Using a chest freezer as a fridge

[Sparks]

Hi,

We have an upright fridge in our garage as an overflow fridge. It seems to have died - apparently it went BANG!

We also have a chest freezer, I assume if I can control the temperature inside this to about 4-5 degrees C, I can use this as a fridge?

Where can I get a plug in thermostat, that will control a freezer? I found this

it appears to be made to control a heater, so it will come on when it is too cold, rather than the other way around - any ideas? (I would open this up and extend the wiring for the thermistor, then place this in the freezer) The manual makes reference to it clicking, so I assume it has a relay, I could swap the relay out for a N/C I suppose, but if I can avoid this hassle, I will - any ideas people!?

(I really can't be arsed with taking the freezer apart and playing with it's controls either!)

Ta

Sparks...

[Bob Minchin]

How about using a timeswitch to turn the freezer on for a few minutes every hour or so. You may have to experiment with the on period to find an acceptable temperature and you will have to increase it a bit during the summer to compensate for a higher external temperature. You could always fit a fridge stat instead but that might be more effort than you want to make?

Bob

[Sparks]

I suppose that might work, Trouble is, the time switches I have only have 8 on/off times, I will need at least 12 :-(

I don't really want to change the stat in the freezer, as we only want to use it as a fridge over the Christmas period, then it will be turned off, possibly used as a freezer at another time.

Sparks...

[Clive George]

Over christmas, assuming you're in the UK, won't it be pretty cool inside the garage anyway? In which case you could either:

a) Not bother b) Use the freezer as a big unpowered cool box - stick some bottles of ice in (2L lemonade bottles work well for this) c) Run it manually since the required duty cycle will be very low

cheers, clive

[Pete C]

Hi,

If the thermostat in the fridge is still working, box it up and use that. With a bit of luck it will have a capilliary so the sensor 'bulb' can be in the freezer with the rest of it outside.

cheers, Pete.

[Peter Parry]

Freezers (and fridges) don't measure cabinet air temperature as they would cycle on/off far to often and this dramatically shortens the life of the compressor. They usually sense the evaporator plate temperature and the thermostat has a lot of hysteresis to stop short cycling. You need to emulate this behaviour.

Use a timer as suggested - on for a time once every few hours should be fine (particularly with a chest freezer) if the cabinet is about

2/3 full. If its emptyish put a bucket full of water in to freeze and act as a cold store. You will have poor air circulation and the probability that stuff on the base will freeze and on top be a bit to warm. If its mainly drinks it won't be too much of a problem, if its leftover turkey take care.

[Peter Parry]

If they are relay output simply wire two in parallel to give you 16 switching times.

[meow2222]

There shouldnt be any need for a fridge this time of year. Just keep using the dead one.

NT

[Galaxy]

After a few days it will smell like there is a corpse in it and the food would have to be chucked out.

[meow2222]

Mine was fine switched off all winter, year after year, so why would the OP's starto to stink? Unless of course there was a dead corpse in it...

NT

[Scabbydug]

You'd get a hell of a fright if there was a live one in there :0)

[John Stumbles]

You wouldn't want a live corpse in there.

There was a wibble somewhere (down under IIRC) where some ecofreak had wired a chest freewer as a super-efficient fridge.

Trouble with mechanical thermostats is the hysteresis (sp?). I tried running a fridge off a cylinder stat but it would either get too warm before coming on or too cold before switching off. You'd really need an electronic stat (or mechanical with accelerator heater) to get it down to just a degree or so between switch-on and switch-off points.