Kelpie
Well-Known Member
I've never had a silencer on either of my boats which had these heaters.
Chinese heater.
- Thread starter iantomlinson
- Start date
Wing Mark
Well-Known Member
The exhaust must be lagged, other wise the water from burning the diesel will condense and fill the exhaust over time.
I'm going for a double layer of 3mm thick glass lagging
Exhaust Lagging 75mm x 3mm x 5m.Narrowboat,cruiser,dutchbarge,fishingboat,engine | eBay
plus whatever I can salvage of the glass braid 'sock'.
I have some stuff like this, ali tape, to keep the lagging in order (I hope).
Heat Shield Wrap Tape Auto Exhaust Pipe Adhesive Reflective Aluminum Foil Gold | eBay
The exhaust tube, I'm using the corrugated section which came with my heater, plus a length of 24mm OD SS tube.
I have formed a slight 'down section' leading to the terminal, which is quite high up the transom
The exhaust terminal was already with the boat, it's supposed to slope down to keep the rain out, but that's negated by the slope of the transom.
I'm going to box off the lagged exhaust to protect it and my rubber dinghy from each other. The dinghy won't like the heat and the exhaust wont like 20 kilos of dinghy leaning on it.
Bearing mind the old exhaust had split due to stress (?), I will add some support half way along, make a bracket to an existing bolt.
If the lagging isn't enough, and I get condensate in the exhaust at low power, I will install a different exhaust with a drain point to a catch bottle.
I was looking at someone else's 'pro' installed webasto today, the exhaust just leaks and dribbles into the locker.
I don't know the best source of ducting, I'm using the existing. Everything is on ebay, but quality varies. In a previous life I bought ducting from Merlin Motorsport at Castle Combe. FWIW.
Hope that help a bit?
I'm learning as I go too!.
fredrussell
Well-Known Member
I get the physics of this, but surely any water that collects in there would be vaporised fairly instantly by the extreme hotness of the exhaust gases?
Kelpie
Well-Known Member
The problem comes when it shuts down and isn't run for a long time.
Wing Mark
Well-Known Member
If the exhaust tube is losing heat through the sides, then the gases might be a fair bit cooler than 100degC, by the time they've gone through a metre or so of pipe.
So the water will start to condense and run downhill back toward the heater.
When the heater shuts down there could be enough in there to reach the heater.
The water won't exactly be pure, I'd guess it will corrode the ali of the heater given half a chance!
I'm told that burning a litre of diesel create two litres of water?
I have thermocouples and kit to check the gas temp as it leaves the transom.
But you should be able to see whether it's steaming like a condensing boiler.
oldmanofthehills
Well-Known Member
Though I probably will buy 2nd hand eberspacher not chinese I am intrigued by the thread. Small boats are far from ideal. The exhaust must be above waterline when heeled and outside the confines of the cockpit. Even the transom can be problematic if cockpit canopy up as fumes can be blown in.
However the transom remains best choice unless the boat has high gunwales. And thats were the old D2(2kW) unit is on mine, half a boat length away from where heat is needed and only readily accessible to a trained monkey. So my boot and hose pipe locker is heated, the inflatable dingy sits on cosy floor, but the heat barely gets as far as the pilot house and fails to get to the saloon.
Sadly the only answer seems to be to get a D4 (4kW) unit and put up with the extra current draw. I run it from 3rd battery so I dont lose nav or lights if I run it too long. Fortunately or not my voyage out to sea normal involve running the engine for an hour to get clear of Plymouth sound, but the eberspacher would not suit extended winter pure sailing trips or live aboard
However the transom remains best choice unless the boat has high gunwales. And thats were the old D2(2kW) unit is on mine, half a boat length away from where heat is needed and only readily accessible to a trained monkey. So my boot and hose pipe locker is heated, the inflatable dingy sits on cosy floor, but the heat barely gets as far as the pilot house and fails to get to the saloon.
Sadly the only answer seems to be to get a D4 (4kW) unit and put up with the extra current draw. I run it from 3rd battery so I dont lose nav or lights if I run it too long. Fortunately or not my voyage out to sea normal involve running the engine for an hour to get clear of Plymouth sound, but the eberspacher would not suit extended winter pure sailing trips or live aboard
Wing Mark
Well-Known Member
On my boat, the ducting from heater to saloon is inside another tube, so insulated a bit.
One branch of the ducting runs under the aft bunk.
It's not rocket science to insulate the ducting.
Or to make some use of the stray heat.
Ideally all this malarkey would have been designed in. Alas that does not look to be the case with fairly new boats, let alone 'last century' vessels like ours.
Given a 'clean sheet' to design a boat, and a blank cheque, I might come up with a different answer.
peteK
Well-Known Member
if your heater is old it may only need clea ning the soot out and ducting insulated .
