Heating system

rusty · Post by **rusty** » Wed Jun 08, 2016 7:27 am

I am starting to do the bay work on my 15. I am going to use a hydronic heat system on the bus. I have been looking at the pro heat system. Has an of you used that system and how do you like it ? I have heard they are a little less expensive to maintain.Also I have been thinking about adding a second electric water heater with a Hydronic coil in it to heat the water for the heat in the coach when on the pole. Do you think that is possible? Also I would like to run the exhaust thru the roof. I know that they say only about 5 feet of exhaust pipe but can I use a larger pipe to over come the back pressure? I am going to get a hold of John Carrillo and get his advice. I know he works on all systems not just the Aqua hot. I am hoping you all have had some advice on the subject.

Wayne

davida · Post by **davida** » Wed Jun 08, 2016 6:41 pm

rusty wrote:I am starting to do the bay work on my 15. I am going to use a hydronic heat system on the bus. I have been looking at the pro heat system. Has an of you used that system and how do you like it ? I have heard they are a little less expensive to maintain.Also I have been thinking about adding a second electric water heater with a Hydronic coil in it to heat the water for the heat in the coach when on the pole. Do you think that is possible? Also I would like to run the exhaust thru the roof. I know that they say only about 5 feet of exhaust pipe but can I use a larger pipe to over come the back pressure? I am going to get a hold of John Carrillo and get his advice. I know he works on all systems not just the Aqua hot. I am hoping you all have had some advice on the subject.

Wayne

I can't comment about a Proheat since I have a Webasto DB2010. I do like it but it does require regular maintenance. I have the 40k heat exchanger to scavenge engine heat on the road to use the system to heat the coach which works very well. I had a long horizontal exhaust pipe which gave me problems of sooting up the chamber. I shortened it to about 4.5' and I slip a 1.5" EMT elbow and 10' up pipe (EMT) attached to my drip rail to exhaust above the roof. I haven't had any problems with that. I stow the pipe in a rack under the bus while traveling.

One issue I have is that when the unit runs I get a slight smell of spent fuel in the coach. This is really annoying to me. The unit is fan forced in the burner chamber, so it is pressurized and some smell leaks out between the head and chamber into the bay and percolates into the coach. To remedy this I turn on my bathroom exhaust forcing air in to "pressurize" the coach. It only takes just a tiny amount of air to do the job.

I originally installed four 7k btu fan heaters in the coach and one in the water tank bay for 35k btu of heat. It wasn't enough for the lounge. I later added one 4' fin strip under the sofa and 2 Heatrim radiant strips on the opposite side which gave about 7k more btu's in the lounge. The fin strip under the couch is really nice because the heat radiates up behind the sofa, up the cold window glass. Very nice. So, I'm running 42k btu's heat exchange from a 40k btu furnace. It also runs through a Seaward 11 gal water heater. When in the mid 20's the coach is toasty warm and the furnace still reaches its cutout limit before the wall t-stats reach desired room temps.

On your plumbing you need to have a summer and winter loop if you plan on heating water without heating the coach. I did this with a T handle 3 way valve in the bay. The common is heated water in. One direction out goes to the heaters and water heater. The other direction out goes to the water heater only bypassing everything above the floor line. Since I heat my domestic water from engine heat while rolling this is important to have in the summer. I don't want any lines, radiators, or fan heaters above the floor line in the coach to be heated in the summer.

My expansion tank it high up in the engine bay. It must be the highest fixture in the loop. You probably know that already. Even though it is high in the engine room it is still only about 6" higher than the floor, so when using the system I make sure the coach is level or front end low to avoid any airlocks. You can locate them in a closet in the coach, but that could be messy when adding coolant.

My unit is 15 years old now in my Eagle.

David

rusty · Post by **rusty** » Thu Jun 09, 2016 7:00 am

David a couple of ? about your exhaust. If memory serves me the exhaust on an webasto is 1 1/4 inches. your first try with the long horizontal exhaust was it 1 1/4 the whole way ? Then with your second exhaust when you put the 1 1/2 EMT on is it a tight fit or is there space in the joint? I am thinking of running the exhaust up through the coach. May be it can be done with a larger pipe ( maybe 2 inch ) . The connection can be outside under the bus with a lose connection from the 1 1/4 to the 2 inch to let in draw some cooler air through the lose connection.

