[garyp]

Well I did a similar monitoring exercise for my fridge/freezer and got 1.67 kWh per day. That accords with the numbers given here. Give it a good clean, check the seals, and otherwise look for something newer.

[dissident]

The bottom freezer fridges appear to be a step in the right direction. The typical fridge dumps most of the cold air every time you open the door. An obvious improvement is to drop the obsolete door+shelf design and use a drawer configuration. Also, some of the old top freezer models have a continuous leakage of cold air into the main compartment by design (at least that is what it looks like to me).

[WisJim]

A new refrigerator could be lots more efficient than one only 11 years old. Our newest freezer is about that old, and uses (accoding to our Kill-A-Watt meter) about the amount of energy that the original tags said it would. A new equivelant freezer uses about half(accorrding to the energy use tag on the unit in the store). I figure that I could buy a bigger freezer to replace both of my existing chest type freezers and have more space and use less power per year.

We replaced our almost 30 year old 14 cu ft refrig/freezer with a 17 cu ft refrig only unit (we wanted one that was NOT frost free or self-defrosting), and it uses 1/3 to 1/2 the power of the old one, with more space inside. We don't find it a problem to go to the chest freezer to get a frozen item instead of having a freezer compartment in the refrig.

[bellebouche]

It's euorpean, but for reference a contemporay (A+ rated for energy efficiency) fridge here might use 0.39kWh/day - 141 kWh/yr.


That's for a model with 350 litres volume. Your fridge may be bigger but for it to chow down 2000 kWh/yr is just... insane.

[pea-jay]

Its shocking how much just a decade old fridge will consume. My relatively new one uses 1.5K per day, 1.75K on shopping days.

If you are handy and have your own place, look into converting a new chest freezer into a chest fridge. A guy in australia did that and made a fridge that uses just 10% the electricity of a modern conventional fridge. Makes sense too, any fridge that that opens upward, the cold air stays in.

http://mtbest.net/chest_fridge.html

[dunewalker]

The above suggestions are excellent given a presumed continuation of the 20th century paradigm. However, the transition from an oil-based economy is going to require a powering-down of our expectations of convenience, including food storage and preparation.
On our little off-grid homestead here we make do with a 6 cubic foot RV-type refrigerator, enclosed in a vented pantry to protect it from the warmth of the house, especially during winter. Then we dug a miniature root cellar under the main room floor, where we store foods needing long-term storage, as well as beer even. The main adjustment was to wean ourselves from a lot of refrigerated or frozen foods, like ice cream, which we now only indulge in during trips to town. Transitioning to a mostly vegeterian diet has helped a lot as well.

[rwwff]

I think the 20th century paradigm was about liquid fuels...
The 21st century could be looked at as the true dawn of the electrical era. Granted its just my hunch, but thats why I'm not to interested in trying to be off grid; though a power backup for the freezer is fairly important. Battery+Inverter+Wind or Solar for that purpose seems reasonable.

[oilfreeandhappy]

I'm almost afraid to look at my electricity usage for my refrigerator. It seems like somebody always has it open!

[SolarDave]

$this->bbcode_second_pass_quote('pea-jay', 'I')f you are handy and have your own place, look into converting a new chest freezer into a chest fridge. A guy in australia did that and made a fridge that uses just 10% the electricity of a modern conventional fridge. Makes sense too, any fridge that that opens upward, the cold air stays in.

http://mtbest.net/chest_fridge.html

[gg3]

I've been working on this issue this year, and will have a commercial product available soon (and will buy ad space on this site for it). Until then, here's some of what I found:

Older conventional fridges typically consume 1200 to 1800 KWH/year, sometimes more if they aren't maintained properly or have mechanical problems.

Newer conventional fridges typically consume about 600 KWH/year, which is an obvious improvement.

Small fridges (e.g. "dormitory-size" models) consume nearly as much power as large ones, so an "RV-size" fridge may not be as much of an advantage as it seems.

