Cooling fridge - which is cheaper Electric or LPG

[VXman]

So, I need to cool the fridge on my drive prior to a trip.

LPG @99p per litre Fridge consumption 468g in 24 hours
Mains electric @ £0.225 per kwh power consumption - 240W

I could probably work it out but I'm not totally confident in my maths and electric understanding.

Appreciate some other input.

 

[VXman]

If it helps OP on our fridge in summer, I clocked the fridge at using 3kwh over 24 hours to cool. That was at 24 celcius outside average. I suspect it'd use rather more (around 1 kwh every 3 hours) if it was warmer as that was the peak usage.

thats 66p

 

[VXman]

You need a compressor fridge next time you buy one then. Mine runs on sunshine power, it's a bit cloudy today here but there's still enough solar to run the fridge AND recharge the battery

This one is only 2 years old. They cost nearly £1500, I hope never to change it - will probably sell the van first.

 

[starquake]

thats 66p

Yes, but it'd probably be more than the gas at 30 celcius with the peak usage I metered (250-300w constant), so likely quite a bit worse in a very hot period. (3 hours per kwh, so roughly 8 over 24 hours, or £1.60 in electric at 20p). I would imagine in a warm summer it would cost less in the gas used potentially at 99p a litre, and a litre being 500g.

 

[Barchetta47]

You don't need the other options if you have a fridge that runs reliably and efficiently off 12v. Especially if you have solar

By the way, my house compressor fridge is 21 years old, ie it's been running for 21 years continuously and never broke down you'd probably need half a dozen absorption fridges to achieve that

Nope 21 year old absorption fridge still running strong!! Well it’s had a couple of valves and a thermocouple and at one point was known as the F’ing Fridge

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[HKF]

I must be a total tight wad…….
Just before I start the van…. I fill it he fridge with frozen food and everything else ice cold….. Free power from battery all the way to our destination

That's what I do. I don't see the point of pre-cooling when you then have the door open while you're loading it

 

[gpat]

I must be a total tight wad…….
Just before I start the van…. I fill it he fridge with frozen food and everything else ice cold….. Free power from battery all the way to our destination

The power that is used by your fridge on the road is probably the most expensive of all. It's is using a diesel engine that is using fuel that has customs charges on it driving an alternator.

I fill my freezer with pre frozen ready meals either home cooked or bought. It certainly will help to reduce the cooling costs whichever source you use.

It won't because you have already paid to cool them in your home fridge.

That's what I do. I don't see the point of pre-cooling when you then have the door open while you're loading it

 

[Richard n Ann]

Nope 21 year old absorption fridge still running strong!! Well it’s had a couple of valves and a thermocouple and at one point was known as the F’ing Fridge

21 years continuously? I was careful to include the word. Impressive if so

 

[steve69]

It won't because you have already paid to cool them in your home fridge.

Which is a tiny fraction of what it would cost to freeze them in your van freezer. Especially so on gas.

 

[Razamataz]

So to sumerise…….
I’m dead right

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[gpat]

Which is a tiny fraction of what it would cost to freeze them in your van freezer. Especially so on gas.

I'm not sure it would be a tiny fraction. It might be slightly less.

 

[Barchetta47]

21 years continuously? I was careful to include the word. Impressive if so

Ah got me there, just speed read! However for the last 3 years it’s run for over 180 days a year. I’m hoping it’s got another 10 years left. Damn you’ve made me say it now

 

[Minxy]

So to sumerise…….
I’m dead right

You must be a ghost then to be able to continue posting!

 

[Lenny HB]

That's what I do. I don't see the point of pre-cooling when you then have the door open while you're loading it

Blimey how long do you leave the door open when loading?

 

[Pantouffle]

What you don’t want is to cool fridge freezer day before you leave, load with food, then just before you leave, find there was a power cut during night. So have a load of half defrosted stuff just as you go.., I now put frozen stuff in the day we leave.

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[Minxy]

Blimey how long do you leave the door open when loading?

Not met yet hubby have you ... it takes him ages to pack stuff into the freezer, I do the fridge stuff in about 10 seconds.

 

[Clive Mott]

Use leccy

 

[Richard n Ann]

What you don’t want is to cool fridge freezer day before you leave, load with food, then just before you leave, find there was a power cut during night. So have a load of half defrosted stuff just as you go.., I now put frozen stuff in the day we leave.

If there's a power cut you can switch it to gas. But the house freezer will defrost

 

[LostInSpace]

If there's a power cut you can switch it to gas. But the house freezer will defrost

No, it won't. I have it on Sterling Power batteries.

 

[Knuckle dragger]

So, I need to cool the fridge on my drive prior to a trip.

