Fridge and ambient temperature

We recently bought a new Daewoo 500 litre fridge, which had an advertised energy consumption of 520kWh/year (all fridges here are measured to an Australian standard so it's possible to compare). Of course I popped the power meter on it and left it running for a few weeks.

I found ambient temperature had a big effect on the energy consumption. Through a recent heat wave (5 days over 37C outside) the inside temp hit 27C for a few days. The fridge was using about 700 kWh/year. Guess it was also used a lot was we were drinking more and eating lots of ice blocks!

As the inside temp cooled the average power dropped beneath 600 kWh/year. So I figure we need to get closer to 20C inside to get the stated energy consumption.

- David

icarus75's picture

Last year I collected some data on our old and new fridges' electricity consumption. Your post triggered me to dust off the data and pretty-print it into a chart. I've shrink-wrapped the chart into this blog post.

Cheers,
Bart.

drowe67's picture

Wow Bart 161 kWh/year is really low!

I don't think there are any fridges we can buy here that are that low (even the smallest bar fridge). Our 15 year old fridge was at about 1000 kWh/year but then towards the end it really died and was at 1700 kWh/year (4 kWh/day).

Our new fridge is two door 524 litre fridge/freezer. We really had to hunt around to get a fridge that low - most are 700-800 kWh/year in the same size, and we paid perhaps 50% more.

The Australian government database of products might be useful for others, as I imagine the same products are shipped all over the world:

http://www.energyrating.gov.au/appsearch/default.asp

I just searched the database and the best two door fridge/freezer is a 400 litre, 349kWh/year. The best single door fridge above 200 litres is a 350 litre unit at 226 kWh/year. No too bad I guess.

I noticed the database has introduced a new "energy star" rating and my new fridge only ranks half way on that scale. Looks like our government has recognized we have a way to go, which is good.

Horror story: My Mother in law runs 5 fridges and freezers, all of them in the 15-20 year old class. She thinks it is better to buy food on special and freeze it to "save money". Her last bill was $1000 for 3 months, which is (1000/0.2)*4 = 20MWh/year or 55kWh/day!

- David

skynetbbs's picture

You probably talk about those "american fridges"...
although you can buy them over here... mostly for it's Icecubemaker...
most people use a fridge and a freezer (seperatly) and 1 door each...mostly the vertical models...although horizontal freezers exist...

A Siemens Freezer vertical of 333 l consumes 260kWh/year
and a normal "fridge" vertical of 390l consumes 148kWh/year

source: www.krefel.be a nice shop that adds these info to their equipment...allways nice if you are looking for a new led tv ...."size does matter"... the bigger the tv the more it consumes...

drowe67's picture

OK so thats 723 litres combined for 408kWh/year for a standard fridge + freezer in Europe. Or 0.56 kWh/year/litre.

My new fridge/freezer (which is better than most available here in Australia) is 603 litres total for 515 kWh/year or 0.85 kWh/year/litre.

So we are about 50% behind in efficiency....(sigh)!

bazzle's picture

My new 430 litre Electrolux is about the same as the efficient one on the graph. My prev Figidaire was similar to the old one as well.

Bazzle

fusionpower's picture

My brother-in-law related a tale of woe re his fridge/freezer.
He was getting $1200 quaterly electricity bills and was convinced my sister was running the electric heaters all the time. This went on for over a year when finally my sister pointed out to him that it was unlikely that she would be using the electric heaters during a 45 degree summer. :)
So they went around the house switching off everything (except the fridge/freezer) and the electricity meter was still spinning like a mad thing. He went inside and switched off the fridge/freezer and the meter stopped.
Turns out they had set the temperature on the fridge/freezer to a temperature that it was unable to achieve resulting in the compressor running constantly, no cycling.
The compressor was so quiet they never realised it was always running.
They adjusted the temperature up a few degrees and now their bills are around $500 a quarter.

Beware of fridges. :)