The best-practice conventional fridge is made by Sanyo, in the range of 8 to 10 cubic feet (apartment size). This is rated at 331 KWH/year, i.e. half the power consumption of your typical large household fridge. The advantage is only partially due to the smaller size; the rest is probably due to insulation, choice of compressor motor, and other design factors.

The "gold standard" is Sun Frost, which claims to use only 110 KWH/year, but costs about $2,500. However, there is apparently some controversy about Sun Frost, and there is a web page that goes into some detail on criticism of Sun Frost's power consumption claims and overall quality of workmanship. In fact, given the cost of Sun Frost, it turns out to have a much higher total cost of ownership than the Sanyo unit mentioned above, even over a 20-year time period with electricity at the relatively high cost of 30-cents/KWH.

The SunDanzer unit is a refrigerator, and does not have a freezer compartment. Presumably you'd buy two units and use them together, in which case power consumption will be proportionally higher (as with our units; see below).

The unit we are planning to produce is also based on the top-loading design, as with the SunDanzer and that Australian guy's home-built unit. We will also be modifying brand-name units for the purpose, and they will run on 120 volts AC rather than on DC (though I suppose we could build a DC version later...). The modifications required for this are neither obvious nor trivial, so it's not something the average person is going to be able to do for themselves.

We anticipate power consumption of about 40 KWH/year for the refrigerator component, and about 120 KWH/year for the freezer component: half the power consumption of the best-practice Sanyo, and not much more than the high-cost Sun Frost, for a retail price (for a full refrigerator/freezer combo) of about half of Sun Frost. (This isn't free advertising; it's not ready for sale yet!:-)

Meanwhile, if you want to improve efficiency of a conventional fridge:

Keep the radiator coils clean. Vacuum them regularly, dust acts as an insulator and seriously reduces efficiency. On the other hand, your vacuum may use from 800 to 1200 watts, so perhaps the thing to do is dust them with a feather duster and then wipe them with a sponge dampened with some mildly soapy water.

Assure adequate air circulation around the coils. Minimum 6" clearance to the wall behind the fridge; ideally allow 12". If you can't do that, a computer fan and a piece of flexible dryer duct can at least get more air back there, and can be worth about a 10% improvement in efficiency.

Keep the seals clean. Dust and dirt can build up on the door seal and the area it seals to. Wipe this down regularly with a damp sponge using mildly soapy water. Best to do it whenever you're defrosting, since you'll have the doors open and the unit unplugged during those times anyway.

Frost-free models consume a lot more power than the conventional types that you have to defrost.

If you have empty space in the fridge, fill it up with bottles of water (e.g. empty milk, juice, or soda bottles, washed thoroughly and then refilled with tap water). These will provide thermal mass and minimize the amount of air in the cabinet. Cold air sloshing onto the floor whenever you open the door, costs about half of your energy consumption for a fridge, so replacing the air with something that doesn't slosh onto the floor (e.g. bottles of water) will always help.

For the freezer, fill up the empty space with those blue ice-packs. These are designed to deal with the expansion/contraction issues, i.e. compared to bottles of water. But if you must use bottles of water, fill them no more than 2/3 full, squeeze them slightly to get rid of excess air before screwing the lids on, and lay them down on their sides. The water will expand as it freezes, and the extra space in the bottle is needed to allow room for this, otherwise the bottle will burst. (In fact the expansion itself does not require all of that extra space; but when the water is partially frozen, the extra space is needed for chunks of ice to move freely, otherwise they might jam up a smaller area and the bottle might still split open.)

Re. the 21st century & powerdown: Food refrigeration is not only a matter of convenience, but also of preventing potentially fatal disease from improperly stored food. If you want to get away from refrigeration altogether, you need to do all the upstream & downstream items about modifying your diet so you do not need to keep perishable items on hand long enough to spoil, and also so you do not need to store leftovers. This can be particularly difficult with regard to meat and dairy products.

Tribal hunter/gatherer cultures typically used up the majority of meat from a hunt at one time by sharing it among many families, and then smoking or drying the rest as a means of preserving it for storage. This is completely outside my area of competence, though another member of our community planning group (Itch, on this site) has been doing serious research in this area including hands-on experimentation.

