Make Your Refrigerator Far More Efficient

There as an article about this on Terrapass. Much of this same debate was debated over there-- except they were a few months ahead of us so they've already dispensed the obvious arguments.

[www.terrapass.com]

Eric Schauberger

@ww2db.com: did you even read the article? or the title of the article?

mahumphrey

Good advice, however I don't know if I would say NEVER use warm/hot water to make ice cubes.

While it will raise the interior temp of the freezer more than cold water, it will also turn the water to ice faster- something that can be convenient in a party situation.

But yeah, if quick ice isn't necessary, cold water is the way to go.

Lactaid Milk = Bachelor(ette) milk. Good for more than a month, just check out the exp dates!

I put bread in the fridge too. Potato-wheat bread lasts the longest.

And store case of beer on bottom...colder and mmmmmm beer!

SigmundTheSeaMonster

I think it must mean to address the condensation & removal of moisture in your fridge and freezer. The evaporation process takes energy from the system leaving it cooler. Regulating that moisture increase would take energy - normally there is a collection system that brings condensed moisture to the back of the fridge next to the warm condenser. There it is used to cool off the hot condensor (by evaporating it into your kitchen, outside the fridge)... and that actually increases the efficiency of your condenser. Who knew fridges had so many thermodynamic processes running concurrently? ( Man that sounded like something off of the Big Bang Theory.)

ShrikumariBabble

@littlemissellie: Thanks, I'll adjust. One problem I have with keeping the freezer too low is that the water line to the water dispenser freezes.

It's okay to store pantry items in the fridge until the space is needed by cold items. I like to store flour, cornmeal. rice, cereal, etc. Boxes and cans can be stacked. It wouldn't hurt to tell someone close to you (or secure a note on the fridge door) why these room temp items are being stored there in case they have to explain at your sudden demise, instead of assuming you were nuts. Don't forget injury ice packs for the freezer. And yes, those green bags do extend the life of the veggies.

SubhadraCatilina

I think the real issue is the energy taken to remove the moisture from the fridge. Air conditioning systems do the same thing; they cool but they also remove moisture from the air, and that takes energy.

JillianGanado

large volumes of liquid (beer/water/etc) help stabilize the temperature of the fridge due to the thermal qualities of water plus thermal mass. water takes way more energy to heat/cool than air, so once the fridge cools the water down, it will help to absorb heat from room temperature stuff you put in the fridge and those bursts of warm air that enter the fridge when you open the door.

also, in the event of power loss, the contents of the fridge will take longer to heat up if the fridge is full.

rather than buy bottled water, get a filtering pitcher or other device to filter tap water and keep it in the fridge. tap water is cheaper than bottled water and produces no plastic bottles.

for travle/convenience a steel bottle is handy, lasts forever, and doesn't leech anything into your filtered water.

and finally, defrost meats and other things in the fridge overnight instead of setting them on the counter. this helps to prevent bacterial growth and the fridge will not work as hard to maintain temperature as the frozen food thaws to the temperature of the fridge.

chrizzle

@PickledEgg: I used to live in a house in England built in the 1830s with 18" thick brick walls. It didn't take a lot to heat, and never needed AC.

Interestingly it had a kind of "thermal mass storage" heater I've never seen in the US. It basically consisted of insulated bricks that are heated electrically during the lowest-cost parts of the day. To release the heat, you open a switch that allows air to be blown across the bricks, warmed, and into the room. The switch could also be on a timer to store heat during the day and release it at night. Of course, it didn't provide the precise thermostatic control that so many of us are now used to...

theczardictates

My freezer is filled with film ...

@akurei77: The Kill-a-watt will cost about $15-$20...and it is useful throughout your household.

cisengineer

@dmccall: I haven't had this problem. The milk always lasts until the expiration date or afterward in the door of my generic fridge. Mayo lasts practically forever. You may want to check your seals.

@jwsamuel: By helping to limit the air circulating, there is less energy spent, since the majority of energy used is spent keeping cold food cold, not cooling down room temperature air. Once something is cold, it take very little energy to keep it that way when compared to actually cooling it down.

