Gas Fridge

[cereal tiller]

Having recently installed a 3 way fridge, i wondered how many are around in boats.

 

current boat is the third one in 40 years,the 2 previous ones had 3 way fridges so now boat number 3 is so equipped.

 

When new this boat had a 240 v. fridge freezer,but, as diesel costs nearly 5 times more than it did 15 years ago i decided to revert to the 3 way.

 

100 watt continuous on shoreline costs around 40 pence a day,not too bad

 

Rough estimate,the fridge will us a 13 kg. cylinder of propane in 30-40 days depending on ambient temperature,30-40 pence a day,day being 24 hours

 

Any one worked out the costs of the 3 types in common use?

 

12 volt

 

240 volt

 

gas

[eightpot]

Got a three way fridge. Gas when cruising and 240v when in the marina on shoreline. I didn't bother connecting up the 12v side as it will not chill the fridge down from ambient and would make a large hole in my charging regime. A 13kg bottle will last about three weeks - that includes all cooking and water heating - so I think you're pretty much spot on there. On 240v, I'm burning about 20p of electric per day - again that also includes a 20amp battery charger, phone charger and laptop as well and the fridge, which is the ubiquitous Electrolux RM212F.

[MtB]

Any one worked out the costs of the 3 types in common use?

 

12 volt

 

240 volt

 

gas

 

 

Nope!

 

Mainly because it's just background noise compared to the major costs in running a boat.

 

MtB

[cereal tiller]

 

 

Nope!

 

Mainly because it's just background noise compared to the major costs in running a boat.

 

MtB

 

Not sure that it is a modest expenditure?

 

gas fridge 40 pence a day

 

From college days i recall that diesel engines are around 33 % efficient

 

alternators are roughly 40%

 

Inverters are 80-90% efficient with power conversion from 12 to 240 volt

 

I reckon the 240 volt fridge was costing one pound fifty a per 24 hour period in diesel

 

so,the gas fridge is saving a pound per 24 hours

 

as the boat is away from shorepower for at least 250 days per annum i think that it represents a considerable saving?

CT

[MtB]

 

Not sure that it is a modest expenditure?

 

gas fridge 40 pence a day

 

From college days i recall that diesel engines are around 33 % efficient

 

alternators are roughly 40%

 

Inverters are 80-90% efficient with power conversion from 12 to 240 volt

 

I reckon the 240 volt fridge was costing one pound fifty a per 24 hour period in diesel

 

so,the gas fridge is saving a pound per 24 hours

 

as the boat is away from shorepower for at least 250 days per annum i think that it represents a considerable saving?

CT

 

How much is your licence, tri-annual blacking, mooring charges and the 'opportunity cost' (i.e. what else could you do with the capital) of owning a boat?

 

MtB

[cereal tiller]

 

How much is your licence, tri-annual blacking, mooring charges and the 'opportunity cost' (i.e. what else could you do with the capital) of owning a boat?

 

MtB

 

Licence 830 squids

 

moorings 3.5 K

 

blacking 300-400 every 4 years

 

I suppose i could release the capital locked up in the boat by selling it,but, i would probably then spend most of my disposable income on "Wine women And song"

 

actually.................

[MtB]

 

Licence 830 squids

 

moorings 3.5 K

 

blacking 300-400 every 4 years

 

I suppose i could release the capital locked up in the boat by selling it,but, i would probably then spend most of my disposable income on "Wine women And song"

 

actually.................

 

 

And then waste the rest!

 

...to paraphrase George Best.

 

RIP

 

 

MtB

[Ex- Member]

 

Licence 830 squids

 

moorings 3.5 K

 

blacking 300-400 every 4 years

 

I suppose i could release the capital locked up in the boat by selling it,but, i would probably then spend most of my disposable income on "Wine women And song"

 

actually.................

 

Solar is probably the cheapest option for an off grid boat now. For 4 months of the year we need to compensate for lack of day/sunlight. The shortfall averages £1.60 per day for 120 days in additional generation costs. so then divide £192 divide by 52 weeks = £3.69 per week, so cost per day 53p p for our leccy, and we're quite heavy users.

 

The cost of solar installation isn't included in that, but that cost is far outweighed by reduced engine running costs and wear & tear over the lifetime of the solar panels.

 

Having said that the one off cost of solar will also be spread over 20 years. Our solar installation cost £1200 for everything. Basically £17p per day, but as stated fully recouped anyway.

