Best part: every fridge in every house already does this. You just collect the money!
The pic suggests adding a fan but that will actually cause less heat output, since the fridge will be more efficient at maintaining inside temperature with heat removed faster from the condenser. The difference is slight though, since the refrigeration system’s waste heat (equal to its power consumption) is a small part of what exits the condenser, the rest is compensating the heat that seeps into the fridge by imperfect insulation (and does not heat your home anyway) plus a little bit for cooling recently-inserted warm things.
That’s… Kind of what it already does though. It’s just that it’s not cooling the inside enough to heat very much of your house.
Why did I have to scroll to the bottom to find this? Like, where did you think the removed heat was going otherwise???
Heat is stored in the microwave.
The heat is moved outside the environment
The heat also came from that environment in the first place. So a fridge doesn’t actually heat up a house (ignoring the negligible losses)
Not so negligible! If your fridge draws, say, 1500 W while it’s running, then it releases 1500 W of heat into your living space PLUS the heat it’s removing from its interior. That’s pretty substantial while it’s running! But hopefully it’s not running full-tilt 24 hours per day lol
A fridge definitely doesn’t draw 1500 W continuously. You might be thinking of the start-up surge power draw
My double-door draws 300 W while the compressor is running (average power is obviously a lot less than that)
That would be one hell of a fridge if it did! But my number was meant as an illustration of how the math works, not necessarily accurate to any specific refrigeration device.
Wow, I wooshed myself even harder than they to whomst I was replying. Good job me.
HVAC is just the Patrick star push the city meme with heat
Woosh
They literally do that already. Heat doesn’t vanish from your food. It’s moved from the inside of the box to the outside of the box.
It’s an air conditioner built into a cooler.
that’s the joke. i tried to imply it in the title but i didn’t realize that in english you call it 2nd law of thermodynamics rather than 2nd rule
Yea I guess that should have been obvious to me. Sorry.
It also won’t put out much more heat than is already in the room. It evacuates heat from it’s interior, heat that was already present in the room. If the room was colder than the inside of the fridge, it wouldn’t produce any heat at all. the thermostat would cut off after the temperature equalized and it wouldn’t run at all.
When it does run it produces maybe a few dozen watts of waste heat. Definitely not useful to heat a space with.
Where are you getting “a few dozen watts”? I see ranges of 300-800 W online.
I guess that makes sense, although unlike a 200w heater it doesn’t get warm as quickly. And so won’t make a great heater. I guess it will ultimately put out that much heat over time though.
My refrigerator has 200w of draw and most of that goes into doing the refrigeration, so a few dozen watts of waste heat is my estimate based on my refrigerator. Which isn’t a big refrigerator, it’s definitely on the small size. A bigger refrigerator with a more powerful compressor will produce more waste heat but it’ll still be small compared to the energy put in to do the work. And it’ll be tiny compared to the wattage of a heater which top out at 1500 watts.
Oh, I see what you’re saying!
That’s not quite how refrigerations works. The energy doesn’t “go into” doing the refrigeration; the energy you’re bringing in from the electrical grid is still in your home.
In other words, if your fridge runs at 200 W, then your home is being heated at 200 W, plus whatever heat is being pulled from the inside of the fridge.
Okay, but hear me out. If you reverse it, you’ll have a heat pump oven that also cools your house. 🤓
Would be great for people that love yogurt.
a heat pump oven sounds like an actually cool idea. why is it not a thing yet?
The difference between oven temperature and room temperature is too high for it to be efficient. Like, a fridge is maybe cooling things 30F (~15C) maybe 50 (~25) for the freezer. An oven goes to like 500F 260C, so it would have to maintain a heat differential of like 430 (~215) degrees. Like, it’s just less efficient than a resistive coil at that point.
hmm brb imma go invent a refrigeration cycle that runs 15C <-> 250C
Fridges have always been doing that for ages. I’d rather not let them dump heat indoors and instead move the heat directly outdoors to keep my air conditioner from running too hard.
