冬暖かく夏涼しい住宅をつくる方法vol.2

夏の暑さは嫌いな方ではなくて、汗かきなのですが、わざと暑い日中に散歩をしたりします。季節の匂いみたいなものが好きで、特に季節の変わり目には敏感になるのか、今なら冬の匂いですかね、どういう匂いかを言葉で説明するのは難しいのですが、枯れ草のような、夜になると冷たい空気の乾いた匂いというか、感覚的で上手く説明できないですが、夏も季節の匂いを嗅ぎに外へ出ます。

ただ、今年の夏だけは違って、外へ出ることに身の危険を感じましたね。暑過ぎて外出を止めよう、陽が落ちてから出かけようと、はじめて思いました。ちょっと外に出ただけで熱中症になりそうで、水分を取っても追いつかず、身体がどんどん熱くなって沸騰してくる感じ、その状態が一番危ないらしいです。

だから、今年の夏は屋内にいることが多かった、常にエアコンがかかった部屋の中。電気代も結構かかりました。ただ、エアコンをかけないと室内にいても熱中症になりますから仕方がないですが、エアコンの風があまり好きではないので、寝る時には苦労しました。

そもそも、外の気温が高くても、室内の温度が上がらなければエアコンをかける必要は無いですよね。エアコンをかけなければ電気代が安くて済みますが、エアコンをかけないで済むということは、それだけ室内が快適だということ。春や秋の中間期は冷暖房をかけずに過ごせて気持ちいいですよね、夏にそこまでの快適性を得られなくても、エアコンをかけずに過ごせたら、その快適性に近づきますよね。

住宅の断熱性能は冬を基準に決めます。冬の目標室温を達成するために必要な断熱性能が数値で厳密に決まります。ただ、ここで問題になるのは、冬を基準に決めた断熱性能だと、夏はより暑くなるということ。

冬は外の寒さが室内に伝わらないように高い断熱性能が要求されます。いわゆる高断熱ですね。そこに隙間風などか入って寒くならないように気密性の高さも必要となります。高気密高断熱、それを行うことは難しくないです。

魔法瓶を思い浮かべ下さい。それがまさに高気密高断熱の家です。中に熱い飲み物を入れれば1日中熱い、冷めない。冬は一度暖まれば、その暖かさが持続して、1日中暖かい、だから、暖房器具をずっとつけておく必要が無いので光熱費も安くて済む。

中に冷たい飲み物を入れても1日中冷たい、氷も溶けない。だから、夏もエアコンで室内を冷やせば、1日中冷えている、だから高気密高断熱がいいと思いますよね、ところがです、魔法瓶と実際の家は違うのです。

実際の家はそれでも外の熱が室内に入ってくる、窓から、太陽の日差しが。あと生活熱というのもあります、キッチンのコンロなど。あと人も発熱しています。冬夏関係無しに、暖房も冷房もかけなくても、高気密高断熱であっても無くても、日中の室温は放っておいても上がります。

それでも冬はいいです、暖かくなるのだから。問題は夏です。何もしないで放っておくと日中はどんどん室温が上がります。大体午後になると外気温より高くなる。そして、その熱は高気密高断熱の家だと外に逃げないので、よりどんどん室温が上がることになる。これを先程も例えましたが「魔法瓶効果」と言います。

室温がより上がるのを冷房で冷やし続ける。高気密高断熱の家にしてしまうと、夏の冷房負荷が大きくなり、光熱費が余計にかかります。

ではどうすれば良いのか？

高気密高断熱にしないことです。ただし、そうするためには冬の対策が不可欠です。もちろん、夏だってそれだけでは快適に暮らせません。

冬と夏の両方を快適に暮らすためには、自然の力を利用しないといけません。その話は、ここまで長くなりましたので、また次回に。

"How to make a warm summer cool house in winter vol.2"

I do not dislike the heat of summer, I am sweating, but I will walk for a while on purpose on purpose. I like something like the seasonal smell, especially whether it becomes sensitive to the change of the season, now it is a smell of winter, it is difficult to explain what kind of smell it is, but like a dead grass, at night I can not explain it sensibly well that it is a dry smell of cold air, but in the summer I will go out to sniff the season's smell.

However, unlike the summer of this year, I felt the danger of getting outside. Let's stop going out because it was too hot, I thought for the first time to go out after the sun went down. It seems to become a heat stroke just by going out for a moment, feeling that the body gets hotter and steams more quickly, taking that moisture, it seems that the condition is the most dangerous.

So, this summer I often stay indoors, in the room where air conditioning always took place. Electricity bills took quite a while. However, there is no choice because it will be a heat stroke even if you are indoors in the room, but you do not like the air conditioner's wind so much, so it was a hard time to sleep.

In the first place, even if the outside temperature is high, you do not have to turn on the air conditioner unless the room temperature rises. If you do not apply air-conditioner it will cost less electricity, but not having to wear air-conditioner means that the interior is comfortable as much. It is comfortable to spend the mid-season of spring and autumn without putting on air-conditioning and heating, even if you can not get the comfort that much in summer, if you can spend without air conditioning, you will be comfortable with that comfort.

The insulation performance of the house is decided on the basis of winter. Winter goal The adiabatic performance necessary to achieve room temperature is strictly determined by numerical value. However, the problem here is that if the insulation performance decided on the basis of winter, the summer will get hotter.

In winter, high insulation performance is required so that outside coldness will not be transmitted indoors. It is so-called high insulation. A high level of airtightness is also required so that there will be no draft winds entering there and getting cold. High airtight high insulation, it is not difficult to do.

Please think of a thermos bottle. That is exactly a high airtight, highly insulated house. If you put hot beverages inside, it will be hot, not cool all day. Once it warms up in winter, its warmth continues, it is warm all day, so you do not need to keep the heating equipment all the time, so the utility costs are cheap.

Even if you put a cold drink in it is cold all day, ice will not melt. So, if you cool the interior with an air conditioner in the summer, it is cold all day, so I think that a high airtight high insulation is good, but it is, the thermos bottle and the actual house are different.

Actually, the outside still enters the room, the outside sunlight from the window. Another thing is life heat, kitchen stoves and so on. People also have a fever. Even if you do not need heating or cooling without winter or summer relationship, even if it is highly airtight and highly insulated, room temperature will rise even during the day.

Still winter is nice, it will be warm. The problem is summer. If you do not do anything, the room temperature rises steadily during the day. It gets higher than the outside temperature in the afternoon. And since that heat does not escape outside if it is a high airtight, highly insulated house, the room temperature rises more and more. As I mentioned earlier, we call it "Thermos bottle effect".

Continue to cool down the room temperature rises in the air conditioning. If it becomes a high airtight and highly insulated house, the cooling load of the summer becomes large, and the utility cost increases unnecessarily.

So what should I do?

It is not to be highly airtight and highly insulated. However, in winter measures are indispensable to do so. Of course, summer alone can not live comfortably alone.

In order to live comfortably in both winter and summer, we must use the power of nature. That story has been long so far, so next time.