Edited December 30, 2013 by Julynian

[cereal tiller]

 

Solar is probably the cheapest option for an off grid boat now. For 4 months of the year we need to compensate for lack of day/sunlight. The shortfall averages £1.60 per day for 120 days in additional generation costs. so then divide £192 divide by 52 weeks = £3.69 per week, so cost per day 53p p for our leccy, and we're quite heavy users.

 

The cost of solar installation isn't included in that, but that cost is far outweighed by reduced engine running costs and wear & tear over the lifetime of the solar panels.

 

Having said that the one off cost of solar will also be spread over 20 years. Our solar installation cost £1200 for everything. Basically £17p per day, but as stated fully recouped anyway.

Agreed

 

will be taking the Solar route next spring,it has now become economicaly viable.

 

looking forward to being on a mooring for more than one day without having to charge batteries by genset or main engine.

 

CT

[Mac of Cygnet]

, tri-annual blacking,

 

MtB

 

Isn't it a bit of a hassle taking the boat out three times a year just to black it?

 

Wouldn't have bothered, but you are a stickler, Mike.

[Ex- Member]

Agreed

 

will be taking the Solar route next spring,it has now become economicaly viable.

 

looking forward to being on a mooring for more than one day without having to charge batteries by genset or main engine.

 

CT

 

Agreed

 

will be taking the Solar route next spring,it has now become economicaly viable.

 

looking forward to being on a mooring for more than one day without having to charge batteries by genset or main engine.

 

CT

 

Well it's served us extremely well. The figures I stated are based on the past 2 months, I have to admit to laziness in not getting the generator out in November, had I have done that the £1.60 cost quoted would have been much reduced as we were running the boat engine, and clocked ofer 30 hours where we should have been running a small generator which costs just 46p per hour in petrol.

 

We're logging costs to the End of Feb when we should be completely solar sufficient again, possibly an odd day here and there in the first month, but we survived the whole of October on solar alone so think March will be the same. Well see!.

 

I posted some graphs on another thread.

 

ETA here http://www.canalworld.net/forums/index.php?showtopic=61899&page=2

Edited December 30, 2013 by Julynian

[cereal tiller]

 

 

Well it's served us extremely well. The figures I stated are based on the past 2 months, I have to admit to laziness in not getting the generator out in November, had I have done that the £1.60 cost quoted would have been much reduced as we were running the boat engine, and clocked ofer 30 hours where we should have been running a small generator which costs just 46p per hour in petrol.

 

We're logging costs to the End of Feb when we should be completely solar sufficient again, possibly an odd day here and there in the first month, but we survived the whole of October on solar alone so think March will be the same. Well see!.

 

I posted some graphs on another thread.

 

ETA here http://www.canalworld.net/forums/index.php?showtopic=61899&page=2

 

It might not be very long before solar/diesel propulsion installations become common on inland waterways craft.

 

It did cross my mind that utilising dean/doodlebug loogic(deliberate spelling),the solar panels could be occasionaly mounted to catch a favourable breeze and assist in the boat's forward motion?

 

 

 

On wider reaches of rivers only!

 

It might not be very long before solar/diesel propulsion installations become common on inland waterways craft.

 

It did cross my mind that utilising dean/doodlebug loogic(deliberate spelling),the solar panels could be occasionaly mounted to catch a favourable breeze and assist in the boat's forward motion?

 

 

 

On wider reaches of rivers only!

 

Mike the boiler,i reckon that it could save another 20 quid a year,but the rustle of the wind would make a nice "background noise"

[Paul C]

Do these things have flame failure device? That would be my main concern - leaving a flueless gas appliance on all the time, even while asleep and while the boat is unattended for brief periods. Being in a boat poses particular challenges if a leak occurred, for getting the gas out again.

[Robbo]

They say a average 12v fridge uses around 50 amp a day. For me to generate that at 80% battery efficiency would cost around about half a litre of diesel. So around 40-45p. On shoreline it would be around about 9p.

 

Someone here mentioned a 240v fridge using 117kwh a year ?

 

That's the equivlent of about 32ah a day at 12v with using a 80% efficient inverter.

Edited December 31, 2013 by Robbo

[MtB]

Do these things have flame failure device? That would be my main concern - leaving a flueless gas appliance on all the time, even while asleep and while the boat is unattended for brief periods. Being in a boat poses particular challenges if a leak occurred, for getting the gas out again.

 

Yes they do.

 

And the flame size is about the same as the pilot light on a Morco, which is why they are designed as flueless appliances.