Thank You Wayne

blue_goose · Post by **blue_goose** » Fri Jun 10, 2016 7:35 am

If you put the exhaust out the roof you may get soot every time the unit starts up.
Jack

rusty · Post by **rusty** » Fri Jun 10, 2016 9:39 am

Jack is that because things need to heat up before the exhaust starts to move up on it's own.

I have had the aqua hot system for 13 years and like it very well. This spring we were visiting some friend in Tennessee and was boondocking at their property on the duck river. It was warm enough that we slept with the windows open. A couple of nights I left the heater on as I needed it to heat the domestic hot water. One night the heater went off and it woke me up ( not because it was too loud but because a mouse walking across the carpet will wake me up) and a while later the fumes came thru the window. That is the first time that ever happen. I ques most of the time the windows are closed. It was that point that I started thinking about getting the fumes up high for me and the ones around me.

Wayne

davida · Post by **davida** » Fri Jun 10, 2016 3:02 pm

rusty wrote:David a couple of ? about your exhaust. If memory serves me the exhaust on an webasto is 1 1/4 inches. your first try with the long horizontal exhaust was it 1 1/4 the whole way ? Then with your second exhaust when you put the 1 1/2 EMT on is it a tight fit or is there space in the joint? I am thinking of running the exhaust up through the coach. May be it can be done with a larger pipe ( maybe 2 inch ) . The connection can be outside under the bus with a lose connection from the 1 1/4 to the 2 inch to let in draw some cooler air through the lose connection.

Thank You Wayne

Yes, the exhaust is 1.25" and the 1.5"emt elbow slips over it, and it is not sealed there, but with the venturri effect it shouldn't leak at all. It is located at the edge of the bus under the bay. When I slip the ell on it, it swings up and I slip the 10' pipe on the ell with an EMT connector. I have a stand off mast that clamps the pipe to the drip rail.

You could attempt to bury this in your wall. I'm not an engineer, but logic tells me a 2" pipe would be better for back pressure than 1.5". Think this through, though. You will have a roof penetration (leak point). You will have to insulate for fire protection (pipe gets about 400-500 degrees). Rain water can get in the pipe and settle at the bottom (rust out in 4-5 years) I don't see much advantage. I use my heater so little that the up pipe is really no problem for me. It is no different than putting out or rolling up the awning when arriving or leaving. Since I don't use the furnace when under way because of the engine heat exchanger, exhaust while rolling is not an issue. I have used it while rolling and the exhaust just blows out the side.

One other thing I forgot. These furnaces do produce some soot over time, so before I put the up pipe on I fire it up and let any accumulation blow out the side. It does throw out a puff of soot. I wouldn't want that blown on my roof. It seems to stick to anything in its path. It's like carbon black.

I forgot to tell you that I also use the furnace to preheat the engine through the heat exchanger.

David

blue_goose · Post by **blue_goose** » Sat Jun 11, 2016 6:13 am

If you look when the generator starts up you will see a puff of black, because it starts rich. The furnace also runs rich until it is up to temp. Hang a white cloth at the end of your exhaust pipe and start the unit. I don't have a hot water unit, but mine is hot air and every time it starts there is blue smoke and some soot that comes out.
Jack

davida · Post by **davida** » Sat Jun 11, 2016 6:40 pm

rusty wrote:Jack is that because things need to heat up before the exhaust starts to move up on it's own.

I have had the aqua hot system for 13 years and like it very well. This spring we were visiting some friend in Tennessee and was boondocking at their property on the duck river. It was warm enough that we slept with the windows open. A couple of nights I left the heater on as I needed it to heat the domestic hot water. One night the heater went off and it woke me up ( not because it was too loud but because a mouse walking across the carpet will wake me up) and a while later the fumes came thru the window. That is the first time that ever happen. I ques most of the time the windows are closed. It was that point that I started thinking about getting the fumes up high for me and the ones around me.

Wayne

I reread your post about the pipe fit. Yes, my original horizontal installation was 1.25" full length. The 1.5" EMT 90 degree bend slides snugly over the 1.25" pipe, no fittings required. It fits over my genny pipe, too if needed. As a courtesy to my neighbors, I always use an up pipe for webasto or genny if I'm around other campers. You're on the right thought pattern about getting fumes up high and away. For me it was just too easy to make it cheap and portable without lots of engineering.

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