A、A naturally ventilated office is more comfortable. B、A cool office will boost employees’ productivity. C、Office air-conditioni

Setting the office air-conditioning at about 22℃ has become standard practice across the world. Numerous guidebooks across the world on heating, ventilation and air-conditioning claim office performance peaks at 22 degrees. Many people indeed find relief from soaring summer temperatures in air-conditioned offices. But recent studies have challenged the accepted wisdom that a cool office is more productive.
The reality is more complex. Researchers conducted a review of all studies relating to air-conditioning and productivity. They found that 22 degrees was probably a little chilly, even at the height of summer. For a person dressed in typical summer clothing, an optimal range would be between 23 and 26 degrees. And people can even tolerate temperatures beyond this comfort zone as long as they can adjust their clothing and expectations. In fact, even on very hot days, it makes sense to turn the air-conditioning up. People often chase just one optimum temperature, and this is understandable when people feel hot. But there is a range of at least three to four degrees which does not have any adverse impact.
Another issue related to this is that people can become psychologically dependent on air-conditioning. If they’re used to the environment which is air-conditioned, they tend to prefer lower temperatures. But the studies found that almost all humans became accustomed to the new temperature. It was only at the extreme ends of the temperature range where people’s productivity suffered. This range was above 26 degrees and below 19 degrees.
Questions 12 to 15 are based on the passage you have just heard.
12. What is the accepted wisdom concerning the office environment?
13. What did researchers find from their review of all studies relating to air-conditioning and productivity?
14. What do we learn about using a little less air-conditioning during hot weather?
15. What happens when people are used to an air-conditioned environment?