More On The Fridge? Really?

The fridge post incited sufficient controversy. We start to come up against matters of theory vs. practicality. Here are two:

1) “Why not put the fridge in the coldest place in the house, instead of the warmest?” This is a good question. I can see two competing arguments: (a) It makes no sense to store things you want cold, like beer, in a room you want warm, like the kitchen; but also, (b) It seems to make no sense to keep a net-heat-producing appliance, such as a fridge, in a room where the heat it gives off of no human use, such as an unheated spare bedroom. We can all agree that cold things should be kept in cold places, and warm things in warm places– but the fridge is both cold and warm at once. So where does it belong?

My instinct on theory is to stick with the fact that the fridge is a net-heat-producing object, not a stably-cold object, so long as it’s running at all. And thus it should stay in the kitchen. If you have a place where it doesn’t need to run at all, you don’t need a fridge at all– you just need some shelves. So the whole problem goes away.

But, practicality outweighs theory on this one anyway. First, it’s obviously not so practical to have the fridge far from the kitchen (though if that was the only argument, I’d overrule it.) More importantly, it seems the average fridge/freezer combination isn’t designed to function properly in much-colder-than-usual-room-temp. See here. I can attest, in fact, that this is true: in the weeks when I had my kitchen in the range of 48-50F (9-10C), I struggled to find settings for the fridge that would keep the freezer contents frozen, without freezing all the veggies in the fridge. So. I am settling on the idea that, if you’re going to own a fridge, it’s ideal to keep it in a place that is occupied by humans, and neither too warm nor too cold. Which seems to be my kitchen.

2) This debate about whether throwing fridge-temperature water back outdoors is a waste of heat, or not. Gets mind-numbing. Gets into the difference between heat and temperature, which aren’t the same. In fact, bringing a bucket of icy water (or even ice) in from outdoors will simultaneously cool the house and add energy to the house. Amazing, but true, and due to the different heat capacities of air and water (and other materials). A liter of water and a liter of air, for example, might be at the same temperature– but the amount of heat they contain is enormously different, by a factor of over 3,000. In other words, letting the liter of water cool 1ºF will release over 3,000 times as much heat (calories, kWH, BTUs) as letting the liter of air cool the same 1º.

So, in terms of contained heat, swapping a 2L bottle of fridge-temp water for 2L worth of outdoors-temp air is muchmore significant than swapping equivalent volumes of air at those temperatures. Even swapping 2L of cold water for 2L of hot air is a bad deal, heat-wise. In fact, by my [very rough] math, to break even on the swap you’d need to get 2L of air that was approaching the surface temperature of the sun (just very roughly). Good luck finding that (and if you can, I don’t advise putting it in a soda bottle.)

Here’s another way of thinking about it. Suppose I offer you an attractive five-ton piece of solid iron which you can put in your house for the winter, or until you tire of it. This hunk of metal comes to you at at temperature five degrees lower than your current indoor temperature. It will of course have to displace an equal volume of your room-temp air when we install it, but otherwise, there is no cost to you. So– do you want it? (For reference, iron has a heat capacity about 3/4 that of water, and 2,700 times that of air.)

J. and I discussed this last night. She refused my offer. I said I’d gladly take it if she didn’t want it. This, I think, because we were considering the situation from two different angles: heat (me), and temperature (J.)

J’s argument: the relatively-cool meteorite, with its enormous heat capacity, will draw heat out of the air and all the other objects in her house. Once they reach a new equilibrium, the overall house temperature will be lower than she started with, which makes her unhappy. If she wants to get back to her starting temp, she’ll have to supply more heat to re-warm the house (and the iron), which also makes her unhappy. So, she rejects the plan, on valid grounds.

My argument: the meteorite, as is, contains a vast quantity of heat– certainly more than the warm air it will displace, and quite possibly more than the entire rest of my existing house structure and contents combined. It’s like free money. So long as I don’t dispose of the iron when it is warmer than I accepted it, it won’t cost me anything. And if I wait till the whole system (house and iron) has cooled below the original iron temperature, then I will have sucked some free heat out of it. All I have to do is remember to roll the meteorite out of the house when it’s as cold as possible– perhaps when I return from a week of vacation and the heat has been set to minimum for a week.

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9 Responses to “More On The Fridge? Really?”

  1. Johanna Says:

    You offered me plain old iron, a cubic meter of it. I would have accepted the meteorite, and then sold it and retired and not worried about heating my house because I’d be too busy adventuring. Also, I declined on the grounds that I do not keep my house at a constant temperature and that heat costs the same at 2 a.m. as it does at 2 p.m. under my current setup. Given that I heat “on demand” (i.e. when I want the heat), it is a lot quicker to heat the air, and there is no point having the iron block release heat while I’m not there.

  2. Marlene Says:

    Ok. What I really wanted to say, but didn’t want to sound radical, is that you should cut a perfectly fridge-shaped hole in the wall between your kitchen and the room next to it. Wedge the fridge in there, and you can have the heating effect of the fridge in the kitchen, and not lose any of your kitchen heat into the fridge whenever you open it to get your desired cold food. Since it’s next door, it won’t be that far from the kitchen, and presumably, the room next door is still warmer than outside. If this scenario puts your kitchen in the other (heated) neighbour’s half of the house, you get even more fridge by-product heat (as fridge will work harder), and she gets free beer.

