Diesel heater blower v electrics

[Boeingdr]

I am considering fitting a simple 1 or 2 outlet diesel heater to my 26ft yacht. Ebber or similar.
I have 2x12v 120ah batterys purchased this year an alternator from yanmar gm20 diesel engine but no charger from shore power.
Does anybody know what the typical battery drain would be on start and running.
Would I need a mains charger to keep batteries charged.

 

[fireball]

The old Eber D1LC takes 20Amp on start up - and similar on shut down - this is only brief and then cuts down to a more respectable lowmid single figure drain ... the newer units are less power hungry ...
We have a Yanmar 2GM20 and normally swing about with no shore power - and you have a bigger battery bank than I do ...
Should be fine - but might need 1/2hr on the engine if you're using the heater for long.....

 

[Boeingdr]

Thanks fireball, sounds like my project for the next few weeks then.

 

[savageseadog]

Use some decent size cable to power it. Something like 6mm or 10mm square

 

[Talbot]

use bimetal hole saws and a really good drill for the trunking cut outs, as It puts a fierce load on them. I burnt out a drill fitting my system.

 

[Pye_End]

The new ones I think take 8A on start-up for a couple of minutes, and at full welly take something lik 2A, although 1/2 an hour of this and you will probably be under 1A.

If we are on to general installation advice -

lag the ducts unless you want your lockers heated

If your exhaust pipe is near your fenders / rope etc. like mine - lag it, lag it again, and put some more ducting over the top etc. - I'm sure you get my drift - it can get very hot. Just done this job and prbably easier to do when you are putting it together.

 

[mikejames]

Webasto are similar : about 12 amps and then go down to 1 amp. Half an amp with the fan ticking over.
I ended up fitting 20mm2 cable as the battery was 3 metres away from the power take off for the heater. Without that thick cable I could only start the heater about 3 times on a fully charged battery before it refused to start again.

I used a ratchet socket spanner to drive the hole saw for the ducting as I didnt have any AC power when I fitted the heater.

Worst was cutting a hole in the fuel tank for the fuel pickup. 25mm hole took about 2 hours to hand drive the hole saw.

I agree with the comment on lagging : fortunately my exhaust goes such a short distance I was able to double lag the hose with the provided glass lagging.

For the hot air I used central heating neoprene lagging tape from B&Q : it has survived several years and cooled down the lockers when I installed it. My fenders like me better too.

 

[Heckler]

have a 56 watt solar panel now and the first thing that goes on when i enter the boat is the frdge for the cold beer, then the eber if it is cold, i have 3 85 amp hr batteries and i dont have to start the engine all weekend to make sure that all is well.

 

[PeterGibbs]

Power consumption for a rig such as you describe will not be a problem, assuming you run the heater now and then for 2-4 hours at a time. Naturally you will attend regularly to the state of your batteries.

Other responses have touched on more serious issues:

1. The unit - Eber or Webasto (which I have) do make a certain level of running noise - bit like a paint stripper - not easy to sleep over the top of that when it is running, so where do you site it so it also has space to stay cool? (Combustion air intake should be provided via exhaust pipe)

2. And how will the air ducts be run to their destination- a site some way from the heater intake point so you get warm air circulating all around the boat back to the heater intake? Drilling 10cm holes through bulkheads and other furniture is tough going and a real case of "measure 3 times and drill once!"

2. Exhaust pipe will get very hot and require proper insulation (glassfibre or the like) all the way to the outlet. Choose an outlet spot (normally the transom or nearby) where waves do not approach - you do not want water entering the system, so space for a swan's kneck has to be provided.

4. Tapping into the diesel tank is a lot of fun: simple in principle but capable of generating real problems in operation. Can you enter it from the top? If not, take lots of advice before you start drilling! You might have to lead off a spur from the line feeding the engine. This could be the bit best left to your engineer.

I really go for my diesel heater - a great investment: have fun!

PWG