Gas Fridge

[Liam]

After a good few years of my parents going without a fridge whilst cruising, and only being able to run the fridge on 240v whilst on the moorings landline, they've finally removed the fridge and have taken it to get overhauled. It's since come back and works like new so no problems there.

 

My parents asked "Bob" to come and install the Gas fridge for them, being fully qualified in all things gas. Eventually he had some free time and so came down to the moorings tonight and spent time fixing the area around the frige with heat proof boarding (which is all neatly done) and connected the fridge up to the old gas line and tested it for leaks. There were none so all is fine and dandy..

 

Apart from the fact that I noticed "Bob" was fitting the fridge with no pipe from the fridge exhaust to the existing fridge vent on the gunnel line. There used to be one fixed onto the fridge but this was too short and had been rubbing something at some point and was a bit thin with a hole appearing in one place. I asked him about this and he said that no, it'd be fine without one and there was enough ventilation around the fridge for it to be OK. Now call me daft but the fridge being well ventilated is one thing but the fridge being able to exhaust the fumes outside the boat is another thing entirely.

 

I'm just wondering what others thought... which leads me to my next question...

 

Where am I able to buy a new length of exhaust pipe for the fridge?

 

Ta

[Stormbringer]

Hi Liam

 

I am new to narrowboats, but in my working life I am a caravan engineer.

I know in the caravans I service that there are (generally) two types of 3 way fridge used..Dometic and Thetford (who frankly should have stuck to making toilets !!)

The Dometic ones have an exhaust which vents outside of the caravan and the Thetford ones vent into the back of the enclosure behind the fridge !

HOWEVER - the fridge itself MUST be sealed from the living area of the caravan by closed cell foam and/or suitable tape...

AND caravans have two sodding great big vents [from outside] into the space behind the fridge....

I am not sure what the regs are with boats but I personally would NOT be happy with a set up like you mention.

I'm not sure what make your fridge is but I would check with the manufacturers if possible for advice.

Some don't even allow exhaust extensions to be used at all....

 

As a foot note - the surveyor who recently surveyed my boat (pre-purchase) was very happy to see the fridge NOT connected to gas and recommended that I leave it that way too.

 

Sorry I can't help more

Cheers

Andy

 

Edited to add [from outside]

Edited July 14, 2011 by Stormbringer

[Guest]

Liam,

 

I'm drawing on my caravanning experience too and I can't see how it can be safe at all for a gas fridge to vent it's combustion gases to the inside of the boat. The amounts may be small but given it runs virtually 24/7 unlike an instantaneous water heater I wouldn't be happy.

[alan_fincher]

When gas fridges were the norm some years ago, before the general arrival of 12 volt electric compressor fridges, I believe that the norm was that they just vented into the cabin area, and generally had no external flue.

 

Although that may sound surprising, vast numbers of both hire and private boats were built this way, and I don't recall frequent cases of people dying from carbon monoxide poisoning as a result.

 

So far as I'm aware the current BSS regs still no longer demand an external flue, (I know this may surprise some!), although the BSS office themselves "strongly reccomend" fitting electric fridges rather than gas, (the actual regs do not enforce this, though....).

 

Personally my preference is an external flue, but, in the typical narrow boat case, if you have a small Electrolux fridge set at floor level, it is unlikely the normal flue kit will reach to a suitable place for putting a vent through a cabin side. That means you often see them through hull sides, and that there is a good chance they will get damaged if not well guarded. (Ours has a large 6mm steel vent with drilled holes, protecting it, but the latter does have the occasional fight with passing lock-sides and coping stones.)

 

If you can arrange to mount the typical Electrolux fridge higher, it would probably be easier to use the proper venting kit unmodified, and have the vent on the cabin side (where it isn't a problem) rather than on the hull-side (where it can be....).

 

You are NOT supposed to modify of lengthen in any way the standard Electrolux add on external flue, and I'd advise against doing so......

[Guest]

It is strange that the regs are so different for caravans and boats.

 

They are theoretically the same in that they are metal boxes, the only thing I can think of that makes them different is the overall internal size which I would guess is generally greater in a boat.... thereby given more opportunity for the combustion gases to dissipate..