Really, the only reason this is relevant is because of the air circulation. In an ideal situation where you put food in, and all energy is spent cooling it and not random amounts of air, there wouldn't be a sizable difference in energy usage between a stocked and near empty freezer. But, I guess we can't always operate under ideal conditions, eh?

Cris 'Shamus' Landefeld

@CalebAesop: Liquid evaporates at any temperature. Ice, if left outside in freezing temps, will actually sublimate and evaporate away. So you are technically incorrect.

The real question is why this is a concern. If evaporation occurs, it typically will cool the surface it evaporates off of. Wouldn't that mean that wet food would cool faster and evaporation helps cool food?

Thud

@earltedly: While that might reduce the amount of air inside the fridge that would be replaced by warm air as the fridge is open, if you want to increase efficiency by stabilizing the temperature, what you want is something with a high thermal mass, like water.

Thud

I fill empty milk cartons with water. They're a good shape for filling space and you have a nice block of ice if you ever need it for a cooler. For double bonus points, a block of ice in a milk carton in your cooler turns into a milk carton full of water in the cooler, not a cooler full of water.

I also pioneered a technique at the office that my colleagues have finally conceded is and was brilliant. We have a tiny freezer that is constantly frosting over (and should get rid of the whole thing) so I've got it almost entirely full of quart cartons of water. Never defrost again.

amandabee

"It is permissible to let hot food cool somewhat before refrigerating it, as long as the cooling period is not long enough to permit bacterial growth. Never use warm or hot water to make ice cubes. Cover moist food, so the refrigerator does not waste energy evaporating the moisture." Evidently not fans of the mpemba effect, then?

KendrickDog

@PickledEgg: Well, this wouldn't likely work with jugs of water, but this is basically just the concept of a thermal mass. That is used in passive solar building design all the time. Have a big earthen mass sitting in front of a south-facing window. The sun heats it all day, and it releases that heat at night. I've been in buildings that maintain a stable ~70-75 degrees years round with zero heating and cooling costs built around this concept.

Quentin Hartman

@PickledEgg: Lol. I'm sure the water would spoil by the time you need it, you'll probably end up kicking it over and shorting your tv/pc/gf/cat

davebm

@AndrewHizer:
Is that a bad thing...? Maybe I should get a new one...

@akurei77: Actually, a P3 Kill-A-Watt meter is $22 (free shipping) on Amazon and a very useful device for measuring instantaneous and time-averaged power used not only for a fridge, but for many electronic devices in the house... cable box, tv, computer to name a few.

www.amazon.com

billz1010

@TownyArt: Cause the result would be "frig" and we know where THAT is going ...

@jwsamuel: I'm no physicist, but I think an additional piece of rationale might be that having a lot of cold items in the fridge will act to supplement the refrigeration. It's like the difference between having an air conditioned room vs. an air conditioned room full of blocks of ice. Of course, I could be totally wrong.

weatherking

@jwsamuel:

A few more ideas... Canned fruit (usually better cold), canned/bottled soda (or beer) (definitely better cold), chocolate (especially good in summer), ingredients that you commonly add to cold foods that you want to keep cold (anything on top of yogurt or ice cream.)

You don't have to stock with perishables.

Another one would be to precook your food for the week and store in individualized servings. That way, you have one big day of cooking and dishes, followed by 6 days of extra time:) We do this, and some meals, we prepare so we only have to lift out the dish and put in the oven, cutting out the prep time and precooking other ingredients (like the pasta, meat, sauce etc for a baked (yummy) pasta dish)

englishman

I've heard the advice before about filling your freezer (and now your refrigerator) with lots of food, ice, etc. to save energy.

While it makes sense that having a lot of ice in your freezer acts as a buffer, two things get in the way of assuming this will save energy:

1. The freezer has to expend energy to freeze all that water into ice in the first place.
2. The freezer has to expend energy to keep the ice from melting.

So even if you save energy by "buffering" the freezer with ice, you still pay to freeze it the first time. And no matter how much insulation you have, some energy must be expended to keep it all frozen.

