Propex heater install sanity check

MagicalArmchair

MagicalArmchair

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Has anyone got any decent photos of their install? I'm looking to do the below:

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The Y bend will be immediately after the Propex unit and the run to the 'non' opening vent will be very short, will that be a problem?

As for afixing the Propex unit down, as I look to be someway aft of the bulkhead, I will either fiberglass some bearers onto the hull, or I could mount it on the bottom of the deck?

As for the gas fitting, I'm going to use soft copper and run it as below:

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Shopping list includes:

With a t piece to go to the cooker and hose connectors in the Gas locker to go to the regulator and for the final run to the cooker.

Any suggestions? Does the above look sound?
 
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Not sure the scale of your diagrams but be very careful and follow the Propex guidelines re the maximum length of exhaust and hot air ducting hose. Try and avoid bends, but if not possible make them as "sweeping" as possible.You might find having a short run after the Y piece could rob the the other outlet further down the line. You could fit another closable outlet in the first position to balance the system up if you found it a problem. The only problem I have had with Propex installations is the length of the ducting/exhaust, if slightly over length the low air flow sensor will close the system down - the dreaded 5 flash fault code ! Earlier Propex heaters with the mechanical Hall effect sensor were the devil for this ! I retrofitted the newer non moving air flow sensor - a great improvement. If however yours is a new unit this will be the standard fit anyway. Regarding the gas supply, probably fine, others with more knowledge could advise, sometimes if feeding over a longer line putting a T in can starve either of the appliances, but suspect yours is fine. I have a separate bottle for mine. Easier to plumb at the time and it gives e a "spare" for cooking if needed. Regarding installation, protect from water, obvious I know, but it is only a mild steel casing. Mine is very hidden away under the cockpit floor, mounted on a ply sub panel which is slid into place and then remotely bolted to the cockpit sides. Once in, a mirror on a stick job to see it. Bit like sliding a ship into a bottle! You sound as if you have more room. Good luck !
 
I think the gas supply will be perfectly adequate. My stove is supplied by 1/4" copper and used to have a catalytic heater supplied from the same tube via a Tee. We could run both burners, oven and heater at the same time.

I agree with DickieT, having such a short ducting run to the open end may starve the long ducting into the saloon. I think I would reverse your arrangement with the open vent in the saloon. Closing the outlet in the quarter berth would then heat the saloon, whereas the back pressure in the long run would probably drive enough flow through the opened outlet when required.
 
MagicalArmchair said:
Shopping list includes:

With a t piece to go to the cooker and hose connectors in the Gas locker to go to the regulator and for the final run to the cooker.

Any suggestions? Does the above look sound?
Click to expand...

I'd be inclined to add an isolating valve on both legs of the 'T'. Useful if either item of equipment springs a leak or needs to be removed for repair.
 
I looked into fitting a propex but the limits on exhaust and duct length didn't make it viable. It is quite limited.
 
I have a y immediately after the heater and a run of about a foot to the always open vent. The other tube does almost a 360 deg turn and runs about 10 ft to an open/close vent. When both vents are open there is no difference in the amount of hot air coming out. I really like these modern Propex heaters, Like for like they seem so much hotter than an Eberspacher and the fans are powerful. I don't think I would ever go back to a diesel heater.
 
Thanks all. The ducting and exhaust lengths do make life tricky, the 'rules' are as follows:

  • The first 'always open' vent must be within 1.5m of the unit (vyv_cox, hence the way around I have it with the opener in the middle of the saloon), preferably with no sharp bends.
  • The exhaust and combustion hoses (the metal ones that run to the skin fitting) must be no longer than 2m and have a swan neck to the skin fitting to stop water entering the unit.

One thing that does worry me is that that first 'always open' vent is right above where I am going to put the fridge (C is the compressor)...

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...my reasoning is that heat will rise and cool air will fall, so it should be okay? Unless I swap the Propex to the other cockpit locker and have the vent over the chart table instead?
 
On reflection, I might be braver and go for a longer gas run to get the heater away from the fridge and get the outputs closer to the centre of the space to be warmed...

sp7iARB.png


Now to try and route that copper under the cockpit out of the way, ho hum. And good point 42alahol2 adding isolating valves to each run after the T piece, I'll add those to my shopping list.
 
the problem with siting the unit closer to the first outlet means it might be too far from the exhaust skin fitting.
 
Thanks Spyro (cracking name by the way) - Indeed, I have been told by Propex (who have been very helpful despite my barrage of questions to them) that the run to the skin fitting must be a maximum of 2 meters. If my plan above is right, in a straight line it should be 1.5m, giving half a meter of swan neck / rise and fall / general error... I hope...
 
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