Yeah but now you’ve got to find a place to store or how to discard all the little arrows, and the orange light probably is too bright at night
No joke, I think thermal networking will one day be common in homes.
It exists to some extent already in large commercial building design if only because the business sense of the added efficiency is easy to illustrate at that scale.
i want that too. lots of houses already have hot and cold water lines so it shouldn’t be too hard. problem is getting appliances to adopt a standard on how to connect to this network
especially in areas with district heating, it’s a massive resource we’re just throwing away currently.
When I was a kid, our family dog would drag his blanket to our fridge and spend the night bundled up in front of it (where the exhaust heat was)
startup idea: fridge with warm little nook for dog
weird kitchen, if i am cooking on the stove and i want an ingredient from the fridge, i have to walk around that wall, and we know that’s something we do multiple times
I mean, it’s AI generated, so it isn’t going to make sense lol
A very “not like that” Cooking Triangle.
if you’re cooking on the stove but the fridge is next to you and pumping out lots of heat that heat may inadvertently make your food overcooked.
the startup entrepreneurs have thought this through. give them some credit.
Or the heat could be used for cooking kebab on a vertical rotisserie. Which is more convenient done away from the stove, on the other side of the wall, facing the living room.
And the fov is likely from a hallway, dining, or living room. All weirder choices for a normal fridge if you decide on a separate kitchen. Then again everything in the pic screams unthought-out/unpleasant layout of a western suburban hellscape.
I have a better idea
One system that is both an Air conditioning system that uses waste heat to heat water. And uses waste “cold” from heating water to cool house.
I can get you half way there with a heat pump water heater.
Thats the point, they both use the inverter based heat pumps, they even use the same refrigerant. By no-one builds one that shares the same unit, so they both dump waste temperature differential into the outside air.
i’ve always been frustrated by this… i want a heat pump system where you have high and low pressure refrigerant pipes like regular water pipes and have AC, fridge, hot water, and drier all just use the same big compressor outside… drying clothes in the summer with the AC running would be basically free (if you don’t have anywhere outside to hang them), using the fridge in the winter similar
having compressors for all these systems when they’re rarely all used together seems wasteful (plus, 1 big system is often far cheaper - not to mention more efficient - than 4 or 5 small systems)
A lot of newer water heaters use essentially an air conditioner type system to heat the water and blow cold/cool air away from it. Obviously only useful if you have your water heater in an area that can make use of said a/c, but I did and it was glorious.
Theoretically you could use a heat pump to heat water that would generate “waste cold”, but heat pumps typically don’t get nearly hot enough to heat water as much as a gas water heater does. I suppose one could be made but it would be very difficult, I think. It would need to use the ambient air in your house and suck enough heat out of it to heat your water, and if your house is about 72°F / 22°C and you want water at 130°F / 54°C (which is pretty typical) that seems like a challenge, especially since water is so much denser and has a higher heat capacity. I have a portable A/C with a heat pump and it starts to struggle to heat my apartment once it gets down to 45-50F outside and it struggles to cool once it gets above 95F.
the struggling to cool above 95F is definitely not a problem with heat pumps… they’re very common in australia (basically everywhere has heat pump cooling - cooling is pretty much a necessity during our summers) and we regularly get to 110F and above with no problem
GE currently sells a heat pump water heater on the market, I’m not sure if it uses resistive heating to supplement the heat pump
I have a portable A/C with a heat pump and it starts to struggle to heat my apartment once it gets down to 45-50F outside and it struggles to cool once it gets above 95F.
Your AC may be undersized if it doesn’t perform well in hot weather, also unfortunately many heat pumps aren’t optimized for extreme cold weather performance. Some are, it’s definitely not a failure of heat pumps in general, but you’ll only find those as permanent install units and they’re usually only sold up north.
Mine is general purpose, I suppose. I’m gauging its performance based on the temp of the air coming out of the unit, I think the room I’m using in is within range of it’s cooling/heating capabilities. Didn’t realize GE was making water heat pumps, nice.
Check if you can get some shade on your exterior unit. Also check that the area is well ventilated.
And as always, insulation is king.
