Carbon Monoxide Detectors

[Chaps]

Santa bought us a Carbon Monoxide detector for our caravan this year after our local newspaper reported the sad deaths of two gentlemen who were enjoying a drink together in a caravan with the heating on and were overcome by fumes. Better to be safe than sorry.

On that cheerful note - Happy New Year everyone!

 

[GrahamSouthBrum]

If my understanding of the situation is correct I am sure that you shouldnt need one.

I am sure that all gas fires fitted in caravans have to have the combustion chamber fitted externaly, making the occupants of the caravan safe from combustable gas fumes.

I await with baited breath to be shot down, but as you have the alarm better safe than sorry.

G.

 

[Damian]

Having read the above post I am quite intrigued to know what kind of caravan the gentlemen were in when this unfortunate thing happened.

With all modern touring caravans all appliances except the cooker are room sealed, which is why I am curious.

On the other hand, static vans do have open flued fires, much the same as home type fires.

In either case, I would have thought the emphasis should be on the real need for regular servicing and if that costs money to ensure your safety, then so be it, how much is your life worth?

 

[ProfJohnL]

Hello Clair & Rob,

Firstly as both Graham and Damian have pointed out modern (post 1985) can only be fitted with a 'room sealed' heater. Provided they are properly installed and maintained then the risk of Carbon Monoxide gas entering the living space from the heater is absolutely minimal. Whilst a CO detector will give you some peace of mind it is not strictly necessary.

Graham's description of an 'external' heat exchanger is perhaps a little misleading: Its not out side, but inside,

All Attwood, Carver, Electrolux, and Electrolux heaters are room sealed. This means that actual flame is contained in a tube which is only open underneath the caravan to draw in air for combustion and through the roof for the chimney. A heat exchanger is usually sited on the floor of the caravan, and this forms part of the tube. - so no products of combustion are allowed to escape the tube into the caravan.

As a result you only get the air inside the caravan being heated from the exchanger, and all products of combustion are exited up the tube and through the roof.

There is an exception to this. The Carver & Truma SB1800 models still have room sealed operation, but due to the very high efficiency of the heat exchanger the exhaust gasses are so cool they are driven back down through the floor and dissipate underneath the caravan.

Proper regular servicing of all gas appliances is important. In a caravan where for much of the time the caravan is not used, it is not uncommon for insects to get inside the burner assemblies. When they do, they often disturb the system that mixes the gas air before burning (Venturi Tube) When this happens, the actual flames will often appear languid and have the appearance of a candle flame. This is a sure signal to have the appliance serviced.

I must point out that to undertake to install, service, repair or remove any gas appliance you must be competent to do so. So unless you are trained and are fully conversant with the gas regulations, you must find a competent person to do it.

 

[Chaps]

Thanks, gents - you've all really put our minds at rest. We seem to remember that the caravan in question was quite dated but we just decided better safe than sorry especially as we holiday with 3 kids. We have a new caravan so with all the technology that you've described we're pretty sure it's unecessary to have a CO detector but we'll use it just in case.

Cheers!

 

[Garfield]

I remember Mum & Dad having a freestanding gas fire in their old caravan. Short of the heat exchanger or the flue pipe being badly holed it is not feasible for a modern caravan heater to pass fumes into the caravan.

 

[ColinA]

claire and rob, gas cookers can and do produce CO so so its not a waste of time

Colin

 

[Guest]

I agree with Colin, gas cookers etc etc etc. Then there's the gas fridge. And room-sealed heaters have been known to leak.

Since you got it for a Christmas Present, why not use it?

We have one and would rather use one than not.

 

[ProfJohnL]

Hi Clare and Rob

I fell I must add further comment in response to Garfiled, Colin A and Legsmaniac's latest posts. These are not designed to alarm you but to put them into context and add some detail to their posts

Garfield is correct when he implies the danger is minimal unless badly holed. As with a domestic open fire, the chimney tries to 'draw' the fire. The hot fumes being very much lighter than air cause this and by trying to rise, they create a negative pressure in the flue pipe. So if the flue is punctured, (hook of a coat hanger or a pencil etc) then it will tend to suck air in rather than expel fumes. If the hole is significant, or the flue pipe is disconnected from the chimney, then the flue gasses will start to enter the caravan. The likely hood of this type of problem is relatively small, the flue pipe is made of flexible duct that tends to deform rather than puncture. It is also enclosed in an outer sheath or boxed in.

The condition of the flue is one of the standard inspections during the service of a gas appliance.

Gas cookers and ovens are generally open flamed, meaning they do not have a dedicated flue to the outside. So they will deposit any CO they produce into the living area of the caravan. This is allowed because as part of the caravans design and type approval, it has to have a specified amount of 'fixed ventilation' shared between high and low level vents. These must never be blocked. The other reason is that a cooker/oven is only used for a relatively short time unlike a heater, which may be on for 24H. In my view, it should be part of any caravan service to check that the vents are working.

Legsmaniac introduces the fridge to the equation. Here the normal fixed caravan fridge has its own air intake and exhaust ports on the outside wall of the caravan. You may note that this is often on the side where the awning goes. This is allowed because the size of flame is very small (typically 100 to 200W) and the volume of fumes will easily dissipate through the normal ventilation in a awning. Because of the design and installation none of these fumes should enter the caravan but even if they did the normal ventilation will be more than enough to offset an increased CO.

I should also add that all the current water heaters for touring caravan have to be room sealed, so the same level of safety is created there.

I can only stress that the risk of dangerous levels of CO occurring in a properly maintained caravan are very very low. There is absolutely nothing wrong in fitting a CO monitor, but do make sure you check its battery regularly as with the smoke detector.

Happy caravanning.

 

[Hazel_374324904]

For those of you that wish to be better safe than sorry, B&Q are selling battery run carbon monoxide monitors for