Air conditioning cooling to 26 degrees Celsius is the most power-efficient, this year is the coolest year of the next decade...
When the autumn wind rises, these rumors should also cool down
In the past August, the heat was unbearable, and many people were tortured by the high temperature, and they hid in air-conditioned rooms every day to "continue their lives". However, the scorching sun has not affected the activity of the rumors, and they are still making waves on the Internet: the air conditioner is cooled to 26 degrees Celsius, the most power-saving, this year is the coolest year in the next decade, and the cooling spray has zero harm...
With the end of this year's three-volt day, all parts of the country also have a hint of autumn coolness, today the Science and Technology Daily reporter will take stock of the rumors in August one by one, let the autumn wind give them to go to the "heat".
Air conditioning cooling to 26 degrees Celsius most power savings?
Truth: The higher the temperature you set, the less power you consume
In the past month, the high temperature weather that lasted for many days has made the air conditioner a "life-saving artifact" for many people. However, while many people are blowing air conditioning, they are also distressed about the electricity bills that are "rushing" away. There has been a saying on the Internet that "the air conditioner is the most energy-saving to 26 degrees Celsius", and this power-saving "home remedy" has been tried by many people.
In this regard, Zheng Zhongyuan, head of the environmental protection professional of the State Grid Tianjin Electric Power Research Institute, said in an interview with the Science and Technology Daily reporter that the statement that the air conditioner is set at 26 degrees Celsius is the most power-saving statement is unfounded, and the power consumption of the air conditioner is affected by many factors.
First of all, the power consumption is related to the temperature set by the air conditioner. Someone has calculated that if the refrigeration temperature of the air conditioner is reduced from 26 degrees Celsius to 25 degrees Celsius, the power consumption will increase by 47.89%; If the temperature set by the air conditioner drops from 27 degrees Celsius to 25 degrees Celsius, the power consumption will increase by 134.35%. Therefore, only by raising the refrigeration temperature of the air conditioner will the power consumption decrease. "In other words, the lower the temperature of the air conditioner setting, the greater the power consumption." Zheng Zhongyuan said.
Secondly, the power consumption of air conditioners with different horses and energy efficiency is also different. First-class energy-efficient air conditioners are more power-efficient than third-level energy-efficient air conditioners; The higher the number of air conditioners, the faster the cooling, but the greater the power consumption.
Finally, the power consumption of air conditioners is also related to the outdoor temperature. If the indoor and outdoor temperature difference is too large, it will also increase a certain amount of power consumption. Usually when the indoor temperature and outdoor temperature difference is about 4 degrees Celsius, the air conditioner is more power-efficient.
Zheng Zhongyuan introduced two tips for air conditioning and power saving. "Adjusting the air conditioning blade to blow the air upwards, because the cold air is heavy, it will sink, so it is easier to spread the coolness into the room than to blow cold air directly to the ground." In addition, the air conditioner can also be used with a fan to spread the cold air to all corners of the room. Zheng Zhongyuan said that both methods can quickly reduce the indoor temperature to the set temperature, reduce the operation of air conditioning, and thus save electricity.
Is this the coolest year of the next decade?
Truth: The thesis does not cover future temperature predictions
This summer, the topic of high temperatures has not been broken, and the highest temperature record has been broken again and again, making people "hot". A hot search that appeared at the end of August, "This year may be the coolest year in the next 10 years", even more frightened netizens. The self-media that released the relevant news said that the source of the conclusion was a paper published in Nature Communications by the Institute of Atmospheric Physics of the Chinese Academy of Sciences. The paper said that in the future, the subtropical high pressure in the northwest Pacific Ocean will be further strengthened, which will further lead to extreme weather.
Subsequently, the Institute of Atmospheric Physics of the Chinese Academy of Sciences "personally went down" to refute the rumor that the paper studied the relationship between greenhouse gases and climate change, did not involve the problem of temperature prediction in the next 10 years, and did not propose or support the conclusion that "this year is the coolest year in the next 10 years".
"Long-term climate change projections by the end of the century require the use of climate models, but the results of the current models remain uncertain due to the level of scientific and technological development." The Institute of Atmospheric Physics of the Chinese Academy of Sciences said in an article on its official microblog.
Although there is no saying that "the coolest year in the next 10 years", the heat of this summer is real. According to the monitoring and assessment of the National Climate Center, taking into account the average intensity, scope and duration of high temperature heat wave events, as of August 15, the mainland high temperature event has lasted for 64 days, the longest since 1961; High temperature coverage above 40 degrees Celsius is the largest in history.
The reason for this extreme situation, Zhang Renhe, an academician of the Chinese Academy of Sciences and vice president of Fudan University, has explained that the "Arctic warming amplification effect" is an important reason for exacerbating extreme weather in Eurasia and North America.