Another solution for intentional communities is to have central refrigeration for perishables, in a community kitchen with adjacent dining room. Private homes would not have refrigerators of their own, and individuals would go to the communal dining hall for most meals particularly where perishables were involved. The large central refrigeration can be built using commercial-grade components and a super-insulated room or large closet. Overt power consumption for this would appear high, but in fact is considerably lower than the combined total if each household had its own fridge.

[pea-jay]

It occured to me GG, that a combination chest fridge (only) for household use and a community deep freezer may offer the best bang for the energy buck interms of consumption AND convenience. Which component do most households rely on? The fridge. Which one lends itself better to communal use: the freezer. With a little planning ahead, a household member could walk over to the main freezer, collect the foods for that nights dinner and or deposit excess food for long term storage.

Just a thought.

[Concerned]

$this->bbcode_second_pass_quote('DoctorDoom', 'I') am still on the hunt for how my modest home could possibly be gulping 10kwh / day of juice, and I think I've found the primary culprit - my fridge. According to the kill-a-watt meter it's gulping down over half my daily draw, totalling 2000 kwh / year. That seems like a lot but I don't really know. The fridge isn't really that old (maybe 11 years?). Anyone got any figures I could compare with and/or recommendations for a replacement?

[SoothSayer]

What a pleasant thread!

No flames, no racism, no pointless posturing.

[skeptic]

$this->bbcode_second_pass_quote('DoctorDoom', 'I') am still on the hunt for how my modest home could possibly be gulping 10kwh / day of juice, and I think I've found the primary culprit - my fridge. According to the kill-a-watt meter it's gulping down over half my daily draw, totalling 2000 kwh / year. That seems like a lot but I don't really know. The fridge isn't really that old (maybe 11 years?). Anyone got any figures I could compare with and/or recommendations for a replacement?

[killJOY]

One thing I can say:

The SERVEL GAS FRIDGE IS A PIECE OF SHIT. Do not buy one.

This comes from our experience AND the experience of a close friend who had the same model.

This is a small-volume, propane-powered fridge with an ammonia coolant system. It cost $1,500 US dollars at the time of purchase.

After about ten years of use, we began noticing ammonia odors and small blue dots in the ice compartment.

This worsened, until one day it just stopped running.

Within a year, our friend's fridge did the SAME THING.

It took over a year to find someone who could repair it. The operation is a 3 hour drive from here. Needless to say, we didn't get around to hauling the fridges there for a long time.

In the meantime, we fired up a 1930s model Servel kerosene fridge that someone had given us. It has spent most of its life on an island off the coast of Maine. Mrs Tarbox, the original owner, (Not who we got it from) kept meticulous notes on how to care for it.

It has an old fashioned pot burner and a two gallon tank. You have to clean the wick about monthly. We run it only from May through October, at which time we don't run a fridge because there's PLENTY of cold air in Maine to use. I'm constantly telling people: Why the hell do you pay to cool food in the winter months when all you have to do is put the food in an unheated hallway or a pantry with the door closed?

So anyway...two weeks ago we FINALLY loaded up the newer Servel pieces of shit on our friend's truck, and he took them for there little ride to the repair shop.

Verdict: bad regulator, bad this, bad that. Will cost $600 to repair.

They still have the fridges. We don't need geranium containers here.

So, once again: For those of you tempted to get a non-electric Servel fridge: DON'T DO IT.

Unless you want to find a 1930s kerosene model somewhere....

[Kingcoal]

As a rule of thumb when buying appliances, look for the [url=EnergyStar]http://www.energystar.gov/[/url] badge.
If you have a tank style electric water heater, that is probably about half of your electric bill right there. Tankless water heaters are far more efficient. If you live in the south, then most of your electric bill is probably going into air conditioning. The moral of this story is to look at everything, not just the evil frig.