 

but then that doesn't hold true for some boats with small rear located cabins which will be much smaller than your average caravan.

 

Curious to say the least.

[alan_fincher]

It is strange that the regs are so different for caravans and boats.

Actually I don't think boats and caravans are at all similar.

 

With a caravan, it is (as I understand it) possible to arrange that a fridge, (although not of what is strictly called a "room sealed" or "balanced flue" type), can still effectively have its combustion parts isolated from the caravan inside. You can have as many vents as you need, at whatever level, to ensure that fresh air gets drawn in from outside, not from the cabin, and that exhaust gas goes outside not inside.

 

You can't do this with a boat, unless it is possible to mount the fridge completely above gunwale height, and arrange to have vents both to supply fresh air, and expel exhaust gasses, whilst in some way sealing the fridge into it's surround to isolate it's combustion areas from the boats inhabitants. I'd imagine that's hard to achieve, (having never seen it done!), and the reality is that most LPG fridges used on boats are truly "non room sealed", and draw their air from the cabin. Unless arrangements are made to flue overboard, exhaust gasses will end up inside.

 

Even the proper Electrolux flues, properly installed, are not room sealed, and at best will get most, but not all the combusted material outside.

 

Also if you get a gas leak on a caravan fridge, the gas will probably dumped outside - on a boat it will be dumped into the bilges - clearly a far greater danger, particulay as the fridge presents a naked flame in the same area!

 

So actually the rules for installing on boats should really be more restrictive than in caravans, not less so!

 

That said, despite all the hysteria there now is about gas fridges and Morco / Paloma type water heaters in boats, as I said they were for many years the norm, and if people treat them correctly, keep them in good repair, and keep a cabin properly ventilated, there is no huge track record of them killing people, (or at least the BSS office have never been able to provide data that proves there is a great inherent danger).

 

All that said, and generally being a fan of gas fridges in narrow boats, I'm not sure these days I'd want to have one with no external flue - even though (unless anyone can prove otherwise!) the BSS actually fully allows it.

[mrsmelly]

When gas fridges were the norm some years ago, before the general arrival of 12 volt electric compressor fridges, I believe that the norm was that they just vented into the cabin area, and generally had no external flue.

 

Although that may sound surprising, vast numbers of both hire and private boats were built this way, and I don't recall frequent cases of people dying from carbon monoxide poisoning as a result.

 

So far as I'm aware the current BSS regs still no longer demand an external flue, (I know this may surprise some!), although the BSS office themselves "strongly reccomend" fitting electric fridges rather than gas, (the actual regs do not enforce this, though....).

 

Personally my preference is an external flue, but, in the typical narrow boat case, if you have a small Electrolux fridge set at floor level, it is unlikely the normal flue kit will reach to a suitable place for putting a vent through a cabin side. That means you often see them through hull sides, and that there is a good chance they will get damaged if not well guarded. (Ours has a large 6mm steel vent with drilled holes, protecting it, but the latter does have the occasional fight with passing lock-sides and coping stones.)

 

If you can arrange to mount the typical Electrolux fridge higher, it would probably be easier to use the proper venting kit unmodified, and have the vent on the cabin side (where it isn't a problem) rather than on the hull-side (where it can be....).

 

You are NOT supposed to modify of lengthen in any way the standard Electrolux add on external flue, and I'd advise against doing so......

 

I agree with this. The two oldest boats I have owned both had the electrolux gas fridges. Neither had any form of venting except directly into the boat. As said by others it doesnt seem a sensible idea but it was standard to do that and we all survived and one of my old boats still has same fridge and system fitted. Those old gas fridges were great and changing a gas bottle every couple of weeks is better than having to charge batteries on a very regular basis

[ridders]

After a good few years of my parents going without a fridge whilst cruising, and only being able to run the fridge on 240v whilst on the moorings landline, they've finally removed the fridge and have taken it to get overhauled. It's since come back and works like new so no problems there.

 

My parents asked "Bob" to come and install the Gas fridge for them, being fully qualified in all things gas. Eventually he had some free time and so came down to the moorings tonight and spent time fixing the area around the frige with heat proof boarding (which is all neatly done) and connected the fridge up to the old gas line and tested it for leaks. There were none so all is fine and dandy..