I’m renting, I’m doing the best I can with what I’ve got. The entire unit is inside and I have a huge tube going to a panel in my window. It works surprisingly well.
insulate the tube (wrapping towels around it helps), make sure it’s as short as possible for minimal surface area, and properly seal around the window where the interface is : duct tape will work; just make sure there’s no leakage of outside air back in
that should get you an extra ~2-4C of cooling depending on the size of your space and size of the unit
also, check all the seals around exterior windows and doors too. sealing up those with various methods (duct tape, draft protection on the underside of doors, etc) can get you another few degrees
not only does it improve how well the unit works, but it should save you money whenever you heat or cool your house
The unit actually came with an assortment of very helpful insulation accessories. The tube going to the window is double-walled and it came with sheets of adhesive insulating foam for wrapping it up as well as insulating sheets to stick over the window panel. I did end up using tape (not included) to seal the gaps around the window panel. I would highly recommend this unit to other renters.
oh that sounds ideal!
Yeah, those units have their limits. Better than nothing though.
Its all just about the relative compression ratio of the refrigerant. They make heat pump based water heaters that have external units that operate identically to air conditioners running in a heating mode.
Id rather have one that sends it’s heat outside the house so my AC isn’t fighting the fridge. And reverse that in the winter.
The fridge would actually have to work harder though, to maintain a larger temperature difference between its hot and cold sides. So it’ll likely use more energy than the way fridges normally work.
In winter, if it’s cold enough outside, refrigeration may not actually be needed. You could just pump coolant between inside the fridge and an external radiator to cool it.
But, now you have a more complicated system that requires more permanent installation into the house, and also has an outdoor radiator that needs to be maintained so it doesn’t get clogged with leaves or damaged.
Not too worried about how permanent the installation is. I mean how often do you move the fridge around your kitchen? Besides, these days a lot of them have a water faucet installed for the ice maker anyway. As for efficiency, the AC has to fight the same gradient already, but with the heat being dumped inside it has to overcome it twice.
It would add complexity and points of breakage, so it would need to be a robust enough system to make it worth it, which fights against it adding enough efficiency to be worth it.
Considering that there are news about newer smart fridges displaying ads. Then as soon as that happens.
Throwing a standard fridge out the window can already be kinda difficult. Doing it to something that’s permanently installed is going to be much harder, though maybe more cathartic due to needing to use a crowbar.Oh, to hell if my fridge will ever be showing me ads. That’s some dystopian crap right there. Also, quick connects work for cooling loops.
Better avoid Samsung then, they’re the ones getting the ball rolling with this abomination.
https://fortune.com/2025/09/19/samsung-family-hub-refrigerators-advertisements/
Samsung has an amazing history of appliances bursting into flame, I was most impressed by the washing machine, so avoiding them isn’t a problem.
I’m not sure that it would he equivalent - the AC has to fight a smaller temperature difference between outside and inside.
Also, I am not sure how much it’d really save for the extra complexity. A lower maintenance way of improving overall efficiency could maybe be some way of capturing that heat to warm water a bit, so that could save your water heater some work by preheating it perhaps. That would keep all plumbing internal, and the fridge may even fight a smaller temperature difference, since tap water is usually cold. Though now if your water heater and “warm water” tank are full what do you do for the fridge?
I do think that “better insulation for the house” or “just a more efficient fridge” probably trumps any of these changes in terms of energy saving for your investment in many cases.
Apparently it’s worth it for commercial kitchens, and most marine cooling systems use external loops since the water is always there. In a home setting it looks like insulation is almost always more cost effective though.
I could see that, commercial has much larger cooling demands for big walk-in freezers etc., and in marine that makes a ton of sense.
permanent installation into the house
We have those. Built in fridges are hella expensive.
outdoor radiator that needs to be maintained so it doesn’t get clogged with leaves or damaged
Ditto. Just not hooked to the fridge.
In winter,
Weirdly, winter can require heating the fridge. Also, depending, it can be really hard on the pump. There are specific fridges made to handle garages (most people use a junk fridge and put low value items that do not require refrigeration, but are more enjoyable cold, in it.).
