Diesel/electric heating

[winfarthing]

With planning to spend more time onboard, and being keen on comfort, I'm hoping to fit an integrated heating system on the Colvic Victor 40 I'm refitting. In marinas it would be senseless to run a diesel heater, making noise and fumes, when electric heating could be used. I realise amps can be limited so not looking to achieve tropical conditions. I have thought of putting in the usual Eberspacher or equivalent with separate ducted electric air heating. Even better would be a combination of the two using one set of ducting. I'm sure I'm not the first person to ponder this. Has anyone gone down this road? Is there a ready made product out there? Any better ideas? I'm an ex marine engineer so well able to make something up if no such system exists.

 

[Vara]

It's something I've been toying with, as heating a boat with domestic electric heaters always leaves cold corners unless you use lots of them, which is a pain.

Ducted heaters do exist, arguable as to whether normal eber/webo/Mikuni ducting would be adequate, but I'm sure with a bit of money thrown at it the problem could be solved.

http://www.vent-axia.com/product/airtrack-duct-air-heater-controls.html

 

[winfarthing]

It's something I've been toying with, as heating a boat with domestic electric heaters always leaves cold corners unless you use lots of them, which is a pain.

Ducted heaters do exist, arguable as to whether normal eber/webo/Mikuni ducting would be adequate, but I'm sure with a bit of money thrown at it the problem could be solved.

http://www.vent-axia.com/product/airtrack-duct-air-heater-controls.html

Looks interesting. Have to find some way to interlock it to the diesel heater on vent only to ensure supply of air and cool down period. Thanks.

 

[KevB]

What about one of these..

http://shop.sterlingauto.co.uk/whale-sh2202-internal-gas-and-240v-space-heater-363-p.asp

 

[winfarthing]

What about one of these..

http://shop.sterlingauto.co.uk/whale-sh2202-internal-gas-and-240v-space-heater-363-p.asp

That's very interesting, I wonder how much gas it uses. Can't see that info on Whales website. Off course, we can carry large quantities of diesel and it's easy to get. Bit different with gas though. Worth considering though, the price alone is half of an Eber.

 

[Stemar]

Also look at Propex if the idea of gas doesn't scare you off. http://www.propexheatsource.co.uk/heaters/hs2000e

Consumption figures:
HS2000
Average consumption 142 grams/hour
3.9kg propane cylinder 27.5 hours
4.5kg butane 31.7 hours
13kg propane 91.5 hours
15kg butane 105.6 hours
19kg butane 133.8 hours
47kg butane 331.0 hours
904 Camping gaz (1.81kg) 12.75 hours
907 Camping gaz (2.72kg) 19.0 hours

These figures assume it's running continuously. In practice, I reckon you'd double the bottle life unless it gets really cold.

For comparison, an Eberspacher D2 burns around 1/4l of diesel per hour for the same power output. it uses a little more 12v power when running, but quite a bit more during ignition, as there's a glowplug to run, rather than just a spark generator.

 

[duncan99210]

Winter liveaboard, albeit in the Med, we find that a domestic fan heater provides more tha enough heat in the boat. We have an Ebers and do the sums each winter to decide which is cheaper to use for heat. Sometimes the Eber is cheaper, others it's the fan heater. We find little difference in terms of outcome except that the Eber is better at keeping condensation in check as it brings in air from outside. Also, a domestic fan heater is cheap as chips to buy.... If we were starting fro scratch now, we'd think long and hard about the Eber as the initial cost was high, probably higher than the savings we've made over the fan heater running costs.

 

[Boathook]

What about one of these..

http://shop.sterlingauto.co.uk/whale-sh2202-internal-gas-and-240v-space-heater-363-p.asp

The whale unit is a rebadged propex. I purchased a propex HS200 (gas only) last weekend from the manufactures (caught them in the office doing paperwork!) They have some link with Whale now hence the Whale badging I assume. Just got to install it which will hopefully be starting this weekend. I know that I should have done this in the winter .................

 

[Marsupial]

Beware of AVERAGES

Also look at Propex if the idea of gas doesn't scare you off. http://www.propexheatsource.co.uk/heaters/hs2000e

Consumption figures:
HS2000
Average consumption 142 grams/hour
3.9kg propane cylinder 27.5 hours
4.5kg butane 31.7 hours
13kg propane 91.5 hours
15kg butane 105.6 hours
19kg butane 133.8 hours
47kg butane 331.0 hours
904 Camping gaz (1.81kg) 12.75 hours
907 Camping gaz (2.72kg) 19.0 hours

These figures assume it's running continuously. In practice, I reckon you'd double the bottle life unless it gets really cold.

For comparison, an Eberspacher D2 burns around 1/4l of diesel per hour for the same power output. it uses a little more 12v power when running, but quite a bit more during ignition, as there's a glowplug to run, rather than just a spark generator.

