“As the “gas shortage” spreads, how warm should the underfloor heating be set?

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The worsening energy crisis in the southern regions has made users of underfloor heating once again pay attention to a topic that was not previously a concern – namely, the setting of indoor temperatures. Because aside from comfort considerations, rising temperatures mean higher heating costs. One issue they must face is: setting the indoor temperature, which for most users of central heating systems is something that doesn’t need to be considered. However, for most underfloor heating users, especially those with individual temperature control, this is a procedure that they cannot avoid when operating their underfloor heating system. But how exactly should the indoor temperature be set? Most people who use underfloor heating are confused; many of them actually enjoy the warmth provided by this system without really understanding how it works. 　　16℃: A symbolic reference value. For most underfloor heating users, they may operate their heating systems in a somewhat haphazard manner, but they still have a clear reference value in mind – 16℃. This used to be the minimum temperature during the centralized heating period in many cities in the north. However, many people do not know what the basis for this data is or how reasonable it is. “\"Warm like spring\" is the most common description people use for the ideal temperature in winter. In climatology, spring refers to the period during which the average temperature over a period of 5 days is between 10°C and 22°C. It can be seen that 16°C should be the average temperature in spring, and it makes sense to use this temperature as the minimum heating level during winter central heating. 　　But just as the relative humidity in the air affects people’s perception of the air temperature, factors such as the air flow velocity near the body, an individual’s living habits, level of activity, clothing, age, and health status also influence how one perceives the indoor temperature. Therefore, the lower temperature limit of 16 degrees Celsius means different things to different people: as long as the room temperature remains above 16 degrees Celsius, some people can spend the winter comfortably ； Setting the heating standard at no less than 16 degrees Celsius will inevitably cause suffering for another group of people. Related studies have found that in winter, when the indoor air temperature is 18°C, half of the people feel cold while sitting. Research on the \"physiological zero temperature\" also confirms this: for healthy people, their physiological zero temperature, at which they feel neither hot nor cold in winter, lies between 18°C and 20°C (while it is between 28°C and 29°C in summer). Obviously, there is an unreasonable element in the lower temperature limit of 16°C. In fact, as people’s demands for a higher quality of life continue to rise, residents in some cities have in recent years called for raising the lower temperature limit to 16°C. In response to this demand from their citizens, the legislative bodies of some cities have shifted the goal of central heating from one that was merely sufficient to prevent people from dying or getting severely injured due to cold, to one aimed at improving residents’ heating comfort and quality of life. As a result, the required indoor temperature has been raised from 16°C to 18°C. Today, cities such as Qingdao, Heilongjiang, Beijing, and Tianjin have all raised the minimum temperature for indoor heating in winter from 16°C to 18°C. 　　10%: An energy-saving figure that must be taken into consideration. Once the scientific basis behind the reference temperature of 16°C is understood, it becomes logical for users of underfloor heating to determine the desired indoor temperature: using 16°C or 18°C as a reference, and applying the principle that \"the designed temperature for a room with underfloor heating can be 2°C lower than that of a room with radiators,\" setting 14°C or 16°C as the baseline indoor temperature. This baseline value is then increased gradually until the temperature becomes unbearably hot. However, things are not that simple. Because relevant studies show that for every 1-degree increase in indoor temperature, energy consumption increases by about 10%. This means that the heating costs that users have to pay will also increase accordingly. Since most users of underfloor heating systems that currently have the capability for individual temperature control use natural gas as a heat source, and given the increasing prevalence of gas shortages, such users will have to give more consideration to conserving natural gas when setting the indoor temperature. 　　Since the onset of winter this year, historically rare heavy snows and blizzards* have hit various provinces and regions in our country, leading to shortages in natural gas supply across the area. According to media reports, during peak gas consumption days, Wuhan, Hangzhou, and Nanjing experienced shortages of natural gas amounting to 600,000 cubic meters, 480,000 cubic meters, and 500,000 cubic meters respectively. To ensure a supply of gas for residents’ use, Wuhan **successively cut off the natural gas supply to 56 industrial and commercial enterprises as well as 26 taxi fueling stations; Hangzhou temporarily suspended supply to 38 enterprises and reduced supply to 2 enterprises within half an hour. What worries heating system users is that in cities where there are severe gas shortages, those who use natural gas as a heat source for their heating systems find themselves in a very difficult situation. 　　It is reported that during periods of severe gas shortages in Wuhan, many residential complexes used underfloor heating systems powered by natural gas for heating, which resulted in insufficient pressure in the piping systems in these complexes and affected residents’ ability to cook. In response, Wuhan Natural Gas Company once reminded citizens that, for the sake of other residents, it was hoped that they would avoid using natural gas for heating during this period. A similar scenario also occurred in Zhengzhou. Fearing restrictions on the use of natural gas, many residents in Zhengzhou have canceled their plans to install wall-mounted boilers with underfloor heating systems. A wall-mounted boiler dealer in Zhengzhou revealed that since November 15th, not only has he failed to sell a single wall-mounted boiler, but many customers have also come to return them. 　　Heaters users understand that what is happening to them in Wuhan and Zhengzhou may be temporary, but the alarm to conserve natural gas use has sounded; this means that when setting the indoor temperature, they must adhere to the principle of \"reducing natural gas consumption as much as possible while still ensuring a comfortable temperature for humans,\" and set the indoor temperature in a scientific and cautious manner. 　　In fact, abroad, there have already been precedents of continuously lowering indoor temperatures to save energy. According to media reports, in order to reduce oil consumption, France **used to set a heating temperature limit for residents at above 22°C; after the first energy crisis in 1975, this limit was reduced to 20°C, and after the second energy crisis in 1978 it was lowered to 19°C. The current limit is 18°C. HVAC design, load calculation – Hangzhou Wangjin Technology: http://www.wjcad.cn Email: hzwjkj@163.com