Propex Heater install questions

[SameGuy]

My Propex HS2211 just arrived today. I'm working on the install in my Little Guy Sport 6 Wide. (pictures to come as the project progresses) This model can mount vertically and my plan is to attach it to the back wall of the galley and duct it into the camper. Ducting the actual heat seems pretty straight forward but ducting the exhaust and air intake has me asking a few questions. Manual says the combustion air inlet flue must be at least 500 mm (19.5 inches) from the open end of the exhaust flue. Is this so the combustion air intake isn't sucking in exhaust, and in turn, lower than ambient oxygen %? I guess I get that but 20 inches seems a bit excessive. The next items I really don't get. IT says the Minimum length of the exhaust flue has to be .75m (30 inches) and max 2m (6.5ft) and the lengths of the intake must be between 1 and 2 meters. Why would the length of the intake flue make any difference and why does there have to be a specific length for the exhaust? With these constraints I an going to be running exhaust out one side and intake from the other, quite a bit more plumbing than seems necessary.

 

[Martyn]

To mount this unit safely stick with the minimum distance for locating the exhaust and air intakes.

The length of the air intake is critical as full combustion of the propane relies on a turbulent air flow. The turbulence is provided by the ribs on the inside of the air tube.

If you deviate from the lengths the unit will shut down and flash a series of error codes.

Having worked with this brand for years I strongly recommend you don't second guess their instructions.

 

[SameGuy]

Martyn,
Thank you very much for the reply. I have no intention on doing anything not clearly outlined in the instructions. There are times to break the rules but this isn't going to be one of them. I had some down time so I did some more layout on my little camper with the heater and accompanying plumbing. This thing is going to be really slick once I get it all installed, not to mention all the new hole saws I am going to need to finish things off. Will put up pictured next time and ask some silly questions then too.

 

[Martyn]

Martyn,
Thank you very much for the reply. I have no intention on doing anything not clearly outlined in the instructions. There are times to break the rules but this isn't going to be one of them. I had some down time so I did some more layout on my little camper with the heater and accompanying plumbing. This thing is going to be really slick once I get it all installed, not to mention all the new hole saws I am going to need to finish things off. Will put up pictured next time and ask some silly questions then too.

I totally understand. There are times you can bend the rules to fit your needs, but in this case it won't work. I know I tried it with this design and it didn't work. For something the size of a shoe box it's quite sophisticated.

 

[TenaciousTJ]

Any updates or photos?

 

[VDBAZFJ]

Reviving this in hopes someone can answer another question regarding the intake flue.
Is it acceptable to coil the intake flue so that I can get it to fit within my parameters? This isn’t technically shortening the length. Basically creating a 1 foot diameter coil.
Real estate is a premium as well as aesthetics. But function is just as important. Any thoughts?

 

[Martyn]

Coiling it should be fine, creating sharp bends or kinks is a no no.

 

[VDBAZFJ]

Thank you Martyn!

 

[dhally]

We've had a Propex for 10 years in our van. It stopped working due to an accumulation of dust finally plugging the air flow sensor. The point being...make sure you can UNINSTALL the heater some day, and tge tubing!! I had to rework some cabinetry and tubing supports. Not fun.

The intake and exhaust also should be sloped so water doesn't run into the heater.