Attic air conditioning cooling and underfloor air conditioning heating

Effective combination of attic air conditioning cooling and underfloor air conditioning heating

Underfloor air conditioning heating

The main feature of underfloor air conditioning heating is that it warms the floor . No matter how well-insulated and airtight a house is built, if you're using wall-mounted air conditioners for heating, your feet tend to get cold. With underfloor air conditioning heating, a major advantage is that it makes it easier to keep the entire house warm through the underfloor space , including not only the living room, dining room, kitchen, but also the bathroom, dressing room, and even the toilet . However, since the temperature is below 24℃, there are no restrictions on the type of flooring, unlike underfloor heating, and a major advantage is that you can use solid wood flooring as usual .

I believe Professor Nishikata from Akita was the first to introduce underfloor air conditioning heating, and I was the second. After that, an article I wrote was published on page 75 of the April 2012 issue of Kenchiku Chishiki (Architectural Knowledge), and the number of construction companies that copied it skyrocketed. I think it sparked a huge boom with over 1000 companies nationwide trying to imitate it. However, underfloor air conditioning heating requires insulation and airtightness with a Q value of at least 1.9 (or UA value of 0.57 or less) and a C value of 1.0 or less , and it won't work unless proper instruction is given on how to operate the heating system , so many construction companies failed as well.

Heating an entire house while keeping heating costs down depends on insulation, airtightness, solar heat gain, and, most importantly, the selection and operation of the appropriate air conditioner capacity . Our company has a long history of expertise in this area, and many construction companies seek our know-how. While technically very simple, keeping heating costs down with underfloor air conditioning is not easy.

If you only use one underfloor air conditioning unit, and you set the first-floor floor temperature to 24°C, the room temperature on the first floor will be around 22°C, and the second floor around 20°C. Also, most houses have large south-facing windows. This means that on sunny days, you can maintain a temperature of 20°C or higher from 7 AM to at least 7 PM, even with the heating off during the day . Some people dislike the warm air from air conditioners, but they are not even on during the day. At night, you sleep on the second floor, so you don't even feel the warm air at all, which is a big advantage.

Furthermore, since we use standard models found in regular catalogs, replacement and maintenance are easy even after 10 years. Some people worry about dirt under the floor, but we have inspected the underfloors of many houses that are about 10 years old, and they are almost as clean as when they were new, with no problems whatsoever.

The next thing people start saying when they start living in a warm, well-insulated house is that it's "dry". This can be easily avoided if you plan to humidify the entire house from the beginning. If you can humidify properly, it's not only good for your skin, but it also reduces your chances of catching a cold or the flu.

Attic air conditioning cooling

Even more than heating, the Japanese housing industry is completely lacking in cooling and dehumidification planning.Less than 2% of companies have a proper cooling plan for each room on the second floor.It seems.

Most people want the living room, dining room, kitchen (LDK), bedrooms, and even the dressing room (though the time spent there is short) to be comfortable. If we consider only a couple, the bedroom refers only to the master bedroom, but once children start using their own rooms, their rooms are also perfectly valid bedrooms. Of course, installing air conditioners in each room would solve the problem, but it would be extremely expensive, and in high-performance homes, even the smallest 6-tatami mat size air conditioner would be significantly overkill . Furthermore, the exterior would look unsightly with pipes and outdoor units everywhere. As a result, fuel efficiency would be significantly worse, and moreover, installing air conditioners in each room would result in excessively cold air, which is a major cause of air conditioning sickness and discomfort.

To address this issue, we employ a method called "attic air conditioning." We install one air conditioner in the attic to cool it down . This cool air is then distributed to each room using a fan. At this time, the room temperature will be approximately 24°C in the attic, 27°C on the second floor, and 27°C on the first floor. In a highly insulated, airtight house with perfect solar shading, using attic air conditioning will keep monthly cooling costs to around 4000 to 5000 yen for most households , even if the air conditioner is left on continuously for the entire month of August . In our houses, however, adopting the common lifestyle of turning off the air conditioning occasionally and using it in conjunction with ventilation to avoid wasting it will actually increase cooling costs. When you are sleeping, the air conditioner is only running weakly in the distance, and only a small breeze is distributed to each room by the fan. Therefore, the indoor environment becomes close to "neutral," where you don't feel the heat or coolness as you would in spring or autumn . Naturally, you 'll also be virtually free from air conditioning-related illnesses and dust mites and mold, which are difficult to prevent in high-humidity environments .

Furthermore, when the air conditioner is turned off, up to 700g of moisture accumulates inside. This is not hygienic. Our company uses air conditioners that can sterilize by heating at over 50℃ as standard, so if you heat sterilize them for about an hour once a month, you can eliminate more than 99% of any mold that may grow inside . This means that professional cleaning, which costs around 20,000 yen every few years, is basically unnecessary. Compared to installing air conditioners in each room, the replacement cost is also very low as you only need to replace one unit.

The polar opposite of underfloor air conditioning for heating, attic air conditioning for cooling is very easy to keep cooling costs low, but technically it is very difficult. There is a reason for this. Unlike the first floor, the rooms on the second floor are divided into individual rooms. Also, most people close the doors to each room when they go to sleep. In order to make it work evenly in this situation, it requires a series of subtle design ideas that are not obvious just by looking. If a construction company that does not know how to do this just tries to copy the form, there is a high probability of failure.

In this way, it is ideal to combine attic air conditioning cooling with underfloor air conditioning heating.

In particular, attic air conditioning for cooling is effective in the summer, and underfloor air conditioning for heating is effective in the winter.

By using both an attic air conditioner for cooling and an underfloor air conditioner for heating, you can create a more comfortable living environment.

Underfloor air conditioning heating is gaining attention as a way to take advantage of the benefits of both attic air conditioning cooling and underfloor air conditioning heating.