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A 'fridge that uses less power than a lightbulb

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That's really neat, in a why-the-heck-didn't-I-think-of-that way. I wonder if it's a pain to try to organize it, though. Energy efficiency is a wonderful thing, but I really don't want to have to unload the entire thing onto the kitchen floor to find the container of hummus I bought a few days ago.

I'm skeptical. First of all, because the article describes energy consumption in watts (which is like gauging speed in miles). I know, it could be a typo...

Secondly, the 2004 average energy consumption for chest freezers was 344,000 watt-hours per year. (Interestingly, that's an average of 39W, or roughly the same annual energy consumption as that 100W lightbulb if it's lit for 9 hours a day.)

Now admittedly, a chest freezer does keep a wider temperature differential than a chest refrigerator would... but the article claims that his adaptation uses 36.5 kWh a year! That's only 4 watts! It'd be a 90% savings, if true!

But according to Energy Star, chest freezers are only 10 to 15% more efficient than upright freezers. Since according to FEMP, refrigerators use about the same amount of energy as similarly-sized freezers, there's no reason to suspect that an average-sized chest freezer adapted to refrigerator temperatures would run any cheaper than 30W, or in other words 263 kWh per year.

Unless it's being kept in a 40-degree room. *grin*


Edited at 2009-08-17 07:12 pm (UTC)

Re: A fridge too far?

I also tend to be skeptical for the above reasons, plus there already ARE chest fridges - the 12V market (think RVs and solar power) has been all over them for quite some time - Finally, the mechanical engineer in me says the total energy lost by dumping a bunch of cold air pales in comparison to what you need to cool down a single apple. What makes chest freezers (and the fridge versions) so efficient is mostly the amount of insulation that can be packed around them without making them utterly inconvenient since the door does not need to be as insulated as the rest.

Re: A fridge too far?

Huh! Sure, the RV people would be all about chest fridges -- no side-swinging door to fall open if you forgot to dog it down!

Wish my family had had one back in the day. :)

Re: A fridge too far?

The article is not a good one, but the concept is sound and your numbers are more reflective of reality. I know a couple of people who built chest fridges out of chest freezers, because they like reusing old stuff and like saving money. Chest freezers are easy to find, and unlike old fridges, older chest freezers are reasonably efficient. Cost savings ends up being on the order of $5-10/mo.

Since modern fridges don't use a huge amount of electricity (less than a continuously running 100W lightbulb), it's not possible to save a huge amount of electricity by changing them. People tend to overemphasize refrigerators because they are large appliances.

I'm *very* skeptical of this post's claims (is it an "article"? Is it a publication?) Most fridges lose very little energy from air escaping when the door is opened, because air simply doesn't have that much heat content anyway, it's the solids & liquids that take most of the energy to cool, and they take more time to let heat transfer in. A home energy efficiency workshop I attended gave us some results from a study that compared the energy use of a refrigerator that had its door opened far far more often than would ever happen in actual use, vs. one that hardly ever had its door opened, and found the different in energy use insignificant.

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