Gas or Diesel Air Heaters

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stownsend

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Hello

Has anyone got any views on either has or diesel powered hot air heaters, looking at a boat with a gas heated air blower, but also considering a boat with none so would fit a diesel. Looking at the specs on both diesel appear to be more efficient, ie 100 to 250 ml of fuel per hour compared to 17 hours with a 8 kg gas cylinder.

Cheers

Stu
 
Diesel would be my choice too, you will be forever changing out the gas cylinders if you go with a gas heater even if you have a 13kg one, it doesnt last long, If i was redoing my heating again, i would go with an eberspacher again, instant heat and plenty of it when you need it and easily turn off and onable
 
stownsend said:
Hello

Has anyone got any views on either has or diesel powered hot air heaters, looking at a boat with a gas heated air blower, but also considering a boat with none so would fit a diesel. Looking at the specs on both diesel appear to be more efficient, ie 100 to 250 ml of fuel per hour compared to 17 hours with a 8 kg gas cylinder.

Cheers

Stu
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gas burns clean fan is quiet but gas is very expensive compared to diesel
 
The paraffin models are somewhat cheaper than diesel. Any views, apart from the need to carry another type of fuel, albeit in rather small quantity? Will they run on kerosene home heating fuel?
 
Keroscene is paraffin is TVO is Airbus fuel-OK some is better refined and cleaner than others but all have been put to the same uses.
Diesel powered heaters are very expensive to buy and if they go wrong they are equally very expensive to fix!
To me gas is more expensive but unless you are live aboard its more convenient in my opinion.
13 kg gas bottles last me three weeks or so on my 4 kw space heater at home.
 
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Thanks ffill. I have an old Ardic heater I am looking to replace as cheaply as possible. The ducting is all there so I only need to replace the heater unit. The paraffin looks attractive due to its lower initial cost and lower electrical power draw. I use kerosene for home heating so supply is sorted. A relatively small tank in a locker should cope with the fuel quantity needed. Interested to hear from anybody using a parraffin webasto type unit or similar.
 
A great deal depends on your expected pattern of usage. As others have said, gas is the cleanest and most reliable followed by parafin and then diesel. If you are just looking for short periods of heating in spring and autumn, gas is probably best. If, like us, you use the boat all year round, then you cannot winterise it and will need full-time heat to make it liveable and protect it from freezing. Diesel is probably the only option - mainly because the boat probably has a large tank of diesel for you to burn.

Over the last few weeks since Christmas, we've been on the boat a lot of the time, and the Webasto has been on continuously. When we've been on board it's been running pretty much flat out and when we are away for any length of time we turn the thermostat down low. In the last four weeks, with temperatures dropping to -5 at times and below zero most of the time, we've got through over a hundred litres of diesel - in gas or parafin it would have been impossible...
 
Power consumption is only higher on diesel burners at start up and for a very short time, any blown air heater after that is only driving a fan and a fuel pump unless drip fed or LPG, the majority of the consumption even then goes into the fan. The only reason some heaters use less power at that stage is because they move less air and are therefore not as good at heating a volume against the back pressure of a duct run, Wallas are a case in point, great heaters but don't assume they have the same CFM delivery as similar BTU Webo Mikuni or Ebo, they do not, that is not a criticism of Wallas, they are great but properly heating a boat whilst using minumum power is not about simply choosing the lowest electrical consumption quoted in the brochures. With the right planning of furnace site, properly lagged distribution duct, properly ballanced and sized to increase velocity, it's surprising just how small a furnace you can use.
 
saltylegs said:
I am fitting a Propex LPG.
lower noise, lower power consumption, lighter and I work for an LPG supplier so get it at half price:D
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I fitted a Propex to a boat in about 1994. I have seen the same boat for sale not long ago and the Propex is still working. It was an excellent heater. Even though we were on an exposed swinging mooring and fuelling by small Calor butane bottles we didn't find the cost and inconvenience to be a major problem.

Safety is no more of an issue than with a gas cooker, and it could be argued is better. The heater has several permissives that will not allow the gas to turn on unless all is well.
 
Thanks for the replies, we may go for one without any heating so any preference on diesel heaters, Eberspacher or Webasto, any other makes ?

Cheers

Stu
 
stownsend said:
Thanks for the replies, we may go for one without any heating so any preference on diesel heaters, Eberspacher or Webasto, any other makes ?

Cheers

Stu
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Well, my experience of diesel heaters is limited to a brand new Webasto that has worked very well for us, but there would be no excuse for it doing anything else. We have the Airtop 3900 fitted on a 33 foot Jeanneau and the local Webasto main dealer told us he regarded it as overpowered for that size boat, but in the recent cold weather it was running flat out to keep the boat at a decent temperature, so I don't think that anything smaller would be adequate.

A plumber friend of ours has an Eberspacher on his yacht which broke down a couple of months ago and has driven him nuts. I know that he is a very competent engineer, so the fact that he has had so much trouble getting his Eber running again must mean something!
 
stownsend said:
Thanks for the replies, we may go for one without any heating so any preference on diesel heaters, Eberspacher or Webasto, any other makes ?

Cheers

Stu
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Have a look at Wallas. Designed for marine use, unlike Webasto & Eberspacher which were designed for trucks.
 
zikzik said:
Have a look at Wallas. Designed for marine use, unlike Webasto & Eberspacher which were designed for trucks.
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They are all designed for heating a space and don't care whether that space is in a boat, truck or crane or RV, if anybody can tell me how a heater knows whether the space it's heating is in a boat or an ambulance I would be glad to hear it. In fact one of the important things about when planning a boat install (assuming a decent house bank) is that a heater should be able to cope with the back pressure from long trunking runs, something that the Wallas (great heaters though they are) doesn't exactly excell at due to the pre occupation with saving amps. The Webasto "boot" heater actually has increased fan pressure for this but I confess to only ever seeing one of these and that was at a Webo technical seminar.
 
I have a Eberspacher unit fitted in a van I use on a regular basis, agree the unit does not know what it is heating as I have never told it. It is a bit noisy on start up, once it is up to temp it is fantastic.
 
David2452 said:
the back pressure from long trunking runs, something that the Wallas (great heaters though they are) doesn't exactly excell at due to the pre occupation with saving amps.
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I agree. When I first investigated installing heating I discussed what to buy with a man who installed all types in trucks and boats. His view was that there was little to choose between Webasto and Eberspacher for performance and reliability but that Wallas was poor on delivery of the heated air.

Mikuni seem to have come on well but I was advised to check the spares availability in Europe (I was living in Holland at the time) as they had fewer agents there.
 
We had an Eber on our last boat and it was adequate. On this boat we have a Wallas which is hugely superior:
- much quieter
- about half the fuel consumption
- no wasted heat (the exhaust is cool, the Eber's exhaust would melt fenders!)
- easier to use.
We've only had the boat for 10 months, so can't comment on reliability or spares.
 
One thing to consider if going down the gas route, ours is lovely but if you're running it on butane and the temperature outside is in single figures after a while of running the temperature at the bottle drops below the point that it gasses off and the heater stops working. :(

Works fine in the summer though! :cool:
 
Use propane its slightly cheaper too, or fit the 30mbar reg and use butane in summer and propane in winter.
I am also installing a quick fit connection in the cockpit similar to a BBQ connection point so I can install a larger cylinder with its own regulator at the back of the cockpit or on deck for winter use.
 
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