Getting through the cold winter will save you more money if you dress correctly than if you raise the temperature of your heater.

With the arrival of full-fledged winter, there are more opportunities to use heating appliances such as air conditioners, and many people must be feeling the rise in electricity bills. To survive such a cold winter,

Low-tech Magazine summarizes that it is overwhelmingly more economical to wear the right clothes than to use a house with high insulation performance or a heater with high energy efficiency.

Insulation: first the body, then the home - LOW-TECH MAGAZINE

Over the last few decades, the relative efficiency of home insulation and heating appliances has improved, resulting in significant reductions in energy consumption. For example, in the United States, despite population growth and improved comfort levels, heating energy consumption declined by about 19% from 1993 to 2005, a similar trend in other developed countries. It seems that you can see it.

Heaters still consume a large amount of energy, most of it reliant on fossil fuels. There are also claims that state-of-the-art home furnishings with better insulation can reduce energy consumption, but most of these claims are based on the idea that the energy consumption of demolishing old buildings and building new homes should be taken into account. No,” points out Low-tech Magazine.

In addition, homes that use state-of-the-art insulation materials and energy-efficient heating appliances are expensive in the first place, so not everyone can afford them.

A simple way to deal with these problems is to lower the heat setting and wear more clothes. The extent to which energy consumption can be saved by lowering the heating temperature setting varies depending on the outdoor temperature, but even in warm climates, a 1 degree lowering of the heating temperature can save about 9-10%. It

turns out that it is possible to save energy consumption.

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommends setting the room temperature in winter between 21 and 23 degrees Celsius. According to a Dutch report, average winter temperatures rose from 20 degrees Celsius in 1984 to 21 degrees Celsius in 1992. While these data may not be enough to prove that temperatures are rising, it's not hard to imagine that improvements in heating appliances have increased comfort levels for many people over the years.

Between 1993 and 2005, the energy consumption of heating appliances was reduced by around 20%. However, this only saves as much energy as lowering the temperature setting of the heater by about 2 degrees. Low-tech Magazine recommends lowering your heater temperature and wearing clothes, as you can cut your energy consumption by 35% by lowering your heater temperature from 22°C to 18°C. There is.

In the first place, the body temperature in the deep part of the human body is about 37 degrees Celsius, but the skin temperature is around 33 to 34 degrees Celsius. The skin temperature drops because the ambient temperature is lower than the body temperature. Heat is released through breathing and skin, but most of it is through the skin, and many non-human animals are covered with hair and feathers to prevent this.

Wearing clothes is necessary to prevent heat radiation from the skin, but the clothes themselves do not generate heat, but only prevent body temperature from escaping to the outside. This is caused by warming the layer of air between the skin and clothes, and air is an excellent insulator because it has relatively poor thermal conductivity. In fact, your home's insulation system basically uses air in the same way. The difference between the heat insulation method of a house and that of a person is that, in the case of a human, it is necessary to make the clothing that wraps the skin light and easy to move so that the body can move, but in the case of a house, it is necessary to move and seek comfort. It is possible to use hard and bulky materials because there is no

The insulation properties of clothing can be expressed in units of 'clo'. Although this is not a standard international unit, 1 clo is equivalent to 0.155m²K/W and has the same insulating effect as wearing a three-piece business suit (shirt, pants, jacket) and light underwear. In addition, 1clo means the insulation property that can be comfortably spent in an environment of 21 degrees Celsius. In Europe, there is a similar insulation property unit called 'tog', which is equivalent to 1 tog = 0.645 clo. It can also be compared with the 'R' of building insulation materials, where 1clo = 0.88R.

According to the Encyclopedia of Occupational Safety and Health, the insulation properties required to maintain a neutral temperature sensation are approximately '2.7clo' at a room temperature of 10 degrees Celsius, and the insulation required when the room temperature drops to 0 degrees Celsius. It seems that the characteristics will rise to '4clo'. According to ASHREA, every time the room temperature changes by 1 degree, the insulation properties of the clothes also change by about '0.18 clo'.

Rough clo values for each type of clothing according to ASHREA are as follows. By simply summing the clo values of the clothes you are wearing, you can calculate the insulating properties.

Short- sleeved T-shirt: 0.10clo
Sleeveless underwear: 0.06clo
Bloomers for women: 0.20clo
Short- sleeved shirt: 0.15-0.25clo
Long- sleeve shirt: 0.20-0.30clo
Trousers: 0.25-0.35clo
Long skirts and robes: 0.22-0.77clo
Sweater: 0.30clo
Brief: 0.05clo
Socks: 0.04-0.10clo
Long sleeve underwear: 0.20-0.35clo
Tights: 0.20-0.35clo

In addition, Low-tech Magazine states that the clo value is equivalent to 0.15 times the weight of the clothes (unit is pound), while saying that it is 'a general rule of thumb'. However, due to the development of material engineering, light clothing with a high clo value has also appeared, says Low-tech Magazine. Functional innerwear such as HEATTECH, which is extremely popular in Japan, is one of the “lightweight and high clo value clothing”. Although there are no documents that accurately document the clo value of functional innerwear, it is estimated to be about twice as much.

In addition, long t-shirts and tights that fit snugly on the body have the best 'pumping factor'. The pumping coefficient is another factor that defines a garment's insulating properties in addition to the clo value, and is a measure of the movement of air caused by the movement of the wearer. For example, tight-fitting underwear has a much better pumping coefficient than loose-fitting clothes such as ponchos and wide pants, so even clothes with similar clo values actually have a high pumping coefficient. seems to be higher. In addition, since 'multiple thin air layers' are more effective than 'single large air layers', wearing underwear and clothing with a high clo value will increase the heat insulation effect. can be expected.

According to the survival book of the US Air Force, if you wear two long pants (0.25 to 0.35 clo) on top of each other, it will be '1.5 clo', which will jump to more than double the clo value and increase the insulation effect at once.

In addition to room temperature, the required clo value changes depending on whether the person is sitting still without moving the body or performing light actions such as typing. For example, if the room temperature is 10 degrees Celsius, '2.7 clo' is required if you are not moving your body, but if you are doing light activities such as typing, the required clo value will drop to about '1.7 clo'. it is. According to Low-tech Magazine, comfort temperature drops by about 1.7 degrees for every 30 watts increase in heat production.

However, the temperature at which people feel comfortable varies greatly not only by gender and age, but also by individual, so it is better to use the necessary clo value only as a reference. Still, Low-tech Magazine notes that the insulation properties of properly dressed clothing can have a non-negligible effect, making them very effective in saving money.

in Note, Posted by logu_ii