Running caravan fridge on Solar panels

[johnandrew70]

Does anyone know how many watts a caravan fridge consumes, the reason i ask is a friend of mine has asked if my setup of solar panels would run the fridge as he is thinking of fitting solar panels as i have.
my setup is 2x 80watts and a 110ah battery.
Would it work if there were 2 110ah batteries and ran the fridge from an inverter ??

I am sure someone would know if it can be done?

 

[WoodlandsCamper]

I believe a fridge needs a higher wattage at 12v than solar cells can produce (unless the whole caravan roof is covered in them).

 

[Dustydog]

An average dometic fridge at 12 volts draws 120 watts orr. 2.2 kwh per 24 hour period..

 

[johnandrew70]

An average dometic fridge at 12 volts draws 120 watts orr. 2.2 kwh per 24 hour period..

with these figures the battery would be dead in a short period of time. how many watts on 240v does anyone know, maybe an inverter would be better with 2 batteries

 

[WoodlandsCamper]

If a fridge doesn't run on 12v then converting 12v into 230v via an inverter (which has losses) is going to be even worse. You don't get something for nothing!
That's why caravan fridges also work from a gas supply when there's no electrical hook-up.

 

[johnandrew70]

If a fridge doesn't run on 12v then converting 12v into 230v via an inverter (which has losses) is going to be even worse. You don't get something for nothing!
That's why caravan fridges also work from a gas supply when there's no electrical hook-up.

I am not sure why he is not using gas to be honest, i will ask him when i see him.

Thanks for your input.

 

[Dustydog]

John
230 volts runs at 125 watts.
Same kwh per 12 v give or take a bit.
I don' the know much about solar panels other than they don't work at night!

 

[johnandrew70]

John
230 volts runs at 125 watts.
Same kwh per 12 v give or take a bit.
I don' the know much about solar panels other than they don't work at night!

Yea i found that they dont work at night, i even shon a torch on it hahaha

Apparently my mate wont use the gas side of the fridge (Electrolux RM121) becuse his other half doesn't like the idea of having the gas on at night, and there kids sleep in the awning the same side as the fridge vent.

Any ideas ??

 

[WoodlandsCamper]

Don't take the kids. :evil:

 

[johnandrew70]

hahaha nice one even better dont take the kids or the wife

 

[ProfJohnL]

John
230 volts runs at 125 watts.
Same kwh per 12 v give or take a bit.
I don' the know much about solar panels other than they don't work at night!

Yea i found that they dont work at night, i even shon a torch on it hahaha

Apparently my mate wont use the gas side of the fridge (Electrolux RM121) becuse his other half doesn't like the idea of having the gas on at night, i thought they had a valve that shut off the gas if the flame went out??

Any ideas ??

We have heard this concern several times before.

You should always treat gas appliances with due caution by ensuring they are properly maintained and used properly, But having done that, ALL caravan fridges are designed to work safely on gas 24/7.

By design the fridge (along with the gas water and space heaters) have a Flame Failure device, which will turn the appliance gas off if the flame goes out. On top of that these appliances are 'room sealed' which means they segregate all the combustion and fumes from the living area. Both these processes means these gas appliances are actually very safe.

Even if a fault occurred and the room seal was breached, the fridge produces a relatively small amount of fumes, which should be diluted and dispersed by the caravan standard fixed ventilation. You get far more fumes from the gas cooker or oven which do vent into the living area!

If your fridge does have a problem, then its going to be a problem during the day not just at night. So if you have any doubts get the fridge checked or serviced.

 

[Gafferbill]

Apparently my mate wont use the gas side of the fridge (Electrolux RM121) becuse his other half doesn't like the idea of having the gas on at night, and there kids sleep in the awning the same side as the fridge vent.

A very sensible lady.

...........this is a real danger and is a problem when sleeping in some awnings that cover gas appliance exaust vents.

I would personally stick to sites with an electric hook up if my children slept in such an awning.

 

[ProfJohnL]

Hello Gaffer,

There is nothing wrong with not wanting to use a fridge on gas, but it the reason is due to an incorrect understanding of the issue then it may be time to re-evaluate matter.

