Monday, October 20, 2008

JJNN Monday: Science - 11

Welcome again to JJNN for Monday October 20th, 2008. Today we will be talking about something that will help me get though the winter.

I know know if it is getting cold where you guys are, but I can tell you that in the morning at night here it is really getting cold where I am. It has gotten to the point where I want to get out my heaters and turn them up to high. I say "heaters" because Japan does not believe in central heating. I always joke with my friends saying that the warmest room in my house during the middle of the winter is my refrigerator. That means that there are only so many ways to survive the winter in a old drafty house like mine. The first way so to drag out a lot of heaters and turn them all up onto high. Another way to survive the winter is to spend the whole winter under a kotatsu. A kotatsu is a table with a blanket around its edges and a heater on the bottom. You can see a picture of a kotatsu below.

I love kotatsu, but once you sit under a kotatsu, you never want to leave. I have spent many a lazy winter weekend not leaving the house because I was comfortable sitting under the kotatsu. I have even spent many a night sleeping under the kotatsu as well. A lot of Japanese people say that you will catch a cold if you sleep under a kotatsu, but I have never gotten a cold because of that.

Another thing that helps people in Japan get though the winter is Japan is called a kairo. Kairo are little bags of chemicals that suck in oxygen and go though a chemical reaction that releases heat. The actual chemical reaction is

Fe + (3/4)O2 + (3/2)H2O -> Fe(OH)3 + 96 Kcal/mol

In other words powdered iron reacts with oxygen from the area and water vapor that is also in the area and produces Ferric (III) Iron Hydroxide (AKA rust) and some energy. This energy is in the form of heat and it makes everyone happy on a cold winter night.

The only problem with these kairo is the fact that they only last for so long. Sure the reaction could last up to eight hours depending on the amount of iron powder in the kairo. After the reaction is done with there is no way to change the rust back into iron, so the kairo has to be thrown away. These things were made to be disposable, but that is not very environmentally friendly, is it?

That is where Sanyo Electronics comes in. Sanyo wanted to find a way to get just as much heat, but also be more environmentally friendly. They ended up coming up with a new type of electric kairo called the eneloop kairo. Eneloop stands for Energy Loop. You can see the kairo below.

It looks sort of like a mouse, doesn't it? The eneloop kairo uses two rechargeable double A batteries. It can be used up to 5 hours on 4 and a half hours of charging. It is also said that it can be charged up to 1000 times without having to change the batteries at all. When the batteries do finally fail, they just need to be switched out and the kairo can be used again. This thing will definitely help me though the winter.

As with all things, there is a down side. The first downside I can see is the wait. With the traditional kairo, when one runs out all you have to do is open another package and you got instant heat, but with this you have to wait for it to change for it to be used again. That means there is a significant wait between uses. The second downside can be seen if you look at the kairo from an ecological point of view. Sure you will no longer be throwing away old kairo (basically rust and a little cloth), but ever 1000 days (3 years of constant use...but who would use a kairo in the summer?) you have to throw away 2 batteries. The batteries contain heavy metals and are very bad for the environment. In the long run I wonder if these things are very ecologically friendly or not.

Any way, it is now time for the word of the day. Today's word is 懐炉(かいろ). It is pronounced kairo and kairo (sometimes translated as "hand warmer" even though it can be used for any part of the body now days). I sort of like the old kairo that you stick to the inside of your shirt. Those keep you warm all day. Some times the kairo react strongly and become really hot.

That's it for today. See you next time at JJNN.

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