Something is wrong here, energy density for propane is 12.9KW per kilo and 11.9 KW per kilo for diesel so 142grams of propane is nothing like the same heat equivalent of 250 grams of diesel. The comparison is not genuine something to do with "average" in one and flat out in the other perhaps.

 

[Colvic Watson]

Eber make an electric eber.

 

[mjcoon]

Something is wrong here, energy density for propane is 12.9KW per kilo and 11.9 KW per kilo for diesel so 142grams of propane is nothing like the same heat equivalent of 250 grams of diesel. The comparison is not genuine something to do with "average" in one and flat out in the other perhaps.

"KW" is power not energy. Did you mean "kWh" which is a measure of energy? (Sorry, I can't be bothered to look numbers up in my Kaye and Laby even though it is in reach.)

Mike.

 

[Marsupial]

"KW" is power not energy. Did you mean "kWh" which is a measure of energy? (Sorry, I can't be bothered to look numbers up in my Kaye and Laby even though it is in reach.)

Mike.

Mike, IF it makes a difference to you then yes its KWH but in any event the comparison as listed is spurious. AND if you want to include Butane then its 13.69KWH per kilo. In the end it comes down to difference in cost per KWH for gas Propane or Butane vs Diesel, in our market Diesel wins every time.

 

[LadyInBed]

I have a propex but I hardly ever use it.
In marinas I use my mains fan heaters, a 2kw in the saloon but that is too hot, so I use it on the 1kw setting. Forward and aft cabins have 1kw fan heaters, they are all very small and are screwed low down to vertical surfaces where they won't get kicked.
Also have cylinder frost heaters on thermostats, one in the engine bay and one in the saloon.

 

[winfarthing]

I have a propex but I hardly ever use it.
In marinas I use my mains fan heaters, a 2kw in the saloon but that is too hot, so I use it on the 1kw setting. Forward and aft cabins have 1kw fan heaters, they are all very small and are screwed low down to vertical surfaces where they won't get kicked.
Also have cylinder frost heaters on thermostats, one in the engine bay and one in the saloon.

Thanks for all above info, all seriously considered. Having looked hard at the gas/electric heater, I'm not sure it's 2kW output would be sufficient for a 40' boat with separated out accommodation. I had also been considering a Wallis oven in a bid to do away with gas and be a one fuel vessel. Only fly in the ointment there is the staggering cost and some not too good reviews about reliability.
I think the Vent Axia electric heater would be a better unit if it had an integral fan. I'm erring on the side of separate diesel and electric ducted heating systems to keep things simple.

 

[LadyInBed]

I'm erring on the side of separate diesel and electric ducted heating systems to keep things simple.

I might have misread this, but if you are going to run ducting, it would be good to use a common duct for both sources.
How much time will you be using heating at anchor / sailing to use in a marina?
For me, it's mostly marina as at anchor there are less distractions, so I go to bed earlier.
In a marina I think electric fan heaters are the most effective heating. They are easier to control, especially if on thermostats, or turn up, down, off than adjusting vents on a duct, and the heat that comes out at the end of the duct run isn't very hot.
My 2kw Propex will only serve the saloon and aft cabin (on a 10m boat), too much heat loss for it to get to the fwd cabin.

 

[David2452]

Have you considered a wet ststem, much easier to incorporate diesel and electric. One thing is for sure, unless you are being seriously ripped of for electricity it is the most economical method and quiet too

 

[mrplastic]

If you are going to install a standard eberspacher system then why not fit an eberspacher Airtronic unit too? This is a mains driven heater that fits inline directly after the diesel unit. A special loom is available that detects if mains is connected and switches to the Airtronic automatically. Saves installing a completely separate system!

 

[David2452]

If you are going to install a standard eberspacher system then why not fit an eberspacher Airtronic unit too? This is a mains driven heater that fits inline directly after the diesel unit. A special loom is available that detects if mains is connected and switches to the Airtronic automatically. Saves installing a completely separate system!

Unfortunately the Eberspacher heaters are not man enough for the OPs requirements at at 1 to 2 Kw when powered by 240v, a really good concept but inapropriate in this case.

 

[winfarthing]

Have you considered a wet ststem, much easier to incorporate diesel and electric. One thing is for sure, unless you are being seriously ripped of for electricity it is the most economical method and quiet too

What system would you recommend? I haven't managed to find a wet system powered by diesel or electric.

I also didn't realise Eber did a combined system, pity it's under powered for me, sounds ideal.

Again, thanks for all input so far.

 

[robertj]

Eber hydronic is a wet system which can be combined with your engine to either preheat it before starting. I'm not sure if when under engine you can heat the radiators of the system. Also via a calorfier heats the domestic hot water.