heaters

dunmor

dunmor

Well-Known Member
Joined
26 Jul 2009
Messages
600
Location
sovereign harbour east bourne
Visit site
Would have thought the size of battery bank needed to run a fan heater via an inverter would be prohibitive. How about a vapalux/tilley pressure lamp or Origo Heatmate? There was recently a very lengthy thread about heating a small boat...
 
Well, you mention a 1500W inverter so I imagine that you are considering a small 1kW heater. You'd need to make certain that the inverter was rated for 1kW continuous use. Many say 1500W but small print might say "for up to 5mins.".

I assume that you know the inverter would pull at least 80-90A to run a small fan heater. You are likely to find that the alternator isn't up to producing this current continuously.

The waste heat from your main engine will dwarf the output from the 1kW heater.
 
Last edited:
it says 1500w peak 3000w. would this be ok if i put a better alternator on. the alternator only gives 55 amp i believe. wot about the microwave?.
Mistroma said:
Well, you mention a 1500W inverter so I imagine that you are considering a small 1kW heater. You'd need to make certain that the inverter was rated for 1kW continuous use. Many say 1500W but small print might say "for up to 5mins.".

I assume that you know the inverter would pull at least 80-90A to run a small fan heater. You are likely to find that the alternator isn't up to producing this current continuously.

The waste heat from your main engine will dwarf the output from the 1kW heater.
Click to expand...
 
dunmor said:
reading the thread on heaters made me wonder what size inverter i would need to run a small
fan heater in my wheel house whilst under way?. i have seen this one http://www.ebay.co.uk/itm/281022258134?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
on ebay, which doesn't seem a bad price for 1500watts. would it be enough, be handy if it could handle a
microwave as well. obviously it would run on the engine battery whilst running.
Click to expand...


Have a more careful look at that particular ebay advert. There is a note in the information suggesting it is for emergency use only and not intended for continuous use. So perhaps that is why it is agood price.
 
MartynG said:
Have a more careful look at that particular ebay advert. There is a note in the information suggesting it is for emergency use only and not intended for continuous use. So perhaps that is why it is agood price.
Click to expand...

It also has a strange mention of Overload Protection: 1000W-1100W, wonder what that means? I'd say it's not good value, as it would probably give up the ghost fairly rapidly.
 
I suspect it wouldn't be a cheap modification anyway and the invertor would be the least of your worries.

Wiring from alternator would probably need to be upgraded. You'd need a meaty hot-rated alternator to run at these levels for long periods. Your present alternator probably only puts out no more than 20-30A for 30 mins. on most days before dropping to 10-20A (rough guesstimate). Big jump to putting out 80-90A for long periods (more if you'd like to charge batteries at the same time).

You might also run into belt wear problems as 100A is close to the suggested limit for single V type belt drives.

The annoying part is that your diesel is probably wasting about 10kW (depends on size & type obviously) of heat and a small part of that would solve your heating problem when engine running. I haven't seen a matix heater (similar to one in your car) for use with marine engines. Perhaps someone else has. I suspect it would be expensive and a stove/heater would be better as you could run it without the engine.

You asked about a microwave. Less of a problem as these are only run for minutes instead of hours. Unfortunately, microwave cookers run less efficiently on cheap inverters so cooking times are extended (assuming it works at all).

I didn't look at the eBay inverter closely as I realised that it would only be part of your solution. I must say it does look odd that they show a car-lighter type connector (only good for 150-180W output) and battery clips with quite thin wires. Specs. do look odd as well (e.g. fuse sizes)
 
Last edited:
pvb said:
Loads available, see Kuranda's website ( http://www.kurandamarine.co.uk/kalori-heater-matrix/kalori-heater-matrix-12v ) or Mikuni's website ( http://www.mikuniheating.com/results.cfm?category=23&secondary=15 ) for examples. Not too expensive either.
Click to expand...

A matrix heater is the way to go as suggested above. I have a Silencio matrix heating the fore-cabin (from a Hydronic unit) and it works well; it's very quiet on the slower speed setting and quite acceptable on high.

If you have a calorifier already fitted you could just re-route the hot pipe from the engine through the matrix and then on to the calorifier. 16mm rubber heater hose works well. You could install the whole thing for around £150 and the heat is then 'free'!.
 
The OP is in the car trade - how about installing a car heater matrix and controls etc. An oldish car would be two speed fan/cable for hot to cold.
 
Matrix heaters do look reasonably cheap for ~2kW output vs. cost of Eber's etc. I expect you'd need to switch between calorifier and heater or balance the flow between them. Perhaps you could have a diverter to take heater output from calorifier input or output as required. That might give you quick hot water and a little heating on a cool day and other way around in cold weather.

Anyway, it sounds as if there's plenty of experience in the forum. I haven't looked at them because my boat came with a 5kW Webasto. My problem in Spain is how to get hot water without running the engine or generator (present solution). Pity the boat didn't come with a hydronic system and these matrix heaters. That would have given me hot water whenever it was needed.
 
Last edited:
Probably a much better idea than a sep. inverter (though you can use that for other things). I discounted these ages ago because my mains one runs well from the generator (so no inverter needed). However, they were very expensive at around £300 when I last checked. Have they dropped in price so that they are now a better buy than a decent inverter + cheap mains microwave?
 
I use a matrix (from a Ford Transit), tapped into the line to the calorifier. A 3" in-line fan, and some Eber ducting. Toasty.
 
On boats here a car heating units from buses and such were in use, a friend installed one from VW van.
Webasto kind.
Or indeed matrix unit on mobo.

When engine often in use - also extractor fan (the kind of bilgeblower) taking hot air from engine room, which usually happens to be close at hand for wheelhouse. Provided the engine is kept clean and smelling nice :)

The best heater I recall was air cooled diesel, with huge fan on flywheel. Had a way of diverting the blow to the cabin. Tornado inside, got boat dried in a minute :cool:
 
You must log in or register to reply here.

Share this page

Top