  3. Turboglacier Says:

    Wow… Marlene, you’re as brilliant as your sister. I will get my Sawzall out and begin destruction immediately!

  4. MB Says:

    So, why don’t refrigerators have a vent that can be switched to vent waste heat outdoors in summer, and indoors in winter. In fact, why doesn’t my fridge use cold from the outdoors in winter, saving all the fuss of creating cold?

  5. bv Says:

    Why is it called cold house if so much is about heating? When I had kids at home I heated. Now that it is just me, I can’t see spending the money on myself it takes to stay comfortable. I have some heat in the bathroom and under the sink in the kitchen to keep my Massachusetts home’s pipes from freezing. Otherwise, the third winter without heat. I sleep with an electric blanket and several additional layers to trap that heat and sometimes I’d plant my feet on an electric heater made specifically for that, but this winter I’ve been able to get by on The North Face tent booties. I wear glove/mittens with exposed fingers that have a pullback mitten cover. The water heater is solar/electric and runs year round. I think about going tankless. My problem though is one you have a reference link to. In the summer I can keep food frozen in my fridge/freezer but in the winter I have to give up on regulated refrigeration because it just stops working when the temp drops. No issue of where to set the device, heated room vs. cold room, as the whole house is cold. So, what I’m looking for any device, it doesn’t have to have a refrigerator, it could just be a freezer as the house is refrigerator enough by itself, but a device that will continue to function reliably and keep stuff frozen, even if everything outside it is already about that same temp. Anything like that that you know of? I get tired of eating canned foods in winter but have little choice if it’s stuff I want to be able to keep around without spoiling.

    • coldhousejournal Says:

      “Why is it called cold house if so much is about heating?”

      Ha! Good question Brian. It’s called “cold house” because, when I started this blog, I was keeping my house colder than anyone I knew personally. Since then we’ve gotten colder still– yet, in the process, and through the magic of the Web, we’ve also flushed out a bunch of people like you who are even colder. I salute your accomplishments! As I’ve had to admit several times lately, some of the people we’ve “met” through this process really make us look like wusses– even as most of our friends still think we are extremists.

      As for your question about a food storage device, I’m still a bit confused. Are you looking for something that will just keep stuff frozen? Or something that will keep things fridge-temp, even if the surrounding room becomes freezer-temp? (i.e., something capable of both warming and cooling itself, depending?)

  6. bv Says:

    I’m not down on heat either myself. It’s just that now, when I’m the only one living in this house, I can’t see heating any part of it above what will keep my alive or avoids damage to pipes and appliances. That wasn’t so when we were a family and I had my kids running everywhere. Then the indoor environment had to be conducive to any an all activity and had to sustain them healthily so then it was always fully heated in the winter. Heat though was a chore. The house was built electric then wood stoves were added years later. Using the electricity is prohibitive so it never got turned on. All the years with my kids it was wood heat but with wood, you’re a living component of the heating system and also a fallible one. You have to get up in the middle of the night on coldest days to feed the system. If you don’t stay on top of things the system can get to hot or drop to low and become hard and slow to rebuild. And cleanup, a never ending chore, and one that you have to try and schedule so that there is no major heat lapse, hard because you have to let the system idle down cold enough to the touch to do that cleaning and while approaching that handleable condition the system gives little heat or comfort.

    It just gets tiring and as cheap as it was compared to electric (not so cheap when you consider all the tending that must be done or the possible damage that can occur if the system ran rampant) I get to lazy and to frugal and just don’t want to spend any money or put any more time into it, thus the no heat or this mostly no heat solution.

    To clarify on refrigeration, what I’m looking for is something that will keep frozen food frozen. My house is already a refrigerator in the winter, though that temp isn’t well regulated. I just wish I had a small area, maybe two cubic feet or so, where I knew everything I put there would stay frozen, regardless of the temp in the rest of the room.

    A freezer that still freezes when everything around it is already frozen or nearly so.

  7. coldhousejournal Says:

    Hm. So is it the case that normal freezers won’t operate well, if the room temps are already close-to-freezing? Not something I’ve ever looked into, so I have no idea. But if that’s so, I don’t have any ready suggestions… unless maybe a well-insulated cooler/icebox with a chunk of dry ice in it!

  8. bv Says:

    That might work, but I’m thinking more in terms of something that is self regulating. I did have two thoughts on that after following your link. One, that I could put an enclosure around the bottom and back of a freezer or refrigerator/freezer and install a small heater in that. That seemed counterintuitive though, as such units already produce their own heat in those areas and to do that, heat them further, seemed like something that would drive down their efficiency, but that got me thinking again. Why not just build the enclosure then add nothing to it. Maybe capturing some of the exhaust heat from the appliance and holding it there is all that’s required. Sounds rather New Englandy too. Like the school buses we see with the jacketed hoods in winter.

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