So wouldn't an empty freezer cost less ultimately? Sure you're paying to keep the air inside cold, but you don't have to freeze anything or work to keep it frozen.

The only way I can imagine a packed freezer running more efficiently is that you displace all the wasted airspace that would have to be kept cold. It makes sort of sense to fill the space with styrofoam I guess; at least you don't waste energy putting it through a phase change (Water->ice). But isn't styrofoam mostly air anyway? So why bother?

Charles Brannon

my freezer is in the basement that is foot numbingly cold, so air going nito the freezer isnt that warm anyway.

jono_

Fridge comes from the brand Fridgidaire

SharanyaKinza

@holyspidoo: Perhaps, but at $150.00, the monitor alone is around 30% the cost of a new fridge (at bestbuy.com). If all you want to do is measure your fridge, that seems like a huge waste of money.

akurei77

@cha0tic:

I would imagine it would be pretty important to close the door slowly (rather than slamming it shut to prevent forcing warm air in would be a good idea too!

I am guilty of doing as you suggest. I also am guilty of not organizing the fridge so I have to hunt for stuff.

englishman

@holyspidoo:

I've used my killawatt to debunk a few of the things I've read recently. So I agree with your sentiment here.

But in this case the physics makes sense and the proposed solution costs nothing to implement. So even if you are right, that it makes "almost" no difference, at least the payback is still immediate and positive. It is also possible that others will get more energy savings than you saw.

Nikkon

I wonder if this same concept can be extended to your house? If I place jugs of water around my house will it help my home's heating and cooling systems to operate more efficiently? This could also serve as emergency water if there was some type of natural disaster, and also help in case of a fire.

@dmccall: I guess that depends on how long it takes you to drink the milk. My family goes through a gallon in a few days, so it's no issue. (The milk is certainly cold enough to drink.) When I was in my dorm room with the mini-fridge, I almost always had to throw milk out because it was bad... I probably should have been keeping it closer to the back.

akurei77

Depending on your current construction, you might be able to put more insulation on the sides and top of your refrigerator. This works especially well with a set in fridge (the additional insulation will be "invisible" being hidden behind the wall.

Also, make sure to have plenty of air flow behind the refrigerator and to clean off/vacuum off any cooling coils located behind or underneath the fridge.

Now if only someone can tell me why "Fridge" is spelled with a "D" and "refrigerator" isn't...

TownyArt

@jwsamuel:

"...minimize the amount of inrushing warm air that has to be cooled when the door opens and shuts"

Nikkon

Placing stryofoam in the refrigerator to fill the "empty" or air-filled spaces will also help. Since air heats up quickly when the door is opened, reducing the amount of air reduces the temp change when opening the door.

ShamimCadkey

@FarrahCallisto: and that way instead of just having the water sit around, on a hot summer day you can pull it out and drink it!

@littlemissellie: we need a preview button! -0.4 F would make more sense on the same line!

littlemissellie

@Hoss: In British restaurants the recommended temperature is -18 celsius, which is -0.4 F

littlemissellie

@dmccall: It actually works ok in mine, because I have a very small fridge. I also don't buy overly large cartons, so they're often empty way before the use-by date.

I had always heard that a full refrigerator uses more energy because there is more surface area to be cooled.

If a fully-stocked refrigerator is more efficient, how does any savings compare with loss do to outdated food that never gets eaten because there is more than is needed in the fridge?

jwsamuel

"Cover moist food, so the refrigerator does not waste energy evaporating the moisture." That does not make sense at all. A fridge cools not warms. liquid ---(evaporation- addition of heat)--> gas

CalebAesop

@dmccall: Ditto mayo.

Although it seems like common sense, alot of people forget or don't think about doing your thinking with the fridge closed. What I mean, is think about what you need in a fridge before you open, open the door quickly, grab your food and close the door as soon as possible. I don't know how many times I've seen my roommates stand in front of the fridge with the door open, thinking about what they're going to get.

i always keep an empty beer case in my freezer. i figure it keeps all of that cold air from spilling out. i do the same in the fridge when i have room.

