Hot Air Heater Ducting

T

TonyS

Well-Known Member
Joined
23 Feb 2003
Messages
616
Location
Southampton, UK
Visit site
Has anyone seen the letter in the Feb edition of YM headed "Cut-Price Heat" on page 21 where a Les Green suggests using a 1 metre length of flexible stainless steel pipe from a caravan shop followed by 70 mm plastic rain water pipe. I need some ducting for my heater and this sounds a good solution but will the plastic pipe withstand the temperature?

<hr width=100% size=1>Tony
 
I wouldn't do it that way, but it has obviously been working for him. What sort of length are you looking at?

I spent an age trying to source flexi pipe of any kind in the eber size before giving up and going to a truck depot for some eberspacher pipe. It was not cheep, but now I am not worried about it failing through heat etc.

But as said, it worked for someone so go for it, if it does not work then what have you lost a few quid?

<hr width=100% size=1>Julian

<A target="_blank" HREF=http://www.topcatsail.co.uk>Top Cat Homepage</A>
 
Thanks, I am looking for about 7 metres. Do you know what the softening point of PVC is? In the earlier post it was stated that the output temperature is less than 116°C.

<hr width=100% size=1>Tony
 
That output temp was for the exhaust, so much lower for ducting, try the tech manuals on <A target="_blank" HREF=http://www.espar.com>http://www.espar.com</A> they might shed some light.

I read an article in PBO last year about molding your own perspex fittings, where you put them in the over at something like 120°C for a couple of minutes. This might be a mile off, but it also may give some small indication of plastic melting.

<hr width=100% size=1>Julian

<A target="_blank" HREF=http://www.topcatsail.co.uk>Top Cat Homepage</A>
 
Not sure that the air temp will be as high as 116 C.....certainly not at any distance from the heater. Ordinary pvc starts to get really soft at 70C, There's several sorts of plastic for waste pipes anyway,abs, upvc etc.

Imagine the stainless is for the hot part nearest the heater, then plastic OK. Think I've seen 70mm ducting for extractors in electrical merchants(but can't be sure).....if same as the 100mm/125mm is aluminium foil with wire reinforcement, think this wd be ok too.

<hr width=100% size=1>
 
i remember bodging a rad pipe on my scimitar car years ago with a bit of water plastic pipe, it lasted 10 mins before it deformed with the heat, i suspect the same will happen with the rain water pipe, my eberspacher ducting is that hot even 2 metres away from the machine that i reckon you can burn yourself!!
stu

<hr width=100% size=1>http://www.beneteau-owners-association.org.uk
 
Do a google search for air conditioning suppliers and duct /flexible suppliers uk.
Regards
Rob

<hr width=100% size=1><A target="_blank" HREF=http://www.rejuvanu.com>RejuVanu</A>
 
Yes, the plastic does stand the heat, just....
When I fitted my heater I ran it with rainwater pipe right from the heater mouth on the basis of that will get it working and I can get the proper stuff later. Nearly two years on and its still there and working fine. It does get a little soft but only to a point, it wont collapse in on itself. I am thinking of changing it but I certainly don't have to.


Mike....

<hr width=100% size=1>
 
Re: Heater Ducting - really cheap!

Why buy plastic rainwater pipe I ask? Collect the large size dishwashing liquid containers (the ones that PBO urge us to use) lop off the tops and bottoms and glue them together. Bingo.

Do you love your boat? Of course you do -so do it right and buy the right gear!
Plastic drainpipes, I ask you....that'll look good at survey, I bet!

PWG

<hr width=100% size=1>
 
Re: Heater Ducting - really cheap!

That had me laughing....a "blue peter" boat ?- don't forget some sticky back plastic.

Seriously though....just how expensive is the proper hose? there must be loads of sources for duecting capable of the temperatures involved, so just wondered how much the stuff sold by heater companies is.

<hr width=100% size=1>
 
Re: Heater Ducting - really cheap!

Should we be worried about the surrounding area in the vicinity of the stainless ducting? I guess it will conduct heat much better than the proper Eberspacher tube so it might get the surroundings too hot - in particular, I'd be worried if it passed through a bulkhead while still close to the heater outlet but I don't know if this is a justified concern...

<hr width=100% size=1>
 
You must log in or register to reply here.

Share this page

Top