[tsakach]

$this->bbcode_second_pass_quote('gg3', 'R')e. the Coleman unit:
192 watt/hours per day = 70.08 KWH/year. That's pretty good if the main goal is to reduce absolute power consumption, for example in an off-grid situation where every watt saved is a major savings in cost of PV panels.

[dooberheim]

tsakach, what is the capacity of the Coleman unit in Btu/hr or an equivalent measure? I'd be curious how large (or well insulated) of a freezer could be serviced by something like that, and how much thermal mass one would need to incorporate in the larger freezer to avoid large temperature fluctuations with a relatively empty compartment.

DK

[oowolf]

I bought a used 12v RV "fridge/freezer" for 35$, It's only about 2 cubic feet--but I use it only for freezing meat--It will hold around 80 pounds--tightly packed. I have it "buried" under the floor of my cabin, where the ground stays cool all summer. I put 4 inches extra styrofoam around it but left an air gap to vent heat. I believe it draws like 130 watts, and I doubt it runs even an hour a day in summer--once the meat has cooled. It runs directly off the panels (I have 8 65 w Solarex); no need for a battery or even controller.

I have a springbox for cooling produce, milk, etc. It runs around 46-48 deg. Not great, but enough to keep milk 3 to 4 days.

[tsakach]

$this->bbcode_second_pass_quote('dooberheim', 't')sakach, what is the capacity of the Coleman unit in Btu/hr or an equivalent measure? I'd be curious how large (or well insulated) of a freezer could be serviced by something like that, and how much thermal mass one would need to incorporate in the larger freezer to avoid large temperature fluctuations with a relatively empty compartment.

[gg3]

Looks like oowolf scores a victory in the "cold war":-)

47.45 KWH/year.

That works for any case where you can do custom design & implementation. What I'm trying to achieve is something that works as an off-the-shelf product. These are two entirely different sets of needs, but the former certainly informs the latter.

Re. using the Coleman unit to cool a larger container: Probably won't work, and will run the Sterling constantly to the point where it fails early. I wouldn't suggest it. The Coleman unit is already a good off-the-shelf solution where someone can limit their refrigeration needs to a few key items.

[ChumpusRex2]

$this->bbcode_second_pass_quote('gg3', '
')What's the make & model number of your unit? Is it a combined fridge/freezer? If so, what's the capacity of the freezer section?

Your figures add up to about 146 KWH/year. That's damn good. How are you taking your measurements?

[tsakach]

$this->bbcode_second_pass_quote('gg3', 'R')e. using the Coleman unit to cool a larger container: Probably won't work, and will run the Sterling constantly to the point where it fails early.

[dooberheim]

$this->bbcode_second_pass_quote('tsakach', '')$this->bbcode_second_pass_quote('dooberheim', 't')sakach, what is the capacity of the Coleman unit in Btu/hr or an equivalent measure? I'd be curious how large (or well insulated) of a freezer could be serviced by something like that, and how much thermal mass one would need to incorporate in the larger freezer to avoid large temperature fluctuations with a relatively empty compartment.

[dauterman]

Hi,

I have been looking for a new washing machine and spent a long time on the internet searching for efficiency numbers. The best site for finding efficiency info is the Energy Star site. ENERGY STAR is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy so I figure their numbers are half-way reliable :):) or at least they are not trying to push one particular product. Their site:

http://www.energystar.gov/index.cfm?fus ... ducts_html

The explanation for all these numbers can be found at:

http://www.energystar.gov/index.cfm?c=c ... es_washers

Energy Factor

Energy Factor is a metric that was previously used to compare relative efficiencies of clothes washers. The higher the Energy Factor is, the more efficient the clothes washer is. For clothes washers, Energy Factor is calculated using the following formula:

Energy Factor = 392 x Volume (ft³)/Annual Energy Usage (kWh)

The Modified Energy Factor (MEF) measures the energy used during the washing process, including machine energy, water heating energy, and dryer energy. The higher the MEF, the more efficient the clothes washer is.

Water Factor - The Water Factor is a the number of gallons per cycle per cubic foot that the clothes washer uses. The lower the water factor, the more efficient the washer is. So, if a clothes washer uses 30 gallons per cycle and has a tub volume of 3.0 cubic feet, then the water factor is 10.0.

Currently, all ENERGY STAR qualified clothes washers must have a minimum MEF of 1.72 and a water factor of 8.0.

***************************************

So I went wading through the numbers. It look like the efficient washing machines can be grouped into two groups:

GROUP 1 - These have low tub volume and low KWH/Yr, but ther energy efficiency is only in the 60% range. Examples:

Bosch WFL2090UC Axxis 1.85 121 2.03 1.26 61%
Crosley CFW2000F 2.65 126 1.97 1.26 57%
Frigidaire FTF530F 2.65 126 1.97 1.26 57%
General Electric WBVH5100H 3.11 120 2.09 1.26 66%
Miele W1113 Touchtronic Series 1.73 113 2.11 1.26 67%

GROUP 2 - These have larger tub volumes, use more KWH/Yr, but have a much higher efficiency, sometimes in excess of 100%. Examples:

Siemens WFXD5201UC 3.31 182 2.57 1.26 104%
Whirlpool LHW0050** 2.46 212 2.79 1.26 121%

My first thought when I saw this is that it is impossible for a washer to have greater than 100% efficiency (i.e. it is against the second law of thermodynamics) and that the numbers must be off.

