Heating on boats

The thing about hot air is, that it will heat the boat up in no time and supply enough heat no matter how cold it is.

We had water filled radiators on a barge, it took hours to warm up and even then it was not warm enough in winter.

That's because it wasn't correctly designed by whoever fitted it. Heating should be sized for the room/s it isnt a matter of fitting a radiator into a gap, correctly designed a wet heating system will be fine, thats why we have them in homes.

Tom
 
That's because it wasn't correctly designed by whoever fitted it. Heating should be sized for the room/s it isnt a matter of fitting a radiator into a gap, correctly designed a wet heating system will be fine, thats why we have them in homes.

Tom

Unfortunately Tom, on a boat, one can't always find the wall space for rads of the right size. Also, the heat loss in boats varies depending on the craft so is probably not so easy to spec.

I've tried really hard with heating solutions because my wife hates feeling cold. On our boats, we have tried Eber and Webasto, air and hydronic systems, and they have both performed about the same.

The air blower systems seem to me to be more reliable and have less reliability issues. Also, since most of the action takes place only in the boiler, any faults are easier to locate and remedy.

The hydronic systems are much more complex with a boiler often running off an external fuel pump. These boilers seem to be more fragile than the air blowers which have been tested in trucks for many years.

Then there are all the issues of having water filled pipes running round your boat. In a house, one never normally goes anywhere near the pipes and fittings once they have been fitted and work properly. However, in a boat, the pipes run under the floors and on a boat one is often doing work servicing various pieces of kit which are located in the same space. This can cause pipe fittings to become dislodged and leak if careless.

The fan matrices in each cabin are each an extra bit of kit that are supplied with electricity and connected to the water circuit, and so have the potential for their own set of problems. I also think that most people couldn't sleep well with them running in the same cabin.

Another consideration is noise. The hydronic systems are noisy. In the smaller boilers there is the clicking noise from fuel pump, but this can be isolated and located well away from sleeping areas with some forethought. The bigger boilers are a different animal. However awkward it is, try to view and hear one of these systems before you buy.

At the current time we have a hydronic system, an air blowing system, two oil-filled rads, and a plug-in electric blower heater. We use all of them at different times, but mostly the plug in stuff when on shore power, and the diesel powered systems when not. And in the middle of winter, probably due to the phenomenal heat loss from a boat, we sometimes use nearly all of them together! And we have an electric blanket. And in extreme winter, hot water bottles too.

So, like most year round yachties, we have many different ways to keep warm. There doesn't yet seem to be one solution that will do everything all the time. We have good friend who has spent much time insulating the empty spaces in his boat and this certainly seems to help but I wonder if there is any disadvantage wfrom the loss of air cirulation.


Cheers

Garold
 
Wallas hot air heaters are considerably quieter than eberspacher type heaters.

Having said that I replaced mine with a Mikuni which has a silenced exhaust and on a 34' boat doesn't make much noise, well none that bothers me. Very rarely have heating on at night, that's what duvets are for.:)
 
Garold.....

Thanks for the info, it's surprising how much you forget after 40 years of designing heating systems :)

Tom

Tom

Just giving a consumer's point of view. My info/experiences were intended for the the OP.

If you've been fitting heating systems to boats for over 40 years, then I may sail round to you next time I have one fitted because clearly I've not found 'boat heating nirvana' yet.

Cheers

Garold
 
heating nirvana requires the builder to think about insulation and proper heating during design. retrofit is going to be 'good enough' at best.

you have two choices - commission your own boat, or sail south.
 
heating nirvana requires the builder to think about insulation and proper heating during design. retrofit is going to be 'good enough' at best.

I think that's overly pessimistic; while retrofitting insulation is not straightforward, it should be possible to get a better result than 'good enough' without ripping the whole interior out or breaking the bank. Modern insulation materials are vastly improved and easier to apply than of old; once insulated, you then benefit from not paying to heat the world as well as your saloon.
 
While I agree with the negatives of air heaters, they are somewhat offset by the big positive (for me at least) which is constant flow of fresh air into the cabins.
 
There is no reason for a hot air system to be obtrusive, either inside or outside the boat, a properly planned install using the correct mountings, exhaust silencing and for the interior a trunking attenuator can and does reduce the noise massively. All that said, for some time now I have leant toward (again a properly planned) wet sysyem for anything over 40' it can be difficult siting radiators but stuff like Kalori range of finned axial fan assisted units make that much easier, use the fan to boost and switch it off or right down for a quiet sleep. Really as with most things it comes down to cost and all most people want is cheap, not best. Wallas, though I am and agent for them are not good with long duct runs in larger boats, it's not what they are designed for. Correctly heating a boat is not about ripping an Ebo or Webo out of a BT van and bunging it in a boat, it's down to planning and cost as there are so many variable both in boats and products available, the big two hardly scratch the surface of available solutions and even then have a wider product range within their portfolio that many people realise.
 
One thing with the hot air heaters is that they introduce new, dry air into the boat so very good at keeping things dry & as a couple of others have said, silencers are available. But they do require maintenance and parts are expensive. I had one but now use oil rads and electric blanket. Drip feed diesel heaters are good but heat too localised for a bigger mobo, though can also heat water/rads, see here...
 
To Paul Sallis

I spent £xk on an eberspacher.

If its heating in a marina on shore power you want one or two oil filled electric rads at about £40 each and a fan heater at about £30 may do the job for £110 total

or buy an eberspacher at £xk?

Its worth a try?
 
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