"I was surprised that it wasn't cold even though I didn't have a rug or anything!!"

"I was surprised that it wasn't cold even though I didn't have a rug or anything!!"
I worked hard at my desk this morning and left the office around 12:XNUMX.
I went to inspect the E residence in Morimachi, Minoh, which is holding an open house over the weekend.
Minoo Morimachi is the coldest place in Osaka, so as of today the water outside is
It was freezing. Apparently it was below freezing last night!!
Just last week, we also handed over the house to Mr. E's sister and her husband.
I also asked about the situation there.
"I didn't need the heating at all during the day. It was almost too hot."
"I just moved in and I don't have a rug or anything, but the flooring isn't cold.
I was surprised!!"
I received the following happy feedback:
The E residence we inspected today also has a living room on the second floor, but it is unheated because of a huge opening facing south.
However, it was quite warm inside and it was impressive to hear the craftsmen saying, "It's easy!"
The only manufacturer that could bring this to a house built by a major housing manufacturer without heating was Ichijo-san.
I think it has to be Sweden.
Also, construction companies that are working hard in the temperature range of Tokyo and Osaka are aiming for now.
Even in a home with a Q value of 1.9, if you simply install an air conditioner, the floor temperature will not reach this level.
For example, if you set the room temperature to 20°C with the air conditioner, the floor temperature should be around 18°C.
However, in our houses, if the room temperature is 18°C, the floor is 20°C, and if the room temperature is 20°C, the floor is 22°C.
You can keep it.
I often say in my lectures that the ideal temperature for the head is 22°C, and the ideal temperature for the feet is 26°C.
The ideal temperature for the top and bottom is 4°C, which keeps your feet warm.
However, if you simply heat a well-insulated, airtight home with an air conditioner, your feet will be 2 degrees colder.
This is a deviation of 6 degrees from the ideal temperature difference between the top and bottom.
However, in our case, the temperature difference between the top and bottom is only 2 degrees warmer.
It's only 2 degrees.
This effect is so great that satisfaction is extremely high even at low room temperatures.
This is possible because the warm air from the air conditioner is circulating under the floor.
No matter how much insulation you put under the foundation, some heat will still escape downwards into the foundation.
This has also been made clear by detailed experiments conducted by my former laboratory at the University of Tokyo.
However, when we calculate the amount of heat that is escaping in terms of utility bills, we find that it is a very small value.
I understand. Also, this amount is calculated assuming a constant room temperature, and in reality, the floor is warm.
Many people are turning their air conditioners on less. Taking that into account, the amount of heat escaping under the foundation is probably
I think the effect will be offset or even greater.
We will properly calculate this and make it public at a later date.
There is one other major effect.
It is said that the better the insulation performance, the smaller the temperature difference between heated and unheated rooms.
In other words, the temperature in the changing room and toilet does not drop as much as in the living, dining, and kitchen areas.
These types of bathrooms are often used in cold weather as they are on the north side and are almost completely bare.
It would be nice if it was warmer than the living room, but the reality is the exact opposite.
It is said that a temperature below 3℃ is ideal, but the warm air will circulate throughout the room through the floor.
This temperature difference can be made smaller than that of a house with the same insulation performance.
Even if you put down solid wood flooring, what is the point in doing so if you are going to put down rugs and carpets?
It's hard to tell if it was made from natural wood, and I think it's a waste.
This would seem especially true.
In this way, considering various aspects, it is important that the entire floor is not cold, not only in houses with cold floors, but also in
It also has great benefits for homes where only a small part of the living/dining/kitchen area is warm, such as with underfloor heating.