 

Apart from the fact that I noticed "Bob" was fitting the fridge with no pipe from the fridge exhaust to the existing fridge vent on the gunnel line. There used to be one fixed onto the fridge but this was too short and had been rubbing something at some point and was a bit thin with a hole appearing in one place. I asked him about this and he said that no, it'd be fine without one and there was enough ventilation around the fridge for it to be OK. Now call me daft but the fridge being well ventilated is one thing but the fridge being able to exhaust the fumes outside the boat is another thing entirely.

 

I'm just wondering what others thought... which leads me to my next question...

 

Where am I able to buy a new length of exhaust pipe for the fridge?

 

Ta

most caravan dealers can order a replacement flue kit, they just need to be cut to length, i think the electrolux ones are about £30 ish

also you can duct a low level vent to the bottom below the fridge

hope this helps

paul

Edited July 21, 2011 by ridders

[sueb]

Our gas fridges have always vented straight into the boat and we are still alive (I think) 20+ years living aboard and using the boat for pleasure.

Sue

[NBMike]

most caravan dealers can order a replacement flue kit, they just need to be cut to length, i think the electrolux ones are about £30 ish

also you can duct a low level vent to the bottom below the fridge

hope this helps

paul

I just bought the flue kit yesterday. They're £52 now!

[ridders]

Our gas fridges have always vented straight into the boat and we are still alive (I think) 20+ years living aboard and using the boat for pleasure.

Sue

maybe you should read your own signature sue

some people have smoked heavily for 50 years and survived,doesn't mean it's clever though!

[twbm]

Out of interest, question to all those who insist gas flames should be vented overboard. How do you cook a meal?

[Nb Unity]

Well , weve had the fridge installed by a gas fitter friend to run off gas, we tried it in the week for a couple of hours with a carbon monoxide detector positioned very near the fridge , and all seems well , said gas fitter said hel " vent it " when we get back off our two week trip out if we require it ,wel see how it goes when we cruise next friday

[ridders]

best answer i can give would be all gas appliances should be fitted in accordance with the manufacturers instructions, any required flues should be fitted to the instructions and tested, and adequate ventilation must be supplied.supply pipework to any appliance must be correctly sized so as not to give lower gas pressure than required to burn correctly. appliances must be installed and commissioned by those competent to do so, and maintained regularly

the main point for me with a gas fridge is that you don't want fumes recirculating through the burner, as that will produce carbon monoxide, which is why the manufacturer supplies a flue. If they don't need one the instructions for that model will say so.

sorry if this sounds arsy, but its not something to mess with (and installations contravening the instructions would invalidate your insurance when something does happen)

paul

[sueb]

maybe you should read your own signature sue

some people have smoked heavily for 50 years and survived,doesn't mean it's clever though!

It may not be clever to have a fridge venting into a boat but it is legal and causes no problems. My drinking a glass of wine a week probably does me more harm.

Sue

[twbm]

Out of interest, question to all those who insist gas flames should be vented overboard. How do you cook a meal?

 

No takers so far. Our gas cooker has 4 rings, each of which from memory has about 24 jets each roughly the same size of the flame on a gas fridge. Running three of them for twenty minutes puts 24 x 20 x 3 = 1440 'jet minutes' of fumes in to the cabin, i.e the same as a fridge produces in 24 hrs.

 

I nearly lost my wife to CO poisoning many years ago so I'm not dismissing the issue, but if gas rings are OK, why not a fridge flame?

[ridders]

No takers so far. Our gas cooker has 4 rings, each of which from memory has about 24 jets each roughly the same size of the flame on a gas fridge. Running three of them for twenty minutes puts 24 x 20 x 3 = 1440 'jet minutes' of fumes in to the cabin, i.e the same as a fridge produces in 24 hrs.