On looking over the info more, it seems that the overall efficicency numbers are based on both the washing and drying. Drying is much more energy intensive due to the large latent heat of evaporation of water. So the way the GROUP 2 washers work is to spin the closes so hard in the final spin cycle (usually going at 1200 RPM) that the clothes come out of the washer much more dry than a GROUP 1 washer (these only spin at about 800 to 1000 RPM and don't get out as much water from the clothes).

So the GROUP 2 washers take more KWH/Yr in the wash phase, but if you are using a clothes dryer (as opposed to hanging the clothes on a clothesline) you will save more energy in the drying phase than is used to spin the clothes in the washer. Remember that the energy used to mechanically remove water from clothes is much less than the latent heat of evaporation of water.

Just my 2 cents worth.
dauterman

[SolarDave]

$this->bbcode_second_pass_quote('gg3', '
')What I'd like to see here, are results from other folks using a Kill-A-Watt meter to measure the power consumption of their own washers (and other appliances), and specifying the settings they are using (e.g. wash cycle options).

[gg3]

Good stuff, SolarDave. 140 watt-hours, or 0.14 KWH per load. Question is, how many pounds of dry clothes went into that load? I'm going to guess about 8 lbs, which would be about 0.02 KWH/lb., which is quite good. (My twin tub washer uses about 0.01 KWH/lb., and you can't get any lower than that except to use all hand power.)

Now the guy in the article discusses a hypothetical pedal powered dryer, but that's not quite the right approach to take. Start with a hand-cranked wringer and a clothes line. When it's raining, use an indoor clothes line. Tumbling the load just causes premature wear on fabrics anyway (the lint in the dryer).

Another possible approach is to use pedal power for the wash portion of the cycle, a hand-cranked wringer to get the suds out between wash and rinse, and electricity to power a highspeed final spin in a separate spin-dryer (see also Spin-X for an example).

One last item: 20 minutes of soak before the agitation starts, considerably reduces the amount of agitation needed.

---

The truly difficult item to solve isn't laundry, but cooking: how to produce all that heat in a controlled manner without gobbling up every available piece of wood as fuel. Solar ovens are part of the solution, but what is also needed is an indoor replacement for the stove burner.

[dauterman]

Hi,

I found another list of the most efficienct washing machines. This one is from The American Council for an Energy-Efficient Economy:

http://www.aceee.org/consumerguide/clotheswashers.pdf

This is from 2005 and they plan to update it in Fall, 2007 to include newer models. As of the 2005 issue of this report they list the most energy and water efficient washers in descending order as:

Whirlpool LHW0050
Eurotech EWF272EL
Asko W6461

[Curator]

$this->bbcode_second_pass_quote('gg3', 'A')nother possible approach is to use pedal power for the wash portion of the cycle, a hand-cranked wringer to get the suds out between wash and rinse, and electricity to power a highspeed final spin in a separate spin-dryer (see also Spin-X for an example).

[tambayo]

$this->bbcode_second_pass_quote('Pops', '')$this->bbcode_second_pass_quote('gg3', 'D')etergent left in clothes: classic symptom of using too much detergent. With front loaders, you use *much less* detergent than with top loaders.

[mistel]

I saw this

http://mtbest.net/chest_fridge.pdf

and thought I had to make one. It is a super efficient fridge that is made out of a chest freezer. I am slowly easing my wife into the idea. I bought a "kill a watt" so I can show how inefficient our current new fridge is.

The article says it best, but it really bothers me how poorly designed current fridges are, even Sunfrost fridges, that supposedly are energy efficient fridges.

Yes, I will have to move a few cabinets around and it will look ugly, but I think it will be worth it.

Peter

[frankthetank]

This has been discussed before here and on other forums. Its a sweet setup. I would be doing this right now, but my wife doesn't like going into the basement for food! (thats where i have a chest freezer). You can buy one of the smaller Haier freezers for around 100bucks and modify away. Very cheap to run. We have a very efficient refrigerator (new) and it still runs all the time in this midwest heat (house temp around 78F).

[Pops]

One of the cheapest was to improve the efficiency of a fridge or freezer is to ad thermal mass. Simply fill up as much unused space as you can with milk jugs or plastic pop bottles full of water.

Every time you open the door of an upright fridge the heavier cold air falls out and the warm moist air that enters needs to be cooled even a chest freezer loses some of the cold air.

Since the ice doesn’t fall out the door the amount of air the jug displaces doesn’t need re-chilling.

I still have plans in my head to increase the insulation of our 2 freezers by first building a rigid insulation board box around them and second building a vent to the condenser to open air. Doesn’t make much sense to take the heat out of the freezer and pump it into the room to be reabsorbed….

In the kitchen remodel I am cutting a vent to the crawlspace in the fridge nook and using a gasket in the opening for the fridge. In the summer the heat will be vented out and in the winter the heat will be vented inside.

[strider3700]

You have to watch some of the new chest freezers don't have external coils so you can't wrap the entire freezer in insulation since they need to expel the heat out of the back. It's a real tick off on my new/old freezer because I'd put it in an insulated box of I had my choice.

[TommyJefferson]

Cool. I'd not see that.

[Pops]

$this->bbcode_second_pass_quote('strider3700', 'Y')ou have to watch some of the new chest freezers don't have external coils so you can't wrap the entire freezer in insulation since they need to expel the heat out of the back. It's a real tick off on my new/old freezer because I'd put it in an insulated box of I had my choice.