You will not from my earlier reply about fridge fumes. The quantity produced is very small compared to other gas appliances. Where fridges vent into awnings, I've yet to see an awning that is so air tight as to be realistic issue with a fridge.

Yes there have been some sad incidents of caravanners suffering CO poisoning from using a solid fueled BBQ inside an awning. CO (Carbon Monoxide) is the result of poor quality combustion, and BBQ's by smoldering produce a very large proportion of CO. By comparison a properly maintained fridge burner flame, its quality of combustion is very good producing very small percentages of CO.

There is also a big difference between the sheer volume of products of combustion broduced between the typical BBQ and the typical fridge. Most fridges use about 100 to 150W of gas, where as even a relatively small BBQ is likely to be consuming 2 to 3kW of fuel. Its quite likely the a BBQ will produce between 1000 to 2000 times or more CO than a well adjusted fridge.

To be fair we tend to use sites with EHU, but for myself I have no qualms about using a gas fridge venting into an awning, and that's with my background and understanding of gas engineering.

 

[Willi-Wonti]

We were turned out to a flat fire a couple of years ago. On arrival smoke was seen to be coming out of a 1st floor window.
We were told to start up our BA sets & take a hose reel to the 1st floor.
Entry was gained by kicking in the door & on entry to the living room were confronted by a family using a BBQ hmy:
We used our hose reel on the BBQ & removed it onto the balcony
The family were then warned about the dangers of CO. I don't think they had a brain cell between them

 

[Dustydog]

Hi John
400ppm of CO will render unconsciousness. Anything above that and you are dead within two hours or less.
As I know from personal experience a fully serviced gas item is no guarantee something won't go wrong before the next service.
CO exhausting 9nto an awning with sleeping children does not sound good practice to me. A failed fridge burner may produce more CO than we think.
Sorry. Call me a coward but no way would I allow my grand children to sleep in an awning with a gas fridge exhausting into the area.

 

[johnandrew70]

Hi guys
Didn't think this thread was going to start things off like they have but glad i have brought something up that seems to be a problem with fridge vents on the awning side of the caravan.
My mate said his fridge has been serviced regularly but to be honest something can go wrong anytime with the fridge burner as Dustydog has said.

My advise to my mate is to buy a porch awning and put it on the other side of the van for the kids to sleep in. :evil:

 

[ProfJohnL]

Hi John
400ppm of CO will render unconsciousness. Anything above that and you are dead within two hours or less.
As I know from personal experience a fully serviced gas item is no guarantee something won't go wrong before the next service.
CO exhausting 9nto an awning with sleeping children does not sound good practice to me. A failed fridge burner may produce more CO than we think.
Sorry. Call me a coward but no way would I allow my grand children to sleep in an awning with a gas fridge exhausting into the area.

Hello Dusty

As I said its a matter of personal choice after understanding and balancing up the risks. I confess I hadn't noted the fact it was children involved, and so I fully understand the posters concerns.

As always if in doubt always err on the side of safety.

 

[colin-yorkshire]

hi all.
I'm with the Prof on this one, sounds like a lot of hot air to me
of course I cannot speak for everyones awning but the ones I have use are about as air tight as a colander is water tight, quite draughty in fact, especially in the vented window dept.
if there was any risk from the gas vents from the fridge does anyone seriously believe manufacturers would still be fitting fridges vented on the awning side, a practice as old as vans themselves.
our first van built in 1967 had a electrolux 122 (gas only) fridge that vented on the door side some 47years ago, OH and by the way had a open fronted gas fire and gas mantles for lights. yet in all the years since then no mention has been made of any risk. using a awning on a van.

My advise to my mate is to buy a porch awning and put it on the other side of the van for the kids to sleep in. :evil:

yeah good idea John then they can breath in the exhaust from the water heater instead. :woohoo: that is on the other side of the van.

 

[Gafferbill]

yeah good idea John then they can breath in the exhaust from the water heater instead. :woohoo: that is on the other side of the van.

I am sure John specifically mentioned a porch awning because it could be fitted without covering any gas appliance exhausts thus allowing it to be safely slept in.

..........and guess what Colin!

........ on my Swift there is a warning notice in the form of a window sticker placed on the front offside side window.
This window opening is 60 cms above the water heater exhaust vent which is on the outside of the caravan.