 

I nearly lost my wife to CO poisoning many years ago so I'm not dismissing the issue, but if gas rings are OK, why not a fridge flame?

it's generally accepted that you would open a vent whilst cooking and probably be observant, where the fridge or water heater is on 24/7 with only the fixed ventilation to feed them, i do understand your question but the appliance manufacturers have already designed and tested their appliances which is why some need a flue. a room sealed cooker would be better as well but hardly practical - but here's my question what possible benefit could be gained from running a flued appliance without a flue-it's just stupidity

[twbm]

Your last point makes complete sense, so I guess it's about picking an appropriate fridge, I fitted one of these:

 

http://www.ebay.co.uk/itm/NEW-UPRIGHT-CARAVAN-CAMPING-3-WAY-GAS-12V-240V-FRIDGE-/230643323612?pt=UK_Campervan_Caravan_Accessories&hash=item35b369d2dc#

 

which has no requirement for an external flue. So far it's proving to be very efficient.

 

Edited to add: Everything else you said makes sense too!

Edited July 24, 2011 by twbm

[sueb]

it's generally accepted that you would open a vent whilst cooking and probably be observant, where the fridge or water heater is on 24/7 with only the fixed ventilation to feed them, i do understand your question but the appliance manufacturers have already designed and tested their appliances which is why some need a flue. a room sealed cooker would be better as well but hardly practical - but here's my question what possible benefit could be gained from running a flued appliance without a flue-it's just stupidity

We don't open a window whilst cooking in the winter but we do have a carbon monoxide tester. I don't take monoxide poisoning lightly

Sue

[alan_fincher]

best answer i can give would be all gas appliances should be fitted in accordance with the manufacturers instructions, any required flues should be fitted to the instructions and tested, and adequate ventilation must be supplied.supply pipework to any appliance must be correctly sized so as not to give lower gas pressure than required to burn correctly. appliances must be installed and commissioned by those competent to do so, and maintained regularly

the main point for me with a gas fridge is that you don't want fumes recirculating through the burner, as that will produce carbon monoxide, which is why the manufacturer supplies a flue. If they don't need one the instructions for that model will say so.

sorry if this sounds arsy, but its not something to mess with (and installations contravening the instructions would invalidate your insurance when something does happen)

paul

I don't know about these days, but it certainly used to be the case that as supplied Electrolux fridges did not come with an external flue kit included.

 

That was an optional extra, so I would argue there must have been applications where it was considered the flue was not needed. However as they never said these Fridges were suitable to fit in boats, the point becvomes a bit academic!

 

Certainly in the 1970's our LPG Electrolux fridge vented direct into the cabin, and it never occurred to me it should not.

 

I believe most hire boats were the same.

 

I'd not do it now, though, (personally).

[MtB]

Out of interest, question to all those who insist gas flames should be vented overboard. How do you cook a meal?

 

 

With a cooker, which is a 'flueless appliance'.

 

Flueless appliances are designed for operation under the continuous supervision of a user. A flue is fitted to appliances designed for unsupervised operation.

 

The risk is associated with products of combustion entering the living space. It's a subtle risk for the layman to grasp but I'll have a bash at explaining it since you ask.

 

Contrary to popular opinion, the products of combustion from a correctly operating gas appliance are perfectly safe to breathe. The products of full combustion of gas are water vapour and carbon dioxide, both benign to human beans. (There are a few other small constituents but they are of no consequence from a safety point of view.)

 

So, a correctly burning appliance presents no risk to humans even if the flue is blocked or missing. The problem arises once the appliance has been burning for a while because combustion uses oxygen. The oxygen comes form the air around the flame. If a flue (or the fresh air supply) is blocked then there is no flow of combustion products out of the room, and therefore no flow of fresh air INTO the room bringing in new oxygen with it.

 

Once the oxygen concentration in the combustion air falls below the 20% the burners are designed to operation with, incomplete combustion begins to occur. Incomplete combustion results in production of carbon MONOXIDE as well as carbon dioxide and water vapour. The combustion products are now potentially dangerous to humans and animals and these products of combustion are spilling out into the room instead of going up the flue because it (or the fresh air supply) is blocked.

 

As the oxygen concentration in the air falls, the proportion of CO production rises. The longer the burners run without a supply of fresh air, the higher the concentration of CO in the room and the more danger is presented to any occupants. CO kills people because their blood picks up the CO from their lungs in preference to oxygen and carries it around the body instead, and eventually the brain is starved of oxygen and dies. Not a process you will be conscious of happening.

