How do fridge freezers ever work?

Take the standard fridge freezer - one thermostat (in the fridge half) and one compressor.

Assume expected ambient room temperature of 20C.

Fridge kept at 5C by thermostat.

Temperature difference between fridge and room is 15C.

Freezer is -20C at this room temperature.

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Now assume the sun is shining into the kitchen, or the oven is on. The room gets to 30C.

Fridge still kept at 5C by thermostat.

Temperature difference between fridge and room is now 25C, so compressor is working 1.67 times harder.

This means the freezer/ambient temperature difference must be 1.67 times larger = -36.7C. I guess that's not really a problem, but wastes electricity.

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But what if the kitchen goes down to 10C at night? Who heats their kitchen in winter at night?

Fridge still kept at 5C by thermostat.

Temperature difference between fridge and room is now 5C, so compressor is working 0.33 times harder than the original 20C room.

This means the freezer/ambient temperature difference must be 0.33 times larger = -3C. Not acceptable for frozen food. How do the manufacturers get away with this?

Reply to
Undersized hippopotamus
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My kitchen never gets below 17C so not a problem.

Many modern fridges now use a twin coil system for better control of each compartment. I have a Samsung that can have three zones individually controlled. A drawer above the freezer can be set for normal refrigerator setting or for freezer.

Reply to
Ed Pawlowski

I want a for Christmas...... as the song goes.

I thought all Canadians kept their food in a hole in the permafrost?

Brian

Reply to
Brian Gaff

Undersized hippopotamus formulated on Sunday :

Very unlikely here, we are too well sealed up and insulated. According to my log for yesterday and last night. Maximum temperature in the kitchen 20.2C, dropping to 17.7C at 7am. Outside fell to -1.9C at 7am. The heating system was shut down at 22:30, we retired early due to the

25 hour day.
Reply to
Harry Bloomfield

Hmm, well I only intended to include his screen name animal but Windoze decided differently, but there you are. Brian

Reply to
Brian Gaff

never knew it was a problem .......

Reply to
Jim GM4DHJ ...

So the one compressor can be diverted with valves like central heating? I though that was impossible due to pressurisation and they'd need two compressors.

Reply to
Undersized hippopotamus

Christ that's some insulation.

Reply to
Undersized hippopotamus

I don't live in Canada.

Reply to
Undersized hippopotamus

There's a lot of complaints all over the internet.

Reply to
Undersized hippopotamus

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