus in a mild climate is easy. Drop the temps to sub-zero for a few days and try to heat with one of those and you'll find that 17K btu don't go very far anymore.
Quote from: richard5933 on September 07, 2018, 12:58:33 PM
But, back to the OP...
and you'll find that 17K btu don't go very far anymore.
Likewise, if 17K btu won't heat, it won't cool either :)
Quote from: eagle19952 on September 07, 2018, 03:57:59 PM
Likewise, if 17K btu won't heat, it won't cool either :)
Except that in the summer we're talking about maybe 30-40 degrees that we're trying to cool the bus. If it's 110F outside and we want to drop the temp to 70F it's only a 40-degree shift.
If it's -10F outside and we want the bus to be 70F inside we're now trying to shift the temperature 80 degrees.
Quote from: eagle19952 on September 07, 2018, 03:57:59 PM
Likewise, if 17K btu won't heat, it won't cool either :)
Humm? Did I miss something here? Could be. I thought that Webasto Air Tops were forced air heating, not coolant heaters. Certainly not air conditioners.
neoneddy we run an LP Attwood Excalibur 23-34. It can be used as a 23,000 or 34,000 btu furnace or auto mode set by thermostat. If the thermo reads greater than 2 degree drop while running it steps up the btu & fan speed. We ducted two 4" rnd ducts into each main original heating & ventilation duct - driver side/pass side. In the photo the two 4" rnd ducts on the left are going into the bottom compartment transfer duct to get it to the pass side. the two 4 " rnd on the right (elbowed) penetrate the large original alum duct in the background for driver side. There is a transfer duct that brings heat to the other side of the bus. These two original ducts run the entire length and dump heat everywhere including radiant heat from the alum ducts under the cabinetry. There is another 11,000 btu radiant heater in the hallway leading into the master BR that can flow 1/2 of it's heat into the insulated holding tank compartment below. We carry six 30 LB cylinders all portable with four manifolded into two pairs each side the auto changeover regulator. The other two cylinders can be used for propane injection on the main engine or transported for filling to replace a depleted pair on the house LP regulator. If we sit for a spell we rent a huge tank that gets service by truck. We rely heavy on LP. Easy to boon dock. Besides the 6 gal LP water heater we have a 19 gal electric (110vac). In 38 years in the same bus with 1/2 that time full timing we have it pretty much down pat. Small bus, it's a turtle but we don't hurry - that's when we leave the rat race - when we get in the bus & go far north.
For bus heat going down the road, I used the heater element from the over the road A/C system I removed. I remounted the element going for and aft at floor level in the hallway under my hanging closet. I have 2-14" 12v radiator fans to push the hot air out. Also have a ball valve to cut off the coolant to the element in summer. Works very well to heat the bus. Good Luck, TomC
Quote from: TomC on September 07, 2018, 10:23:54 PMFor bus heat going down the road, I used the heater element from the over the road A/C system I removed. I remounted the element going for and aft at floor level in the hallway under my hanging closet. I have 2-14" 12v radiator fans to push the hot air out. Also have a ball valve to cut off the coolant to the element in summer. Works very well to heat the bus. Good Luck, TomC
Simple, compact, efficient, effective. I like it.
I used school bus heater boxes that came with varible speed fans. They are built in and work great. I then used the OEM heater core as a second radiator for the engine with 3ea 12" automotive electric fans.
On my Fishbowl with the 6V92 I have the DBW 2010 Webasto plumped into the engine cooling system. the water leaves the engine and goes to the Webasto, then goes thru a heat exchanger on the side of my 110 electric water heater. From there the water goes to a manifold, if I wanted to heat engine only I would open one valve on the side of the manifold. The water leaves the manifold and heads to the Onan 7.5 diesel then returns back to the engine. The manifold also has a loop to a heater in the bathroom that utilizes a old rad core from the front heater with a pancake fan to power the air flow. The original front defroster and heater and the under the floor heater are still in the place and used as intended.
The interesting result is when i am running the generator ( summer or Winter ) the generator will heat the 6V92 to approx 140 degrees when camped.
I have turned on the under floor heater fans with the diversion vents to expell the hot air to under the bus to add extra cooling of the 6V92 in he summer heat. The diversion vents are closed in the winter.
I leave all valves open most of the time so all loops are hot and ready helps with cooling in the summer with the bigger cooling capacity.
Going down the road with everything flowing the water in the electric water heater is almost too hot and i have a tempering valve to install to prevent scalding water from the potable water side.
That's similar to how Custom Coach set up the 4106 we used to own. The generator used the bus's radiator for cooling along with a supplemental electric fan. Running either the generator or the main engine caused the other to be brought up to temp once the thermostat opened. The Webasto was plumbed into the system through a side loop - turn on the secondary electric pump and the Webasto heat was circulated to both the generator and main engine. Turn off the secondary pump and the Webasto heated only the loop that heated the interior. Worked like a champ. The great thing was that running any one of the three helped to warm the others. Wake up in the morning after a cold night, flip a switch to turn on the pump, and 30 minutes later the engine was warm.