 

The cooker you use for your meal is every bit as capable of killing you if you operate it in a enclosed space with all doors and windows closed. The thing is, users instinctively open a door or window if the kitchen gets a bit hot, thereby allowing fresh air ans oxygen in to prevent the runaway effect I described.

 

A clumsy explanation perhaps, but I hope that helps you understand.

 

Mike

[ridders]

[

A clumsy explanation perhaps, but I hope that helps you understand.

 

Mike

nope-very eloquently put mike

[smileypete]

Once the oxygen concentration in the combustion air falls below the 20% the burners are designed to operation with, incomplete combustion begins to occur. Incomplete combustion results in production of carbon MONOXIDE as well as carbon dioxide and water vapour. The combustion products are now potentially dangerous to humans and animals and these products of combustion are spilling out into the room instead of going up the flue because it (or the fresh air supply) is blocked.

Isn't it yellow flames or partly yellow flames that produce CO?

 

In other words a completely blue flame cannot produce CO?

 

From www.hse.gov.uk Gas safety - Carbon monoxide awareness

 

ETA: In answer to the OP's original question, an externally flued non room sealed fridge should have a 'draft diverter'

 

That said, whether internal or external flued fridge, a CO alarm must be fitted.

 

cheers,

Pete.

Edited July 25, 2011 by smileypete

[MtB]

Isn't it yellow flames or partly yellow flames that produce CO?

 

In other words a completely blue flame cannot produce CO?

 

 

 

I think this is a good example of how 'misinformation' spreads. Could you point out where it says blue flames can't produce CO in the link you gave please, because I can't spot it! How many people failed to notice the question mark on the end of your underlined statement? I wonder.

 

Getting back to the subject, a flame with any part yellow definitely IS producing CO. The quantities may still be small but the cumulative effect can still be dangerous. As I understand it, the absence of 'yellowness' in combustion is certainly no guarantee of the absence of CO in the products of combustion however.

 

'Flame chilling' for example causes CO generation. Perversely, cookers are a good example. A blue cooker ring flame chilled by playing on the underneath of a saucepan will be producing CO, or so we are told in training. I've not tested this personally yet with my gas analyser. I will try it later!

 

 

That said, whether internal or external flued fridge, a CO alarm must be fitted.

 

cheers,

Pete.

 

 

Since when? Do you have a source for this requirement please because I have not heard about this? It's good advice but not complusory as I understand it.

 

Thanks.

Edited July 25, 2011 by Mike the Boilerman

[pmms]

I think this is a good example of how 'misinformation' spreads. Could you point out where it says blue flames can't produce CO in the link you gave please, because I can't spot it! How many people failed to notice the question mark on the end of your underlined statement? I wonder.

 

Getting back to the subject, a flame with any part yellow definitely IS producing CO. The quantities may still be small but the cumulative effect can still be dangerous. As I understand it, the absence of 'yellowness' in combustion is certainly no guarantee of the absence of CO in the products of combustion however.

 

'Flame chilling' for example causes CO generation. Perversely, cookers are a good example. A blue cooker ring flame chilled by playing on the underneath of a saucepan will be producing CO, or so we are told in training. I've not tested this personally yet with my gas analyser. I will try it later!

 

 

 

 

Since when? Do you have a source for this requirement please because I have not heard about this? It's good advice but not complusory as I understand it.

 

Thanks.

Mike, always good to have some sense injected into the topic.

 

FYI I understand that a co detector/alarm for marine use is close to availability, along with fitting/location instructions.

 

On the subject of flueing lpg fridges into the accommodation spaces, although the majority of the unflued fridges have a low heat input rating, (0.2kw?) and thus attract a small increase in fixed ventilation, as you know many of these fridges suffer with a poor flame picture due to insects, corrosion in the pipework of the flue pipe. I remember electrolux saying that fridge flues should not be extended beyond the length supplied in their kit as condensation can occur in the pipe and cause the extended pipe to deteriorate. Of course the room sealed fridge is no longer available so will we see a campaign to allow the non room sealed version to be fitted, as occurred with instantaneous water heaters.

 

Paul M