Before you try ANYTHING with your refrigirator, get a killawatt or a TED (theenergydetective.com).

You'll find out that even your old fridge is not that bad. And even if you change it, it takes about 10+ years to pay for itself. And given new fridges dont last that long anymore, not a good purchase.

As for all these tips... filling the fridge/freezer makes almost no difference... Get an energy monitor, it will make short work of what works and what doesnt.

holyspidoo

DON'T put milk in the door of the refrigerator! (It doesn't stay cold enough to keep it from spoiling.)

dmccall

small article :/

foo

A really effective thing to put in is blocks of polystyrene or any other similar 'missing matter' you get in packaging.

earltedly

or you could have the shitty little apartment fridge and freezer like i have and not be able to keep anything in it.

when i find a really fantastic deal i have to keep it at my mom's house... course she doesn't use her whole freezer anyways, but still.

I hear it's better to keep your fridge and freeze as packed as possible to reduce energy consumption.

Not unless your fridge is being powered by the mold that's growing on the food you let go south...

AndrewHizer

I thought 10 degrees (fahrenheit) was the right temp for a freezer? The article says 5 degrees

Does this mean my refrigerator will be green?

pvtryan2

If you have extra room in the frig, Instead of discarding that plastic milk container, rinse it out with soap and water, then fill it with cold water and put it back in the frig to help stabilize the inside temperature.

FarrahCallisto

In the winter time I always put hot things I'm planning to freeze outside on a mound of snow. Soda, etc, that comes home lukewarm from the grocery store stays in the cold garage overnight rather than going into the fridge. Just don't let it freeze if its really cold.

Obviously this only works at certain times of year, but it's an easy energy saver that shouldn't be overlooked.

@AbsurdHero: I agree. Milk and mayo never have a problem.

@JillianGanado: Isn't dehumidification a byproduct of cooling, not an engineered result? The refrig works by recirculating air over a set of coils that have been cooled. Moist air means condensation on the coils, which then drips off into a tray and runs out. Yes, there is a tiny amount of cooling lost because the effluent water is cold, not room temp. But, the frig isn't spending energy dehumidifying per se.

I still don't understand.

Thud

@TownyArt: yeah, it's a brand thing. in spanish, it's called refrigerador.

I'm surprised people in the US call hamburgers by their name instead of "a Mcdonald".

ridgecity

@Charles Brannon: but what are you going to do with an empty freezer...

Toxsyn

I stopped putting my veggies "out of sight out of mind" to rot in the crisper drawer. They are on shelves now, and the more delicious food that is harder to forget about, such as sandwich fixins and tasty dairy, go in the drawer.

anniekate76

@FarrahCallisto:
Wasn't this in the article?

LetterX

@akurei77: True. But you hardly do it for the fridge alone. The price of the information it gives is priceless. It is paid for inside a year easily.

Helps so much if your electricity works by tiers (X kwh for a day are Y price, then Z price).

Allows to bust myths, tune your habits, and the feedback is in real time, so you know what works. For example, installing a low flow shower head saves me 110$ a year.

It also lets you double check the elec company. Dunno about you, but here in Quebec, they make LOTS of mistakes (always overcharging, never under charging... how odd!)

Very much like the scangauge ([www.scangauge.com]) can help you with fuel consumption. Nothing beats real-time information when energy is concerned, because there are way too many variables to consider.

holyspidoo

@mahumphrey: No, he was too busy coming up with a handle to promote a website to RTFA.

Store your food storage containers (tupperware or glassware) sealed in the fridge instead of cabinets. Bonuses: you keep your fridge full regardless of whether the tupperware is filled with food or not, and you free up cabinet space for other stuff.

@Jeffrey Last:

Yeah, and forces the compressor to run harder and longer.

David Clark

@Swizzler121: This is sound advice. I'm going to try this with icecream pails. I don't throw them out, though I could never think of a use for them. Now I've got one.

paintbox

My wife and I save a LOT of energy by simply not leaving the fridge door standing wide open. Put stuff in it, or take stuff out of it, but then close the door.