In addition, Li Xichen, a researcher at the Institute of Atmospheric Physics of the Chinese Academy of Sciences, said in an interview with the media that a direct cause of extreme summer heat is the global warming caused by the change of radiative forcing caused by greenhouse gas emissions. Greenhouse gases such as carbon dioxide and methane emitted by human activities can absorb and emit infrared rays, causing continuous warming of the earth's surface and global warming.
Cooling spray zero hazard?
Truth: There is a risk of explosion or fire
"Go out for 5 minutes, sweat for 2 hours" - this is a true portrayal of people going out on three volt days this year. Not only people but also cars are baked by the scorching sun. The car basks in the fiery sun for a while, and the inside of the car is like a steamer, making the driver and passenger unbearable. In order to alleviate the high temperature, many motorists have purchased cooling sprays online, and some buyers say that spraying them in their cars can "quickly cool down and have zero harm". So, is it really a safe "cooling artifact"?
"The reason why the cooling spray has such a 'magical' cooling effect is mainly due to the principle of water mist evaporation and heat absorption." Zhang Sheng, a professor at the School of Chemical Engineering of Tianjin University, said in an interview with the Science and Technology Daily reporter that the main component of the cooling spray sold online is water, and a small amount of ethanol (alcohol), menthol and other organic substances will be added. Since water and alcohol "absorb" heat from the surface of an object, the heat is taken away after it evaporates. "It's the same thing we feel when we apply alcohol to our skin before the injection." Zhang Sheng said.
In addition to this, there are some sprays that can quickly cool down made of liquefied petroleum gas, the main components of which are propane and butane. "The boiling point of propane is minus 42.1 degrees Celsius, and the boiling point of butane is minus 0.5 degrees Celsius, and they can instantly vaporize and absorb a lot of heat in a high temperature environment, so that the surface of the object can be rapidly cooled, and the minimum can reduce the local temperature to below 0 degrees Celsius." Zhang Sheng said.
Although the cooling effect is good, the cooling spray is not what people call zero harm, but there is a huge safety hazard. "Liquefied petroleum gas and alcohol are flammable and explosive substances, and once they are not handled properly, they can easily cause dangerous accidents and become the fuse of disasters." Zhang Sheng reminded that especially in the summer, the temperature in the car is higher after being exposed to the sun, and placing the flammable and explosive cooling spray in the car is likely to cause an explosion, and in addition, the spray may also cause a fire if it encounters an open fire.
Zhang Sheng suggested that the public should try to avoid choosing cooling spray products containing highly flammable components such as liquefied petroleum gas or dimethyl ether. When using the cooling spray with water and ethanol as the main component, it is necessary to ensure that there is no open flame within the scope of use, such as in the car, the window should be opened for ventilation in time after use, so as to prevent the accumulation of flammable components in the car and cause safety accidents.
Washed bayberry discoloration is due to the addition of dye?
Truth: It is its abundant anthocyanins that change the color of the water
The hot weather makes many people have no appetite, and bayberry has greatly increased their appetite because of its sweet and sour taste.
However, when cleaning bayberry, many people found that the water for washing bayberry will soon become pink, purple or light pink, which also spreads the saying that "washing bayberry is due to the addition of dyeing agent to bayberry".
In this regard, Wang Qiang, executive deputy director of the Agricultural Product Quality Inspection Center (Hangzhou) of the Ministry of Agriculture and Rural Affairs, said that the situation of dyeing bayberry is almost impossible. Bayberry is wrapped in no outer fruit skin and the flesh is exposed, and if you want to dye it, you can only soak it in the dye or spray it with dye. However, spraying is difficult to achieve uniform coloring, and soaking will accelerate the rot and deterioration of bayberry. In addition, increasing the dyeing link will also increase the cost, which has no substantive significance.
If there is no dye, then what is the discoloration of washing bayberry?
"The flesh of bayberry is rich in anthocyanins, and anthocyanins are extremely soluble in water, and the pink, purple or pale pink we see is the color of anthocyanins dissolved in water." Wang Qiang introduced that the cell wall of the flesh of the bayberry is relatively thin, when the bayberry is rinsed with water or scrubbed with the bayberry, it is easy to cause the cell wall to be damaged, and the anthocyanins flow out and dye the water with color.
Wang Qiang suggested that the public can soak the bayberry in water mixed with starch and salt, which can stimulate the fruit fly larvae to run out automatically, and the starch can adsorb the larvae and other impurities, soak for about 20 minutes, and then rinse the bayberry with water. (Reporter Chen Xi)
Source: Science and Technology Daily