LPG @99p per litre Fridge consumption 468g in 24 hours
Mains electric @ £0.225 per kwh power consumption - 240W

I could probably work it out but I'm not totally confident in my maths and electric understanding.

Appreciate some other input.

I keep some old plastic ice blocks in my freezer that chill the fridge quickly

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[mohobot]

Having just undertaken major keyhole surgery (through the vents) on my Thetford fridge to replace a kaputt 240V element (& 12v whilst I was at it) I can confirm using gas would be much easier to maintain, in terms of replacing parts without having to remove the fridge, on my vehicle!!! However as others have said, you are using on board resources if you use gas. Gas is more effictive on a 3 way fridge as it gets the heat combustion chamber hotter than the 240v element does. The 240v element gets really hot though, mine lasted 9 years of heavy use!

 

[vintageb3]

I was brought up to believe every penny counts. It's ruled my life ever since and to be fair has done me well.

I was brought up in Scotland where two of my fellow countrymen fighting over a penny, and whilst pulling said penny, invented copper wire. I have to say that I’m the tightest, most frugal sweaty sock up here and you make me feel extravagant at the very thought of pre cooling a fridge on electric. Do you shop at Tescos? Every little counts!

 

[Richard n Ann]

I can be quite tight sometimes, not because I'm short of money, no I enjoy it .

It's a great feeling when you get a quality item at a bargain price

 

[vintageb3]

I can be quite tight sometimes, not because I'm short of money, no I enjoy it .

It's a great feeling when you get a quality item at a bargain price

Oh! I agree!!! I’ve been known to dance around a flag when someone I don’t know gets a bargain. I too enjoy saving money and apart from pulling VXmans leg…I too have anxiety plugging in the EHU to cool the fridge. As stated previously…it’s because I’m Scottish and worst still….a Fifer

 

[Rapido925M]

The power that is used by your fridge on the road is probably the most expensive of all. It's is using a diesel engine that is using fuel that has customs charges on it driving an alternator

100hp (not a lot for a diesel engine) is 75kW approximately.
A fridge is about 200W which is 0.3% of the engine power.

If you use a gallon of fuel at £6 per gallon then the fridge will cost you 18p

Gordon
(ALL figures are VERY approximate )

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[gpat]

100hp (not a lot for a diesel engine) is 75kW approximately.
A fridge is about 200W which is 0.3% of the engine power.

If you use a gallon of fuel at £6 per gallon then the fridge will cost you 18p

Gordon
(ALL figures are VERY approximate )

Its just for fun.

Your calculation has a large error. You are assuming both the engine and the alternator are 100% efficient. That is in turning fuel into energy and motion into electricity. In reality the engine is maybe about 40% efficient and the alternator maybe 50%.

That quadruples your cost straight away.

I reckon in terms of efficiency in cost the order is

1. Mains electricity.
2. Gas
3. Powering from the engine.

My point was that running your fridge while driving is not free. I agree it's not big money, but we were discussing pence anyway. In comparison it's the worst. I agree it's a small %

 

[peterc10]

I was brought up to believe every penny counts. It's ruled my life ever since and to be fair has done me well.

But remember the saying, "penny wise, pound foolish"

With fewer garages nowadays selling LPG that means that you will probably have to go out of your way to pick up the gas you want, so how much extra diesel will that cost you?

The only "free" power comes from the sun. The rest you have to pay for somehow

 

[Coastal Cruiser.]

Cooled mine down once by the van batteries switched to 12v left it a few days then went back in and I think it had gone from 420 down to under 150 or there aboutalways used gas after that but I had a large gas tank and would only fill it once a year while in Germany.

 

[BillyKontiki]

LPG at 99p a thing of the past up hear now £1.30 per L.

 

[The POPs]

I agree. Refilling with gas is a faff. I use mains when I'm pre-chilling the fridge before a trip.

Even with those numbers, I don't think you've got all the info you need. On electric, it won't be using 240w continuously. Once it's cooled down, it'll toggle on and off as required.

If you assume electric is on all the time, it'd be £1.30 for a day on electric and £0.91 for gas. So worst case, there's not a massive difference. In reality, I suspect electric is cheaper.

Having a motorhome permanently based in Portugal Algarve, the cost similar to UK, when it comes to GPL (LPG), and elecs’ on sites not high on Amps.
Either way, My wife says (and always right), that the fridge freezer is far more efficient on LPL, than on Electricity. Full Stop

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[meanders]

By the way, my house compressor fridge is 21 years old, ie it's been running for 21 years continuously and never broke down you'd probably need half a dozen absorption fridges to achieve that

I don't agree.

I helped remove an Electrolux absorption fridge last year that was bought in 1973 and they had the receipt to prove it. It was still working but they were having a new kitchen so treated themselves to a new Beko fridge that has had to be replaced twice! No moving parts in an absorption fridge.