I'm always amazed when I see someone on a TV show standing there with the fridge door open, scratching his/her head.

Another thing: In most American homes, the AC/heat is actually the biggest energy user, MUCH more than the refrigerator. Same goes for the hot-water heater and the oven. But the fridge is an easy place to start.

@dmccall: Never had this problem, either. (I've heard about it before, but it doesn't apply on my fridge.) I have a 15-year-old small fridge that came with the apartment.

@PickledEgg: Actually, my physics teacher told me about a house that has pipes running throughout the roof and walls, and the pipes connect to an underground reservoir that cycles the water through the pipes. He said it still needed AC/Heat, but it did reduce the need for it [by like, a few degrees.] Good for late spring/early fall, when it's hot but not like super hot that you need AC.

iSecks

Air conditioning units have the heat exchangers _outside_ ; in the winter, having the fridge dump the heat into the house makes sense. In the summer, a great engineering trick would be to move the waste heat outside somehow. Otherwise the air conditioner has to dump it out --- at a terrible inefficiency. I wish it were possible for this to be feasible.
t

tony3tlh

Filling your fridge with water is bunk. While it's true that you can limit the amount of warm air that rushes in when you open the door, it's way more efficient to fill the space with something with a much lower specific heat than water. Just cooling the water down to begin with will rob you of any energy efficiencies unless you keep it in there, full and cold, never touching it, for quite some time. One benefit, however, would be that your fridge would stay cold a lot longer in case of a power outage.

MaraMaguire

@KendrickDog: Yeah, I was thinking... wait a minute, I thought hot water will freeze faster than cold water....

Jeffrey Last

I keep 2 liter bottles filled with water on the door of the refrigerator and use the Ice gel packs you can get at the dollar store and put them in the door of the freezer and under other items. Just a few, it keeps cold without the condenser cycling, and my light bill is waaay down.

The_Legend

Something to keep in mind while you're stuffing your refrigerator: Refrigerators usually will work most efficiently if air flows through them in the way the engineer who designed the refrigerator expected that it would. This is especially true if you have a side-by-side. The owner's manual for your refrigerator probably has more information about this. If not, or if you don't have the owner's manual, a good rule of thumb is to make sure that any vents have good airflow (don't block them with large items). Also, if you buy replacement shelves, you might want to see if old-fashioned wire shelves are available -- they allow for better airflow than more modern tempered glass shelves.

KirkMetis

I wouldnt go packing your freezer with water containers unless you're planning on leaving them in there for a reasonable length of time. It costs energy to freeze water, so freezing a load of water in an attempt to make your freezer more efficient might end up using MORE energy if you don't leave it in long enough too offset that cost. Also.....defrosting things in your fridge instead of an open kitchen or a microwave is a great way to save energy as during the time the item is defrosting it keeps your fridge cooler so it does less work! ;)

DavinMabus

I used to work in refrigeration at GE: Adding insulation to the walls of the refrigerator is mostly a waste of time: the amount of heat actually lost to the walls is negligible. We evaluated this to make E Star requirements and no dice. An important than you can do is check your door seals for roll ups or other leaks. Especially on the hinge side of the door; the gaskets tend to bend and roll against the cabinet side, creating leaks. Refrigerators actually come from the factory now with a small amount of vaseline on the gaskets to keep this from happening.

IvanMocker

I am ready to believe the NY Times regarding the full refrigerator, but a statement this counterintuitive seems to call for greater explanation.

Imagine two freezers each operating at about zero degrees (F) in a room with an average temperature of 70 (F). The first freezer has 12 ounces of water (or Hungry Man dinners) and the second has 120 ounces of water. How could it be that freezer one consumes fewer watts?
I know very little about these things, but I remember distinctly from high school chemistry that the greater the mass, the more energy that is required to maintain it above or below the ambient temperature.

Obviously, adding density to the fridge will maintain temperature stability (provided adequate air flow is maintained). Perhaps the additional costs of cooling the extra mass is negligible, but how can adding density to a fridge or freezer possibly increase its operating efficiency?