I quote the warning sticker placed on the window by Swift.

WARNING. We advise not to open this window when the water heater is used on gas operation.

You could argue that no way would harmful gases make it through the window in sufficient quantities to cause a problem especially as the window would be open giving extra ventilation.
Swift do not argue that instead they issue a warning to keep it closed......implying they the manufacturer thinks there is a risk.

At any given time no one knows if a gas appliance is operating correctly (unless it is tested by an expert there and then) and no one can be certain an awning is sufficiently well ventilated to allow it to be used for sleeping in all possible scenarios.

Some modern caravans now have floor to ceiling refrigerators with quite a large freezer compartment and their gas burner has considerately more output than caravan refrigerators used to have.

 

[johnandrew70]

What i would like to know is why don't caravan manufacturers vent the fridge flue the same way as they do for the space heater, Surely this would be easy enough to do by boxing in a flue pipe right up to the ceiling,
I understand the ordinary fridge vents need to be there so that cool air circulates and cools the fins on the back but i could never understand why the flue had to be there as well. I am sure there is a reasonable explanation for this.

 

[Damian]

What i would like to know is why don't caravan manufacturers vent the fridge flue the same way as they do for the space heater, Surely this would be easy enough to do by boxing in a flue pipe right up to the ceiling,
I understand the ordinary fridge vents need to be there so that cool air circulates and cools the fins on the back but i could never understand why the flue had to be there as well. I am sure there is a reasonable explanation for this.

Simple answer,Cost!

 

[DeliDave_]

To be fair a porch awning on the offside could be a good solution as you dont need the water heater on all night,a CO detector in the awning would be an option.I personally would find a site with electric or turn the fridge off before I went to bed Fridges are fine on the overnight ferry turned off and my grandkids are up at first light so nothing would thaw out too much

 

[ProfJohnL]

What i would like to know is why don't caravan manufacturers vent the fridge flue the same way as they do for the space heater, Surely this would be easy enough to do by boxing in a flue pipe right up to the ceiling,
I understand the ordinary fridge vents need to be there so that cool air circulates and cools the fins on the back but i could never understand why the flue had to be there as well. I am sure there is a reasonable explanation for this.

Hello John,

Damian has given you the finance directors answer, but the technical director would have two linked technical reasons:

The problem with small flames is they don't release a lot of heat and that means they are far more sensitive to external influences such as flue terminal temperature and length.

In a convection combustion tract you need enough heat in the products of combustion to keep them buoyant and thus intent on rising. If you increase the length of a flue, the increased surface area of the flue can cool the flue gasses more, and with the small flame of a fridge, it could easily cool enough to condense and baffle back.

You would have to increase the size of the flame just to drive the flue, and that will adversely affect the thermal efficiency, which by law must be more than 70%.

Interestingly, the original Truma/Carver 1800 series heaters managed to use the efficiency of the heat exchanger to cool the flue products enough to allow them to be ejected below the floor, they also condensed and could give gross efficiency of over 90%.

The same could not be done for the 3000/3600/5000 heaters as the flue products were too hot after they left the cast heat exchanger so they needed a continually rising flue to 'draw' the air and flue gasses through the heater.

Condensing domestic boilers achieve their improved efficiency by passing the flue products over additional heat exchangers, To do this and to overcome variable length flues they utilise forced air or blown combustion to drive the flue products.

 

[stevesnrs]

Hi John,
the solar panels don't run the fridge they charge the batteries, so if you have your fridge set to run on 12v, it would take its power from the batteries being charged by the panels, so no need for an inverter which is less efficient.
An 80w panel produces in the region of 4-5 amps max, so your two panels would produce 8-10 amps max
A fridge consuming 120watts at 12 volts is 10 amps, therefore the panels would struggle during the day and at night the battery would be flattened, so the short answer is no, unless you fit extra panels to produce more power than is being consumed, and more batteries to store more power over night so they are not flattened.
Hope this helps
Steve

 

[Dustydog]

Steve
Are you sure your statement is correct?
My last four caravans did not draw power from the leisure battery for the fridge.. The fridges only worked on 12v when connected to the towing vehicle and then only when the engine was running.????????