LoneHort
Well-Known Member
I bought one off Amazon for the shed. Great bit of kit think it cost me €120 incl a 24v mean we’ll power supply. Burns a lot better with kerosene though instead of diesel.
Spirit (of Glenans)
Well-Known Member
I have read on another thread that a drain point is only applicable to installations in motor vehicles, where the exhaust is outside the cabin, and would potentially introduce CO into a closed environment such as a boat.
If the acidic condensate would corrode the aluminium internals of a heater, isn't there always the danger that it would corrode an exhaust pipe made of similar metal, also posing the possibility of CO poisoning?
If the acidic condensate would corrode the aluminium internals of a heater, isn't there always the danger that it would corrode an exhaust pipe made of similar metal, also posing the possibility of CO poisoning?
oldmanofthehills
Well-Known Member
The problem is that insulation was £16 a metre last I looked, so thats another £50 and of course the overall diameter increases. As the duct space is behind the diesel tank its rather tight thats an issue- however I dont much like the idea of heating my diesel tank by mischance either. My propex heater in van is a lot less bother and quieter but installing one of them would mean carrying more gas and my wretched gas locker only takes two camping gaz 907s. Small boats!
jmnapier
Well-Known Member
Just being controversial for a moment…. I have modified all my buying to avoid anything identifiably direct from China. I’m not trying to stir up a hot political debate but I do see a real threat from the east over the next few decades and we have handed them our economies on a plate in the last 30 years. If we all do our bit and slowly revert to buying non-Chinese products as much as it is possible things may even out slightly. My present boat has a secondhand Eberspacher, my last had a new Mikuni.
Genuinely not trying to stir things up but it does worry me…..
Genuinely not trying to stir things up but it does worry me…..
webcraft
Well-Known Member
Yeah, and if I could afford it I would not buy Chinese products. If you can afford it I would say go for it, but I can't.
- W
Wing Mark
Well-Known Member
The exhaust is made o f stainless, not aluminium.
If you need a condensate drain, then you need to engineer that in materials which will survive the chemistry.
But if the liquid drains away, the exhaust parts will not be left immersed in concentrated by-products.
I suspect a lot of marine heater exhausts simply leak. The one I took off had a drain hole !
The previous owner had used that for some years without the CO alarm going off.
With any heater I think a CO alarm is sensible.
But there would have to be a lot of CO in my locker for much to reach the cabin.
Also these are powerful heaters, there is no need to close down the boat to keep warm, you can afford to have a hatch open, just as you might with the stove on for longer than it takes to boil a kettle.
If you want a warm dry boat, you have to let some of the warm damp air out,
As I said on a previous thread, it's more like heating a n old car than heating a bedsit. Turn it up full and open the quarter lights to banish the condensation!
Wing Mark
Well-Known Member
You'll just be buying stuff indirectly from China.
Or having a cold boat.
One could equally make a case for not buying from Germany or any other place that's better at making things than the UK.
jmnapier
Well-Known Member
My whole setup of secondhand Eberspacher cost about £300 with all the little missing bits. Although the Chinese heaters are cheap I thought you had to ‘top up’ with all the plumbing etc?
I agree that everything comes from China ultimately but at least a European will make a cut if we buy locally.
No intention to upset anyone but I reckon we can all work towards rebalancing things even in small ways.
I agree that everything comes from China ultimately but at least a European will make a cut if we buy locally.
No intention to upset anyone but I reckon we can all work towards rebalancing things even in small ways.
Kelpie
Well-Known Member
My Chinaspacher cost about £150 including all the extra bits.
I have no sympathy for Eberspacher and Webasto, charging ten times as much for their product whilst engaging in illegal price fixing.
Rappey
Well-Known Member
Isnt that the truth.. there is a youtube guy who does comparisons/shoot outs with tools.. wire cutters to cordless drills etc.. all the usual well known brands and a few cheapys thrown in for good measure.
The shocking thing is virtually all the brands are "made in china" .
oldmanofthehills
Well-Known Member
There have been quite a few dead recently from CO including one at a local YC. Exhaust fitting desoldering, wind blowing fumes into canopy due to vortices by stern and similar, poor exhaust fitting on trawler etc etc. CO poisoning makes you sleepy not alarmed, so multiple battery CO alarms vital. MAIB and other sites make grim reading
iantomlinson
Well-Known Member
I appreciate the china syndrome. I'm the first in line with 'theyre gona hold us to ransom/theyve killed our manufacturing(or we have sold out) and what about our jobs'. but- i cant afford a grand or two for eber or webby so trying the affordable option. As i said at the start of this post; it was to research to proper 316 skin fitting, exhaust,lagging, anti-syphon loop etc etc. I have the co alarms and auto extinguisher etc. I appreciate also the various opinions and views but Can we not concentrate on the original post for a boat???