Can we avoid sexist language in Lifehacker posts please? I'm looking at "stuff your handy dad or uncle will tell you."

I find statements like that somewhat discouraging. How many ladies will want to get into condenser coils if they are always presented with the idea that it's a "man's" thing to do?

ionpattern

@dmccall: My milk tends to last well beyond the "expiration" date because I always keep it at the very back of the fridge. I've done this for years and saved a lot of milk as a result. You can also freeze milk if you're going away for a few days so it won't spoil while you're gone.

@Quentin Hartman: Actually there are solar homes that use drums of water as thermal mass, so bottles would work too, but you would need a lot of them.

macrumpton

@Charles Brannon: When you open a freezer (unless it is a top loader) all the heavy dense cold air in the freezer falls out into the kitchen. When you close the freezer door the freezer has to cool the warm kitchen air that moved into the freezer when the cold air fell out. If the freezer is full there is less cold air to fall out and therefore less warm air to need heating when you close the door.

macrumpton

It may not be obvious to everyone, but if you have a choice in the layout of your kitchen, do not put the stove/oven next to the fridge. Also, if you have a crappy looking fridge (like mine) you might consider adding some insulating/decorative panels to the top and sides. A sheet of 1-2" foam with a nice fabric stretched on it or covering the foam with some paneling will add significantly to the efficiency of your fridge. Do not do that if your stove is next to the fridge (fire hazard)!

Another good idea is to check that the seal on the doors of the fridge does not have any gaps. You can check it by sticking dollar between the door and fridge and making sure that there is some resistance to pulling out the dollar. You can get new seals at a hardware store.

Finally, this last idea is a little subtle but still useful. Try to have specific areas in your fridge where you always keep the same products, so you are not rummaging around for several minutes looking for the mustard or hot chili sauce, but know where they are before you even open the door.

macrumpton

@CalebAesop: humidity is raising temperature, and in the process of condensing there is circle of energy losings.

teodorparcel

Remember to clean the radiator bits (usually on the back or underneath the fridge) every few months. Use a vacuum cleaner nozzle to suck away the dust bunnies that grow over the grille that keep the radiator from radiating heat efficiently.

Rowin Andruscavage

surprised no-one has mentioned that the best methods of saving refrigeration energy are 1. turn off that ancient second fridge in the garage if you really don't need it that often, and 2. check and, if needed, replace the door seals, especially on older fridges.

AronneAphareus

@paintbox: So likely to lead to me having tons and tons of old milk cartons full of water sitting in my fridge.

The most important tip is to keep the coils in the back of your fridge clean! Most people never move their fridge, and the back collects large amounts of dust and dirt, clogging up the fan and metal coils. Clean these with a vacuum cleaner to make your fridge more efficient and run less.

RamonaPterelaos

Put the water in the fridge in the winter after leaving it to cool outside. Free cold! Also, don't bother putting eggs in the fridge. They spoil at the same rate room temp or refrigerated. New Nobel prize-winning research of some kind proved it. I forget who/where. Anyways, it'll save you a few door-openings.

VerneyHapiloons

@Thud:

While cooling naturally condenses moisture from air (like dew on a cool morning) there is definitely an engineered process going on so that you don't get dew on your food. Basically you need so many exchanges of air pulled from the food area and run through a condenser that is set at a colder dew point than your fridge. Freezer, too. Remember how old freezers would slowly turn into a big block of ice through frost build-up? Those didn't have engineered humidity control.

Peter_T

That's a great tip, but what about people like me that needs more space in a refrigerator? I presently (and not willingly) have 6 adults living in this house, due to the economy problem, and half of those eat enough for two of them, so it's like having 9 people! One refrigerator just isn't cutting the mustard. I can't even go to the grocery store for a week at a time because there is absolutely NO room.

Does anyone have any tips on what doesn't have to be refrigerated? Like certain salad dressings, vinegars, soy sauce, whatever.

I mean I understand that the safety alarmists want everything refrigerated, but I really need to know what can most likely stay in the pantry.

Anyone?

magnoliasouth