[sysfce2]

$this->bbcode_second_pass_quote('dissident', 'T')he bottom freezer fridges appear to be a step in the right direction. The typical fridge dumps most of the cold air every time you open the door. An obvious improvement is to drop the obsolete door+shelf design and use a drawer configuration. Also, some of the old top freezer models have a continuous leakage of cold air into the main compartment by design (at least that is what it looks like to me).

[gg3]

Pea-jay: Re. households having super-efficient fridges, and a community kitchen having one central freezer: Excellent idea! That one's a keeper for sure. I can live with walking to the community kitchen when I'm itching for an ice cream fix, and/or possibly building a "micro freezer" that's capable of storing maybe one cubic foot of stuff (e.g. ice cream) at a time.

In fact, in this context, "micro freezers" might be viable at minimal energy consumption. Think of a large box that's super-insulated and has a very small storage compartment. Enough for two trays of ice cubes and three or so half-gallons of ice cream. Hmm...! There's my next R&D project:-) (Maybe the otherwise terribly-inefficient Peltier junnction coolers would even be viable in this application, if only because the space to be cooled is small and there wouldn't be a viable compressor system on that scale..? Hmmm.. I think I'm going to do this one ASAP just to see what happens...)

---

Kingcoal, re. Energy Star:

Useful when looking for major brands, but smaller companies may not be able to handle all the paperwork and overhead cost of getting the rating.

As well, the ratings are based on certain types of designs and may not even be available for other designs. For example I have a twin-tub washer that's probably the most electrically-efficient washer on the market today (measured as little as .01 KWH per pound of laundry, i.e. .05 KWH for a 5# load), but it's not in the Energy Star ratings because the design isn't covered by the regular categories. So, what would EnergyStar do with a top-loading refrigerator...?

And, the ratings are based on assumptions that may not hold for individual cases. For example the washer ratings are "per year" rather than the more useful "per load of X pounds." How many loads do they expect people to wash per year, eh? And then you have variations for hot water heating methods, e.g. solar thermal will lower the grid power consumption across the board.

What we expect to do when we start selling our high-efficiency fridges & freezers, is to conduct a series of empirical tests, measure the power consumption, and post our methods and results on our web site in order to back up our claims. For example, "one week with the room at W ambient temperature, and the fridge/freezer at X inside temperature, with Y food items stored, and with the door opened Z times per day."

We'll control for each of those variables: ambient temp in the room, temp set on the fridge and freezer, quantity and types of items stored in each unit, and number of times per day the door is opened. We'll also run tests using standardized plastic containers filled with standardized quantities of water, intending to determine how long it takes to get the water down to the cabinet temp and how much power it takes to do so (compared to power used when running with contents already at the target temp).

All of those data will be presented in a manner that enables reasonable comparisons to EenrgyStar-based ratings. For example, if we find we use 3KWH in a week, under WXYZ conditions, we can reasonably extrapolate that to a year and claim 156 KWH/year.

And since the methodologies will be published, any buyer or any independent lab will be able to verify them.

[WisJim]

$this->bbcode_second_pass_quote('killJOY', 'O')ne thing I can say:
The SERVEL GAS FRIDGE IS A PIECE OF SHIT. Do not buy one.
This comes from our experience AND the experience of a close friend who had the same model.
In the meantime, we fired up a 1930s model Servel kerosene fridge that someone had given us. It has spent most of its life on an island off the coast of Maine. Mrs Tarbox, the original owner, (Not who we got it from) kept meticulous notes on how to care for it.
So, once again: For those of you tempted to get a non-electric Servel fridge: DON'T DO IT.
Unless you want to find a 1930s kerosene model somewhere....

[WisJim]

Another point: many new refrigerators do not have the "radiator" coils on the back, but instead they are bult into the outer skin of the refrigerator, so you can't clean them, but must make sure there is free space for air movement around the sides of the refrigerator cabinet. Same is true for many freezers, chest or upright.

Our less-than-one-year-old 17 cu ft refrigerator only upright unit has been using about .35 to .4 kw-hrs a day in the last week, with daily temps in the low 90s, and I had been home, getting cold tea out of the fridge regularly all day. So it is using around 120 kwhrs/yr at that rate.