 

Adding a flue is pretty pointless as the amount of flue gas emitted is microscopic. The main reason for adding a flue is because boaters tend not to service their gas fridges leading to spiders' webs, pet hair, fluff etc blocking the air supply to the gas flame and/or gasway and flue, which in turn causes CO production. Under which circumstances a flue isn't going to be a whole lot of help anyway but it lets the punters feel better about it.

 

If you run a gas fridge, annual (or more frequent) servicing is essential until you get a feel for how often it accumulates crap around the back.

 

Paul makes a good point about gas leaks. 'The regs' say to install gas pipe runs as high as practicable (or some similar phrase) in the boat. This is to maximise the chances of you smelling a gas leak should one occur as LPG is a lot heavier than air and just flows straight down into the bottom of the boat. The flame in a gas fridge has to be at the base of the fridge for it to work, i.e. near the floor.

 

My advice would be to install a gas fridge at worktop level, in something like an eye-level oven housing, making sure there is a clear worktop in front of it so it becomes easy and practical to pull it out onto the worktop for servicing/pilot light cleaning, regular, like.

 

MtB

Edited December 31, 2013 by Mike the Boilerman

[MtB]

 

Isn't it a bit of a hassle taking the boat out three times a year just to black it?

 

Wouldn't have bothered, but you are a stickler, Mike.

 

No it's fine. I'm always wanting to learn.

 

So, given tri-annually means three times a year, what term means 'every three years'? On checking, I'm not there IS one...

 

 

MtB

[Robbo]

100 watt continuous on shoreline costs around 40 pence a day,not too bad

 

Rough estimate,the fridge will us a 13 kg. cylinder of propane in 30-40 days depending on ambient temperature,30-40 pence a day,day being 24 hours

 

 

Propane 13Kg is around £25, how did you work it to get to 30-40p per day if a cylinder lasts 30-40 days?

Edited December 31, 2013 by Robbo

[cereal tiller]

 

Propane 13Kg is around £25, how did you work it to get to 30-40p per day if a cylinder lasts 30-40 days?

 

Sorry about those figures,i was thinking of the boats total gas consumption

 

The tech data on the fridge is stated to be 9.5 grams per hour

 

use your calculator,the mainspring has broken on mine!

 

ETA. just worked out on paper,roughly 67 x 24 from a 13kg propane cylinder.so 37 pence per 24 hour period?

Edited December 31, 2013 by cereal tiller

[cereal tiller]

 

Yes they do.

 

And the flame size is about the same as the pilot light on a Morco, which is why they are designed as flueless appliances.

 

Adding a flue is pretty pointless as the amount of flue gas emitted is microscopic. The main reason for adding a flue is because boaters tend not to service their gas fridges leading to spiders' webs, pet hair, fluff etc blocking the air supply to the gas flame and/or gasway and flue, which in turn causes CO production. Under which circumstances a flue isn't going to be a whole lot of help anyway but it lets the punters feel better about it.

 

If you run a gas fridge, annual (or more frequent) servicing is essential until you get a feel for how often it accumulates crap around the back.

 

Paul makes a good point about gas leaks. 'The regs' say to install gas pipe runs as high as practicable (or some similar phrase) in the boat. This is to maximise the chances of you smelling a gas leak should one occur as LPG is a lot heavier than air and just flows straight down into the bottom of the boat. The flame in a gas fridge has to be at the base of the fridge for it to work, i.e. near the floor.

 

My advice would be to install a gas fridge at worktop level, in something like an eye-level oven housing, making sure there is a clear worktop in front of it so it becomes easy and practical to pull it out onto the worktop for servicing/pilot light cleaning, regular, like.

 

MtB

 

Yes Mike

 

The flame on my fridge is almost one metre above floor level,and the burner assembly can be accessed by unclipping a side panel

 

 

[Ex- Member]

They say a average 12v fridge uses around 50 amp a day. For me to generate that at 80% battery efficiency would cost around about half a litre of diesel. So around 40-45p. On shoreline it would be around about 9p.

 

Someone here mentioned a 240v fridge using 117kwh a year ?

 

 

That's the equivlent of about 32ah a day at 12v with using a 80% efficient inverter.

 

That would be us, our inverter's also 90% efficient according to the blurb, so even better. We have an ammeter fitted, what's strange is that when the fridge kicks in, which isn't very often, according to the meter it's drawing just 1 amp. When the fridge kicks in when the small Honda generator is running, it really affects the revs for a second.

 

I just don't understand the ammeter reading, for all other appliances we know the amps draw required, it reads pretty much correctly within 0.2.

 

If the fridge only pulls 1 amp sometimes 1.2 intermittently then it's not going to use anywhere 24 amps per day, which must be incorrect. I intend to investigate further. We do keep a pretty full fridge though, maybe this is helping.

