I want to move my stack of paint tins (and perhaps other chemicals) from the garage to the shed. The shed won't be heated, so they might freeze. I am considering this idea although I am almost certainly not going to bother. This is just an idle thought:
I started wondering if I could take an old fridge and modify it into a heat pump, to keep the contents above freezing. Obviously I don't want to be messing about with refrigerant, so I thought maybe I could cut the back wall off a fridge and build an enclosure out of plywood and Kingspan with the fridge back panel mounted the other way round so the evaporator is on the outside and the condenser on the inside. Then modify the thermostat so it keeps the enclosure above freezing. It'd be really efficient. The most expensive part would be the Kingspan cos that's pretty pricey these days.
Whaddya reckon? Genius or insanity?
Sounds like genius to me. But will the refrigerant work at the correct temperature? Fridges aren't designed to chill their contents below zero; and you're wanting to extract heat from outside when its below freezing. Maybe use a freezer? Or maybe fridges and freezers have the same refrigerant anyway and it'll work fine.
Save on the Kingspan by simply cutting the back wall off the fridge and flipping it round, then sticking it back on with duct tape or something. Tada! Inside out fridge.
I like the idea.
Whaddya reckon? Genius or insanity?
Insane genius. Pics please.
Wouldn't it stop operating when the air temperature (fridge "contents") gets colder than it's lowest set point (2deg?)
I see that it would keep your tins warm on a warm day, but do nothing on a freezing day
Put the paint tins in the fridge and set the fridge to 4 degrees? Cold paint but not frozen.
Or put paint into the fridge and don't turn it on? insulated paint box.
That, why do Eskimos buy fridges? To stop their food from freezing.
+1 for it needing to be a freezer
Some fridges have the cold plate built into the side walls too, so you'd need to find one with a separate freestanding cold plate.
You'd need to deal with it icing up. I suspect to shift any meaningful amount heat it would need to large cold-sink, like a water butt filled with anti-freeze. Because if the air drops <0C then your cold plate will be covered in ice and won't defrost.
Or put paint into the fridge and don't turn it on? insulated paint box.
That would be way less effort.
Stick a 60W greenhouse heater on a thermostat in with them if you're worried (and none of the paints are oil based). Or even less effort, just put a 120 or 180W greenhouse heater under the shelves. It'll cost more to run, but the amount of work you're considering would still take years to pay off.
Or .......... just bin the paint. After a few years it's probably already gone off, or the paint on the walls has faded. You may as well just buy fresh paint when you need it, think how much that shed costs or how much of the mortgage is going on the garage to store a few quid's worth of paint dregs!
Save on the Kingspan by simply cutting the back wall off the fridge and flipping it round, then sticking it back on with duct tape or something. Tada! Inside out fridge
Yeah I thought of that but fridges are usually quite small and the shelves are awkward etc etc. Unless I could get a big American sized one.
Wouldn't it stop operating when the air temperature (fridge "contents") gets colder than it's lowest set point (2deg?)
Yes, I'd have to hack the thermostat, but shouldn't be too hard.
Fridges aren't designed to chill their contents below zero; and you're wanting to extract heat from outside when its below freezing. Maybe use a freezer?
Yes, yes, good thinking. Should be just as easy to find. That said, traditional fridges have a freezer compartment that gets below freezing. And someone was offering up a working fridge up the road yesterday for free. But it's too soon, the shed's not done yet.
Or put paint into the fridge and don't turn it on? insulated paint box.
Mmm yeah possibly, would probably work ok, it's not exactly cold down here anyway.
Because if the air drops <0C then your cold plate will be covered in ice and won't defrost.
Yes, the cold side would ice up but it's very rare for the temperature here to be below freezing for more than a night, I think I can only remember that happening once in 18 years and only then for a day. So as soon as ambient temps go above 0 it'll all melt. I would need to deal with drips though.
just bin the paint
No, we regularly use it for touch ups and whatnot.
Build your kingspan enclosure and fit an old school 40w lamp bulb inside.... It will heat the box up nicely.
For added geek you could have a simple thermostat.
It's incredible the lengths some people will go to avoid decorating. 🤣
Lady Molgrips .." When were you thinking of making a start on the decorating?"
Sir Molgrips .. " Just as soon as the paint is at the correct temperature, can't rush these things".
Having said that,I do want to see the modified fridge/ freezer 😉
Just use the case and put a thermostat controlled heat mat in the bottom of it.
but it's very rare for the temperature here to be below freezing for more than a night, I think I can only remember that happening once in 18 years and only then for a day
You've answered your own question. If it is rare for below freezing episodes just put them in an insulated box, add a small heater that will be on once in a blue moon by the sounds of it if you are still concerned. Use a probe thermometer in the box to switch heater on if needed.
Yes, the cold side would ice up but it's very rare for the temperature here to be below freezing for more than a night, I think I can only remember that happening once in 18 years and only then for a day. So as soon as ambient temps go above 0 it'll all melt. I would need to deal with drips though.
Misses the point that the cold plate from a freezer will be significantly colder than the ambient air. If the air is 0C (the only time the system needs to be on) then the plate will be nearer -30 and would quickly condense any moisture in the air until it could no longer transfer any heat.
It's why air-source heat pumps are great in Autumn and Spring and save their owners a fortune. But cost an arm and a leg to run for those Mid-Winter months. They struggle when the dew point is around or below zero.
fit an old school 40w lamp bulb inside
Have you tried getting hold of one of those lately? And besides, you are missing the point.
Find a scrap yard with an electric car. Remove the heat pump and use that
This has inspired me.....
Not to try and reverse a fridge unit, but to build myself a paint cupboard out of a Freecycle chest freezer and install a small heater unit (I think I've got one of those small low power units intended for a greenhouse somewhere. And add a thermostat.
It's why air-source heat pumps are great in Autumn and Spring and save their owners a fortune. But cost an arm and a leg to run for those
Are you sure about that? Why does the dew point affect the efficiency?
Any heating system costs more to run when it is cold.
Heat pumps will cost more too, but if your system is designed correctly, used properly and on the correct tariff, then running costs will be comparable to gas for the winter months.
The problem with ASHP in the UK climate compared to the Scandinavian countries is the high humidity we get with cold temperatures. Cold in itself is not an issue but coupled with humidity levels the performance is impacted much more.
@molgrips Fun project idea, have you seen this vid?
Same kind of thing but the other way round.
To the nay-sayers ... obviously there are a tonne of easier ways to achieve the same result but where's the fun in that?!
No, we regularly use it for touch ups and whatnot.
we are all missing the point - what are you doing to your walls ......
And besides, you are missing the point.which is what - to make things as difficult as possible?
😉
