Thermostatic 13A Adaptor

David snipped-for-privacy@btinternet.com posted

Most ordinary room thermostats will do this, it's just a question of taking the appropriate output from the terminals. At least non-electronic ones do; don't know about electronic ones.

on 03/02/2021, David supposed :

I bought one of these, to precisely maintain the temperature of my

Don't you need something which senses the temperature *inside* the box? The one you cite won't do that.

You can get room stats which have external sensors, which you could probably put inside the box. How much power does the box take? Check that it's within the switching scope of the stat. The one you cite claims to switch 13A - but most room stats have a far lower rating than that.

All the oil filled ones I've seen have an adjustable thermostat. Brian

Ah! I recognise that one from Amazon - the reviews about electrical safety were scathing to say the least. So I think the word "strictly" is doing a lot of heavy lifting in your description. ;-)

I also forgot to mention that the beer fridge is outside but under shelter, which I don't think would make much difference as I have normal electrical devices out there without any issues.

As for the thermostat don't think that it is feasible to run the cable under the lid as the seal is a thin raised plastic strip in the base which fits into a recessed rubber seal in the lid. A bit like the seal on some plastic food storage tubs. So it isn't like a thick soft rubber seal which will deform over a wire but allow the lid to shut and fully seal.

Thanks for the link, though.

Cheers

Dave R

Something like this might work if your fridge is < 250 watts

David submitted this idea :

Have you a link to the one on Amazon, I was unable to find it.

The one on ebay is a knock off of the very much more expensive inkbird one.

The ebay one I saw (also on amazon) has an integral 'deathdaptor' the inkbird seems to have a trailing two-gang 13A socket with separate heating/cooling?

on 05/02/2021, Andy Burns supposed :

It depends on the Inkbird model.

It says 'no reviews' in that Amazon link. The obvious UK regs issue is the lack of shutters on the 13amp socket.

on 04/02/2021, David supposed :

I don't really see any controller being able to work very well, without being able to 'see' the temperature inside.

I would see if there's a corner you can drill to put a probe through, and then seal with expanding foam to insulate.

(assuming it's a standard fridge and not a water bath/etc)

Theo

From the original post, it was the *external* temperature that was being monitored. Probably only turning the coolbox on when the weather was warm enough to bother.

I assume that the idea is not to have chilled beer, but to prevent it being overly warm on hot days.

Might it be possible to add proper thermostatic control to the coolbox though? Presumably a small hole in the lid (usually only plastic and insulation) would let a thermocouple or RTD be fitted and a simple on/off temperature controller fed by that.

The draw is 0.6A on the 240V adapter to 12V. This is a cigar lighter adapter for camping ans the cool box is 12V.

So not a big load.

Cheers

Dave R

External temperature is all that I am after.

If it is below, say, 4C outside then there is no reason to run the cool box and because there is no thermostat the inside can freeze at times.

Summer it runs all day. It is shoulder seasons where the temperature drops at night but goes up during the day I am trying to refine.

I don't want to mess with the cool box itself because it also travels with us when camping or caravanning.

Oh, and it does provide chilled beer. :-)

Cheers

Dave R

Use the room thermostat solution I suggested (connect it in series with the cool box's power cable). I use this method to extract heat from our conservatory, which gets very warm on sunny winter and autumn days, and can be used with a suitable fan to help warm the main house.

You could make up an additional outer box out of 100mm celotex offcuts (that regularly seem to fill up skips) and keep your coolbox inside it for more effective temperature control.

I have an offcut of 50mm PIR loosely 'stuck' to side of my Liebherr fridge freezer and if I move it the outside skin on the fridge beneath this offcut is noticibly colder.