Hot air ducting

[pcatterall]

I need to replace the old 60mm ducting for my'new' gas blower. The old stuff is just disintigrating (after a mere 30years!!)
I wondered if one could use something in common use like plastic drain pipe rather than expensive flexi stuff (except where you needed to wriggle it through sections. This is partly cost but wouldnt straight tube have less drag and may be more robust in lockers. I would of course be insulating the tube whichever I used. Can ordinary pvc take the heat?
Regards.

 

[cliff]

NO. Under no circumstances use plastic drain pipe.

From bitter experience drain pipe will collapse with the heat.

I used "emission control" ducting from a motor factors. Flexible aluminium ducting which comes in various sizes (50mm, 55mm, 60mm, 65mm, 70mm, 75mm)

IIRC 5M of 60mm cost me ~£20 and it is "telescopic" so any excess can be concertina'd and excess length "lost".

Only down side was it had to be insulated to maintain the heat and prevent burns. - oh and it did pong a wee bit when new but a few hours running the eber on full heat soon got rid of the smell.
--------------------

"Artificial intelligence is no match for natural stupidity"

 

[andyball]

i've seen eber & truma parts lists that show lengths of rigid ducting & fitting guides that recommend it where possible.

yr average cheapy drain pipe won't take the heat, stuff that will prob costs more than heater ducting, the cheap ducting that concertinas up will add even more resistance to air flow.

Worth checking trumas lists ( & eber, but more expensive, I think) - they both do remote shut-off & changeover valves which are a much better solution than a long run with a closeable vent at the end imo, esp if trying to get maximum heat in one place when it's really cold.


Re yr post a while back about truma - many many german & dutch boats are fitted with these as std. also loads of caravan/motorhomes here & abroad.

 

[linsayh]

Need to replace ours also.

Spoke to Eber' at LIBS who advised that whatever I chose to use (I've been looking for thermoplastic) must be rated to at least 140DegC.

I see that Mikuni comes with plastic(?) hose.

 

[pcatterall]

Thanks for the advice to date. My caravan shop is going to supply semi rigid ducting for £5.8 per m. Better than £12 for the flexible stuff.
I tested 'drain pipe' at 120 degrees in the pressure cooker (Hope SWIMBO doesn't read this) it did'nt melt but became slightly oval where it was suspended so no go there.
Interesting to read that Ebber recommend 140 degrees capability, a PBO article recommended use of insulation (Armaflex) which was rated only up to 120 degrees.
Thanks again.