There were lots of extra plumbing parts brazed into place to make that system work, and I'm told that it was tricky to work it out so that things would function properly. I'm not sure I could ever duplicate it, but I might try one day if I ever upgrade our 4108 to a Webasto.
Quote from: Geoff on September 08, 2018, 08:00:00 AM
I used school bus heater boxes that came with varible speed fans. They are built in and work great. I then used the OEM heater core as a second radiator for the engine with 3ea 12" automotive electric fans.
A few of my heaters.....
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FySrqN2Ih.jpg&hash=ef2373c376db29b1b983ab58c4a02cbef13a583d) (https://imgur.com/ySrqN2I)
Paul I've seen your fishbowl, you have enough redundancy built into it to heat several buses! Then of coarse you are 1/2 way to AK from us. So I guess its all relative. :-)
How does the solar work for heating you see a lot of it now on Rv's and boats both for water heating and cabin heat
Thanks Dan I believe when you drive in the cold or live in the cold you better be prepared.
Things freeze up fast when something quits.
As long as one of the diesels start I got it all covered. :D
Quote from: luvrbus on September 08, 2018, 04:46:56 PM
How does the solar work for heating you see a lot of it now on Rv's and boats both for water heating and cabin heat
Now you've got me pondering...
I just found a system like you're talking about. https://www.solartechdirect.com/collections/water-heating-kits/products/heliatos-solar-rv-or-boat-freeze-protected-solar-water-heating-kit
Quite interesting, especially since our water heater has an unused heat exchanger built into it that could be used with this system. Might be the answer to our question of how to heat water when we're not plugged in. If we decide to take the plunge on this next spring I'll report back.
I have 3 x water panels like this ( but are pressurized ) for domestic hot water at my house and it is installed pre the regular water heater and with full sun the regular water heater never turns on
and 4x of the same panels that heat my bus barn when the sun shines
https://shop.latitude51solar.ca/evacuated-tube-solar-collectors-p/tz-58-1800-20r.htm
only problem with this on a coach is it takes up a lot of space
dave
That's the thing-- some people don't want ANYTHING on their roofs because it detracts from the original bus look, while others go for roof air, vents, satellite dish, and solar panels.
Paso One
I have been thinking about using the OTR Heat core to cool the engine as well. If you don't mind can you tell me how you diverted the heat in the summer to the outside? I have been trying to figure out how to do that. What kind of diversion vent did you use? Do you have any pics?
Quote from: Paso One on September 08, 2018, 08:56:12 AM
On my Fishbowl with the 6V92 I have the DBW 2010 Webasto plumped into the engine cooling system. the water leaves the engine and goes to the Webasto, then goes thru a heat exchanger on the side of my 110 electric water heater. From there the water goes to a manifold, if I wanted to heat engine only I would open one valve on the side of the manifold. The water leaves the manifold and heads to the Onan 7.5 diesel then returns back to the engine. The manifold also has a loop to a heater in the bathroom that utilizes a old rad core from the front heater with a pancake fan to power the air flow. The original front defroster and heater and the under the floor heater are still in the place and used as intended.
The interesting result is when i am running the generator ( summer or Winter ) the generator will heat the 6V92 to approx 140 degrees when camped.
I have turned on the under floor heater fans with the diversion vents to expell the hot air to under the bus to add extra cooling of the 6V92 in he summer heat. The diversion vents are closed in the winter.
I leave all valves open most of the time so all loops are hot and ready helps with cooling in the summer with the bigger cooling capacity.
Going down the road with everything flowing the water in the electric water heater is almost too hot and i have a tempering valve to install to prevent scalding water from the potable water side.
lost two long winded posts tonight I'll post pictures first then try repost the words.
Maybe too large together
Sorry i missed your original post DT rattled my cage and i responded but lost it.
When the air goes thru the OTR heater it goes towards the back and branches off to each side, then turns up towards the inside of the bus.
I cut a door and put two hinges and a slide lock when i don't want heat going into the coach i open the door and it blasts out to the ground.
The passenger side i just installed a vent that blows onto the top of the tank. (cheap tank heater)
It works good with the door open and the coach heat fans on high. I can see the temp gauge moving downward. Lots of extra radiator to dissipate heat.
I'm having a hard time figuring out what I am looking at in this pic. I see the door but I can't figure out where it is in the bus. Could you help me out? THanks
Quote from: Paso One on September 22, 2018, 06:30:34 PM
lost two long winded posts tonight I'll post pictures first then try repost the words.
Maybe too large together
Follow the heat ducts at some point they will turn upward to enter the coach.
The picture is on my transit fishbowl so i'm looking from the ground up.
If you have bays the duct work is likely in one of the bays.
All i did was allow an exit for the hot air prior to going into the coach.
Hope that is clearer than mud. :)
In my MCI it's reverse, 2 ducts coming up and the rest are all returns via the center tunnel.