how to run fridge and freezer at max efficiency?

Jolaaled

I've recently received an energy monitor and am already addicted to my new 'toy' and have spent the day taking readings and generally flicking light switches to log the difference in consumption.

I've have already had a 'light bulb' moment (ES of course!).

Both my fridge and freezer (old and basic models) are turning themselves off and on A LOT..They are both in unheated kitchen, but seem to turn on regularly, about every 20 mins or so.

Does this mean that they're on their last legs..or need defrosting..or what?

How can i make them run more efficiently (I keep my Freezer fully packed as thought it made it more economic).

Any tips would be great.

THANK YOU!

good_advice

Hi Jo, I have also noticed my fridge and freezer turn on/off.
To make then run more efficiently I would open and shut the doors as quickly as possible. Sometimes I see OH open the fridge door to make a sandwich....leave the door open..... he says to put things back! by then all the cold has gone from the fridge allowing the warmer air in.

I would not have the cold items fridge or freezer standing next to the hot oven!

As for defrosting - invest in a energy saving frost free model.

MillicentBystander

Replacing a working fridge freezer with a brand new one to 'save' money on electric can be a silly solution. How much for a new fridge freezer? £350? That would pay for an awful lot of electric (actually it would pay for approx 3500kwh, which is more than the average household uses in 12 months).

SYNERGY

good_advice wrote: »

Hi Jo, I have also noticed my fridge and freezer turn on/off.
To make then run more efficiently I would open and shut the doors as quickly as possible. Sometimes I see OH open the fridge door to make a sandwich....leave the door open..... he says to put things back! by then all the cold has gone from the fridge allowing the warmer air in.

I would not have the cold items fridge or freezer standing next to the hot oven!

As for defrosting - invest in a energy saving frost free model.

As Millicent said ^

I would not have the cold items fridge or freezer standing next to the hot oven!

Conversely, don't put it where it may get too cold.

I know it may sound daft but most fridges / freezers sold in the UK will stop working at low ambient temperatures such as in an out house or garage at temperatures seen last winter.

Main culprits are fridge/ freezer combinations where there is only one adjustable thermostat which is in the fridge compartment, though it can also occur with freezers.

rogerblack

Cycling on and off is quite normal.
Get something similar to http://www.ebay.co.uk/itm/Energenie-Energy-Saving-Power-Meter-/320503970289?pt=UK_ConsumerElectronics_PowerAdaptors_SM&hash=item4a9f8679f1

Unfortunately, whole-house energy meters aren't so great for measuring individual appliances.
One of the above lets you measure each appliance, and - for example with freezers - tell you exactly how many kWh it's using per day.
This means you can directly see how much it'll save replacing it with another model.

There are freezers rated for operation down to 10C, but they are comparatively rare.
http://www.appliancesonline.co.uk/product/RCNAA53P-Hotpoint-Chest-Freezer-White-14752.aspx is an example.

The above runs every 41 minutes for 8 minutes. (at the current temp)

Keeping the freezer halfway full does in fact save energy over it being empty.
But much more doesn't help, and will mean you can't fill it with random bargains.
Overall, the freezer is probably costing you worst-case 60 quid per year - it won't be much more.
The savings from one really good offer on frozen food can easily exceed this if you can buy a lot.

Ally74

Jolaaled wrote: »

I've recently received an energy monitor and am already addicted to my new 'toy' and have spent the day taking readings and generally flicking light switches to log the difference in consumption.

I've have already had a 'light bulb' moment (ES of course!).

Both my fridge and freezer (old and basic models) are turning themselves off and on A LOT..They are both in unheated kitchen, but seem to turn on regularly, about every 20 mins or so.

Does this mean that they're on their last legs..or need defrosting..or what?

How can i make them run more efficiently (I keep my Freezer fully packed as thought it made it more economic).

Any tips would be great.

THANK YOU!

I got a brand new Fridge freezer earlier this year and have noticed it turns off and on a lot - like yours around every 20 mins - even though it's not been opened for a while. The thermostat is as low as i can get it.
Since i got it i have noticed we now use 1 unit of electricity through the night whereas before we didn't.

I thought it was just normal as it is slightly bigger than our older one but i'm not so sure i can do anything to find out for sure.

Ken68

This from TheYellowHouse...

http://theyellowhouse.org.uk/themes/appli.html#a14

Re-insulating fridge/freezer. Seems a bit extreme, an old eiderdown would maybe do the job.

Jolaaled

rogerblack wrote: »

Cycling on and off is quite normal.


Keeping the freezer halfway full does in fact save energy over it being empty.
But much more doesn't help, and will mean you can't fill it with random bargains.
Overall, the freezer is probably costing you worst-case 60 quid per year - it won't be much more.
The savings from one really good offer on frozen food can easily exceed this if you can buy a lot.

Some very useful comments..thanks everyone.

The energy monitors that measure the whole house aren't that accurate..however they can give a guide.

I've discovered that my fridge (when the thermo kicks in) uses 20 times the energy that 1 Energy saving light bulb uses,

whereas my freezer uses 30 times!! Guzzler indeed!!

Do you think regualar defrosting would help it be a lot more efficient?

gterr

I'm interested in this, particularly the effect of room temperature on fridge and freezer running costs.

We've bought a new freezer and can put it either in the utility room (which is often very warm because it has the boiler, washing machine and tumble drier in there and is well insulated), or we can put it in an unused downstairs shower-room where we have turned off the underfloor heating (so it's unheated).

Which would be best?

ic

A fridge freezer will always need to turn on and off, if the surrounding environment is warmer, heat will inevitably leak. The rules are simple:
- don't over stock a fridge, there should be room for the air to circulate.
- don't leave the freezer empty, the fuller the better.
- always allow warm food to cool completely before putting in the fridge or freezer.
- shut the door quickly, don't leave it open - after all the cold air inside simply falls out (this is where chest freezers can be better, however this is one reason why freezers have drawers).
- defrost the freezer compartment from time to time.

Most fridge freezers have only one compressor to cool both compartments. If the fridge freezer is in a very cold space (cellar, garage, shed, etc), it can actually stop cooling because it sees the fridge compartment as having reached the same temperature as the outside. Unfortunately this means the freezer stops freezing - so warms up! There should be good air circulation to allow the heat to move away from the back (this is essentially the heat that has been removed from inside), certainly ensure it isn't pressed up against a radiator or on top of underfloor heating!

rogerblack

Jolaaled wrote: »

Some very useful comments..thanks everyone.

The energy monitors that measure the whole house aren't that accurate..however they can give a guide.

I've discovered that my fridge (when the thermo kicks in) uses 20 times the energy that 1 Energy saving light bulb uses,

whereas my freezer uses 30 times!! Guzzler indeed!!

Do you think regualar defrosting would help it be a lot more efficient?

The momentary energy usage is not important.
What's important is the time it's on, times the energy usage.
A plug-in monitor that you plug the appliance into like I linked earlier in the thread will do this.
Or, you can do it yourself.
If, for example, the freezer uses 200W, and turns on every 50 minutes for 10 minutes, then its average power use is 200 * (10/50) = 40W.
40W*24h = 1kWh.
The switch on 'spike' - if any is unimportant - look at what the use is a few seconds later.

Defrosting reduces the consumption of fridges noticably.
Freezers, not-so-much, unless they have very very thick frost, more than a centimeter.