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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: neoneddy on October 09, 2018, 10:00:40 PM

Title: Propane furnace install options round up, lay it on me.
Post by: neoneddy on October 09, 2018, 10:00:40 PM
I've got my annual Dukuth Hockey tourney coming up and invented a few folks to bunk at my place.  So that means I'll need heat while parked.

I have a 25k BTU duotherm furnace. It has outlets on the sides and bottom. Looks like I can configure it.

I don't want to put holes in the side, so I'm thinking Bay mounting.  The trick is, the air return on this is made to be inside.

If it ever stops raining I hope to do some test installs. Until then what's everyone been doing ?
Title: Re: Propane furnace install options round up, lay it on me.
Post by: chessie4905 on October 10, 2018, 02:41:28 AM
In the shop installing the pulse air wiper kit, King cruise control, and electric sun visors. Almost done. Next up is manual leveling system for campsites.
Title: Re: Propane furnace install options round up, lay it on me.
Post by: TomC on October 11, 2018, 08:20:26 AM
You MUST have outside venting for a propane furnace. Suburban has the smallest vent. Good Luck, TomC
Title: Re: Propane furnace install options round up, lay it on me.
Post by: neoneddy on October 11, 2018, 08:42:13 AM
Yeah, that's the plan.  I'd hoping to make a small hole in the floor of the bay, and run the exhaust into a bent pipe out the side.
Title: Re: Propane furnace install options round up, lay it on me.
Post by: Bill Gerrie on October 11, 2018, 09:31:57 AM
neoneddy
You need a vent into the bus to get return air and DO NOT restrict the 3 outlets. The furnace will over heat if not enough air flow. You need fresh air into the burner as well as the exhaust outside.
Title: Re: Propane furnace install options round up, lay it on me.
Post by: Gordie Allen on October 14, 2018, 07:36:04 AM
Most propane heaters have two pipes; one for combustion air (in) and one for exhaust (out). The exhaust side will get HOT.
Title: Re: Propane furnace install options round up, lay it on me.
Post by: Bill Gerrie on October 15, 2018, 11:25:18 AM
Gordie
I mean't the three outlets for heating the coach. Yes there is only two for the intake and exhaust pipes.
Title: Re: Propane furnace install options round up, lay it on me.
Post by: neoneddy on October 15, 2018, 12:44:12 PM
I installed it yesterday.

I cut 2 holes into the main OTR Air ducts with an adjustable elbow angling it up.

Then I positioned the furnace next to the wood access door for the OTR heater core, I marked both the door and the furnace.  I then cut a hole in the door and the side of the furnace for the air return.   As I understand it, I'm pulling air from the stock OTR air returns and pushing hot air out the OTR vents.  So far so good.  I used some spray adhesive and foam to insulate and seal the return connection (just flush / butt mounted).

I then duct taped over the original air return grate and installed the factory cover to seal it up.

First, I plugged in my CO detector, right above the floor vent.

I fired it up and within a few minutes saw the thermostat indicated temp rising, from 44 to 45 ... then eventually 46, but I started to notice it getting a bit hazy inside. I've  read this can be normal for first operation in a long while or new furnace.  I had tipping the furnace every which way getting it in and drilling holes, sounds like it could just be burning off some saw dust from the hole I cut.

My more serious issue is the flame inside the burner is blue all the way around except in one side (of 3 main runners) is yellow.   It initially didn't worry me, but I'm also noticing black soot in the exhaust.    So today I'll be pulling it out and taking a look a the burner.   
Title: Re: Propane furnace install options round up, lay it on me.
Post by: TomC on October 16, 2018, 08:36:13 AM
Yellow flame means not enough combustion air for the burner. Make sure the burner vents are open enough to get blue flame.
Title: Re: Propane furnace install options round up, lay it on me.
Post by: richard5933 on October 16, 2018, 11:24:38 AM
What did you do to provide for combustion air intake and for exhaust output? Could the combustion intake be too long or have too many bends which act as a restriction?
Title: Re: Propane furnace install options round up, lay it on me.
Post by: neoneddy on October 16, 2018, 11:37:32 AM
I did no extra piping for intake combustion intake.  I figured the bay isn't air tight, it will breather fine.  During this test I had both bay doors open, I don't believe intake restriction was an issue from  there, it could be restricted internally however.
Title: Re: Propane furnace install options round up, lay it on me.
Post by: neoneddy on October 17, 2018, 07:02:09 AM
Ok did a tear down and compressed air cleaned out of the burner assembly. It fired up nicely , no soot.

It's not nearly big enough to properly heat the coach but it's fine for our needs.  It was in the 30s and kept it at 63 for a few hours. If I supplement with an electric heater I can keep raising the temp, but I think we'll be fine for late and early season use.