Severe cold Corona infection control What to do with "ventilation"? What is the point?

It is extremely cold in various places, but according to the Meteorological Agency, it is easily affected by the cold this winter.

As the vigilance for Omicron strains grows, experts point out that it is important to keep the room temperature and humidity above a certain level for ventilation of the building.

We covered the site of trial and error and the points of ventilation.

Voices of "cold" from users of facilities for the elderly

The special nursing home for the elderly in Setagaya Ward, Tokyo, has a system to ventilate the entire building, but in addition, the corridors and dining rooms are ventilated every two hours for about 10 minutes throughout the day and night, and residents. It means that the room you spend in is also ventilated about 4 times a day when you leave the room for meals.

However, in the past, when residents complained that it was "cold", they sometimes closed the windows, so in November last year, more than 10 people including residents and staff were confirmed to be positive, so ventilation was provided. It means that we have confirmed the thorough policy.

In addition, we decided to put up a time zone in the corridors so that residents can understand the importance of ventilation.

On the other hand, with the recent cold weather, the number of users saying that it is "cold" has increased again, so in addition to raising the temperature of the air conditioner to around 25 degrees, we are careful not to lower the humidity using a humidifier. is.

Nobuhide Yamamoto, chief of the special nursing home for the elderly "Hakusui no Sato", said, "The current situation is that when users complain that it is" cold, "it opens and closes. But I'm worried about the colder weather, especially when it rains or snows. "

Expert "Room temperature 20 degrees and humidity 40% or more in facilities for the elderly"

Experts investigating buildings and health about ventilation precautions in the winter point out that you should be aware of "too low temperatures and humidity."

The point is that the room temperature is 20 degrees and the humidity is 40% or more.

A research group of Professor Toshiharu Ikaga of Keio University Faculty of Science and Technology, who is conducting research on the relationship between building structure and health, is conducting research on changes in health status between temperature and humidity and winter at 14 pay nursing homes in Kinki. I investigated how it was related to.

As a result, ▽ when the room temperature of the private room is below 20 degrees, the degree of care required is 1.5 times worse than when it is 20 degrees or more, and ▽ when the humidity is below 30%, the degree of care required is higher than that of the facility of 30% or more. Was twice as easy to get worse.

Professor Ikaga said, "Ventilation is very important, but there is a concern that the temperature and humidity will drop too much if ventilation is done unnecessarily in winter.

Especially in old facilities, the heat insulation may be insufficient, and at night due to drafts, There are disadvantages such as lowering the room temperature and humidity, making it easier to get cold and influenza, raising blood pressure, and lowering the quality of sleep. "

On top of that, it is important to keep "room temperature 18 degrees or higher and humidity 40% or higher" in general households, and "room temperature 20 degrees or higher and humidity 40% or higher" in facilities for the elderly and households with elderly people.

It's easy to think that the room temperature doesn't fall below 20 or 18 degrees Celsius, but Professor Ikaga points out that "be careful in most homes."

▽ At night, in addition to keeping the temperature and humidity with a heater or humidifier, it is also important to take room data with a thermometer or hygrometer.

"Winter can be ventilated in a shorter time than summer"

What are some ways to ventilate a room without lowering it too much?

According to Daikin Industries, a major air-conditioning manufacturer, most air-conditioners cannot be ventilated due to the mechanism that warms and returns the air in the room, so the windows are opened with the heating turned on to take in the outside air. Is necessary.

It is said that there are three points to effectively ventilate the room.

▽ The first is to turn on the heating to warm the room and then open the windows.

If the walls and floor of the room are warm, it will be difficult for the room temperature to drop.

▽ The second is to reduce the width of the window if you keep opening it, and use an air purifier together.

Regarding air purifiers, the Ministry of Health, Labor and Welfare states that it is necessary to use a filter with a small mesh called "HEPA filter" and to have an air volume of 5 cubic meters or more per minute.

▽ The third is to shorten the ventilation time and perform it at short intervals.

In winter, the temperature difference between the room and the outside is larger than in summer, and the wind is often strong, so ventilation can be done in a shorter time than in summer.

For example, it means that the temperature change can be made smaller by ventilating for 5 minutes or less every 30 minutes rather than ventilating for 10 minutes every hour.

Mr. Shuyuki Shigemasa, a public relations group of Daikin Industries, said, "Opening a window as far away from the air conditioner makes it difficult for warm air to go outdoors and at the same time saves electricity bills."

Utilization of "range hood"

In addition, "FUJIOH", which manufactures range hoods installed in kitchens, also introduces ventilation methods using range hoods.

When simulating in a room of about 35 square meters, which is about 9 tatami mats, it takes about 37 minutes to replace the air when operating with "constant ventilation" where the air volume is weak, and 9 minutes when operating with the range hood "strong". It took longer, but the room temperature didn't drop much, and on average it was about 3 degrees higher than when driving at "strong".

When using a range hood, it is important for "FUJIOH" to open the "air supply port" installed in the room. ▽ If there is a pillar or wall between the air supply port and the range hood, sufficient ventilation is provided. In addition to the possibility that there will be places where you cannot do it, please be aware that it will take longer to ventilate when the room becomes larger.