The fridge would actually have to work harder though, to maintain a larger temperature difference between its hot and cold sides. So it’ll likely use more energy than the way fridges normally work.
I think their idea is to still use the chill air from the room for cooling the heat exchanger of the fridge, but transporting the then hotter air outside of the house (like a proper kitchen hood does) instead of keeping it in the kitchen.
I think though that if it’s hot out, that would increase your cooling demand - moving warm air out of the fridge means pulling that same amount of air in, from outside (potentially higher temperature than the fridge exhaust). So in that case it is probably disadvantageous.
This is why I don’t think fridges should have their own cut out. It blocks the air flow
Can anyone explain why almost everyone operates a fridge inside a heated house in winter while there is “a fridge outside”. Would the fridge not need less power to cool down the insides when it’s already cold outside?
Am I really the only one in this world with a fridge outside?
- Stability. Temperature outside fluctuates, food could freeze or get too warm.
- Containment. The fridge prevents critters from getting to your food.
- Location. The fridge is conveniently located in the kitchen.
In winter I do tend to keep drinks outside if the temps are alright, they cool down faster outside than in a fridge anyway.
I am using a fridge outside: It is like a small balcony first floor with a roof and cool most of the year. So #1 and #2 are checked. For #3 I have a small Japanese compressor fridge in the kitchen, only for the very important daily things like milk. The mustard stays in the outside fridge. The kitchen fridge never uses more than 30W for cooling. But only IF it runs. So that checks #3.
This was originally what cellars and basements were for. Ground temperature was stable relative to outside temperatures, so it was warmer than freezing during winter but colder than outside during summer. Thus it could help preserve food.
Some old farm houses still have that around here. But it is outside below a small hill or a slope. Some call it Kartoffel Keller. And some still use it for long time storage.
Sometimes they’re called a “root cellar” in the US, as they were often used for storing root vegetables; carrots, turnips and potatoes. So common etymology there.
Fridge is expensive, only have one.
Fridge is large and heavy, not worth trouble of moving outside.
Waste heat from fridge go to heating house anyway with efficiency above typical resistive heater can manage before even consider double benefit of also cooling food.
Maybe someone will do the math.
I see plenty of secondary fridges outside. Rust is an issue though.
You can get fridges made for outdoor use, but I guess those are more for people who are willing to spend the extra money on having an outdoor kitchen.
if you’re already heating your home, then what does it hurt to have the fridge do a bit more of that?
in fact, the fridge is a tiny heat pump using your food as the reservoir. so unless your house is heat pump equipped, it is beneficial energy wise to keep the fridge inside.
if your house is heat pump equipped, then it depends on how the efficiency compare. if you put lots of hot food into your fridge then you should
definitelyprobably keep it inside.Don’t forget that refrigeration is costly tech magic though. Power hungry and requires toxic chemicals.
In Paris a lot of apartments had a cellar opening on the outside.
Like this one:
Unfortunately a lot of them have been removed since it’s much easier to have everything in the fridge at constant temperature and energy used to be cheap.
Real easy answer: keeping a fridge cool during a very hot summer outside requires a more powerful cooling system. Instead most people have a powerful AC since you want the house cool anyway, with a cheaper fridge cooling system
The reverse is also true. You wouldnt want your fridge to require a heater installed in it to keep your food from freezing in esspecially cold winters
Mucki said in winter.
To your second point, if I can deduce by the feddit.org that Mucki is in Germany, the winter outside temp will swing between -5° and +10°. The isolation of the fridge might be enough. But I sometimes put a stew or soup just outside on the balcony without a fridge.We have only very few days where we have extreme icecoldness around. It’s a moderate climate. I never monitored how much less power it uses outside than inside… But It stricked me that the cooling cycles are much shorter in winter after I had put it outside.
I do this in rimworld to get just a little bit more heat in winter
My house has hydronic heated wood floors. Warm water from the heater unit circulates through pipes under the floor, heating the room from the ground up. It rules. It’s quiet, even, and amazing in winter.