[Robbo]

 

Sorry about those figures,i was thinking of the boats total gas consumption

 

The tech data on the fridge is stated to be 9.5 grams per hour

 

use your calculator,the mainspring has broken on mine!

 

ETA. just worked out on paper,roughly 67 x 24 from a 13kg propane cylinder.so 37 pence per 24 hour period?

 

From those figures I work it to be around 44p per day with 13Kg lasting 57 days. I've used £25 for a 13kg calor cylinder

 

That would be us, our inverter's also 90% efficient according to the blurb, so even better. We have an ammeter fitted, what's strange is that when the fridge kicks in, which isn't very often, according to the meter it's drawing just 1 amp. When the fridge kicks in when the small Honda generator is running, it really affects the revs for a second.

 

I just don't understand the ammeter reading, for all other appliances we know the amps draw required, it reads pretty much correctly within 0.2.

 

If the fridge only pulls 1 amp sometimes 1.2 intermittently then it's not going to use anywhere 24 amps per day, which must be incorrect. I intend to investigate further. We do keep a pretty full fridge though, maybe this is helping.

 

When the fridge motor kicks in it will cause a surge which more than likely not show on your meter as this will average it out. One way to see how much it's using is too switch everything off bar the fridge for a good period. Another major factor is how warm the surrounding area of the fridge is and how much ventilation at the back it has. Any fridge will benefit from additional insulation.

[raymondh]

Hi,

I thought it was not (BSS) permitted to fit new/replace a gas fridge in a canal boat?

quote from WW

 

"Gas fridges on boats have gone out of fashion. This is due mostly because the Boat Safety Scheme requires any new gas appliance to be installed according to the manufacturers instructions, and there is not a gas fridge available recommended for boats since Dometic withdrew their appliance.
Older private boats that had a gas fridge when the scheme came in are allowed to keep them,
however the problem comes when they need replacing"

 

Advice form BSS needed?

 

Ray

[Ex- Member]

 

From those figures I work it to be around 44p per day with 13Kg lasting 57 days. I've used £25 for a 13kg calor cylinder

 

When the fridge motor kicks in it will cause a surge which more than likely not show on your meter as this will average it out. One way to see how much it's using is too switch everything off bar the fridge for a good period. Another major factor is how warm the surrounding area of the fridge is and how much ventilation at the back it has. Any fridge will benefit from additional insulation.

 

 

AHH we have done this, but only to take the amp reading, we haven't left it like that for more than a minuet or so. We do have fans in the floor under the fridge, we don't run the fans in winter, but of course there's a gaping hole in the floor below the fridge motor, so cool air is naturally drawn through these holes, also assists good ventilation in the boat.

 

The fridge is so quiet as well it's hard to know weather it's running or not. Now when the genny is on, we know when it's kicked in at least as the engine note changes. In fact it's the only time we can here the generator, it's barely audible from the main saloon.

 

We have a very accurate clamp ammeter too, but isolating the single 240 live wire to the fridge is tricky.

 

 

 

 

Edited December 31, 2013 by Julynian

[Robbo]

My view....

 

The main plus point with gas is that although quite inefficient is that it uses what it uses there and then.

 

The down side with electric fridges (either 12v or 240v) is producing your own electric. To make it efficient you have to have the right size generator for your charger and then batteries. If any of these are way off then it's going to inefficient.

 

AHH we have done this, but only to take the amp reading, we haven't left it like that for more than a minuet or so. We do have fans in the floor under the fridge, we don't run the fans in winter, but of course there's a gaping hole in the floor below the fridge motor, so cool air is naturally drawn through these holes, also assists good ventilation in the boat.

 

We have a very accurate clamp ammeter too, but isolating the single 240 live wire to the fridge is tricky.

 

Yep, a single amp reading on a fridge won't work, there only really on 50% of the time! You could get a plug in monitor for around £10 from Argos that will tell.

Edited December 31, 2013 by Robbo

[Ex- Member]

My view....

 

The main plus point with gas is that although quite inefficient is that it uses what it uses there and then.

 

The down side with electric fridges (either 12v or 240v) is producing your own electric. To make it efficient you have to have the right size generator for your charger and then batteries. If any of these are way off then it's going to inefficient.

 

Fair point, but now with the advent of solar those downsides are greatly lessened if fitting it in a reasonable quantity. We're finding 740w is sufficient for at least 8 months of the year, the remaining for months requiring minimal charging from other sources such as boat engine and wee generator.