## 1\. Introduction In China, building energy consumption accounts for about 30% of the total social energy consumption, and heating energy consumption, which occupies a large ratio in building energy consumption, has an important impact on the energy structure and environmental pollution \[1\]. The hot summer and cold winter zones account for about 20% of the national territorial area, in which the average temperature is lower than 5°C for nearly 90 days every year with an average relative humidity of about 75%, so the weather is cloudy and cold but without centralized heating \[2\]. With the improvement of living standards, different forms of decentralized heating have been initially set up for the residential buildings in hot summer and cold winter zones. The survey shows that the electricity consumption for decentralized heating in such areas increased from less than 100 million kW·hr in 1996 to 39 billion kW·hr in 2010 \[3\]. Since the Chinese government has proposed that the carbon dioxide emissions will peak around 2030 and be neutralized around 2060 \[4\], making it very important to take effective energy-saving measures to control the growth of heating energy consumption. There are many kinds of heat sources for decentralized heating, among which air-source heat pumps are characterized by cleanliness, high efficiency, and flexibility. A lot of Chinese and foreign scholars have extensively investigated the effects of operating parameters on the heating performance of air-source heat pumps, including water supply temperature \[5, 6\], number of times of starting and stopping heat pumps \[7, 8\], and operating frequency \[[9]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0009)\]. A system combining air-source heat pumps and solar energy was proposed for residential heating and domestic hot water supply. The energy-saving potential, thermal environment performance, and environmental protection benefits of the system have been explored through experiments and numerical simulations \[[10]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0010), 11, 12, 13, 14\]. Compared with conventional radiators, low-temperature heating radiators can improve the COP by 12%–18% for air-source heat pumps by retrofitting a low-rise multi-family house in Sweden, combined with ventilation heat recovery \[[15]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0015)\]. Xu et al. \[[16]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0016)\] proposed a novel device for an air-source heat pump/heat pipe room heating system and investigated the changes in the heating performance of the system at different outdoor temperatures. The results showed that the system could operate stably for a long time at outdoor temperatures from −1.5 to 3.3°C and indoor temperatures of 20 ± 1°C, and the system COP could reach 4.35–4.64. Different from centralized heating, under the decentralized heating mode with air-source heat pumps, users can set the operating parameters of the system or choose different operation control strategies to meet the personalized heating demand, thus giving full play to the advantages of behavior energy saving. Considering the release of additional loads from thermal storage in buildings and heating systems, more flexible intermittent operation should be used to improve energy efficiency and indoor thermal comfort under intermittent system operation \[[17]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0017)\]. The additional load under the intermittent operation would be employed to adjust the temperature of indoor air, furniture, and inner layers of building envelopes. Ghiaus and Hazyuk \[[18]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0018)\] proposed an optimal thermal load calculation of intermittently heated buildings to reject the disturbances. Pupeikis et al. \[[19]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0019)\] optimized the intermittent heating phases by setting the cooling down and reheating time. Their study concluded that the most effective energy-saving solution was to enlarge the heating power by around 50%. Xu et al. \[[20]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0020)\] showed that the largest heating capacity should be 10%–30% higher than the traditional design heating load, and the energy-saving rate could reach 25%–40% in a typical week. Bloomfield and Fisk \[[21]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0021)\] pointed out that the thermal inertia was the important factor affecting the optimization control of the intermittent heating, while optimizing the turn-on time had the higher efficiency than the turn-off time. Kim et al. \[[22]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0022)\] compared the on–off control and schedule control of the intermittent operation and showed that the on–off control could avoid temperature overshooting with the high thermal environment and obtain 25% and 37.9% energy efficiencies during the semester and winter vacation, compared with the schedule control. In recent years, air-source heat pump-based intermittent heating has attracted attention in order to reduce heating energy consumption. Xu et al. \[[23]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0023)\] established an integrated dynamic model for multiarea buildings and analyzed the influence of different terminals and building envelopes on indoor temperature change and intermittent heating energy utilization by numerical simulation. Related studies have shown that compared with continuous heating, air-source heat pumps-based intermittent heating presents different energy-saving potentials. A physical model for simulating and forecasting the thermal behavior of the building is developed using the state space method, and the heat-saving rate for intermittent heating can reach about 20% in a typical week compared with continuous heating \[[24]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0024)\]. A two-stage lumped parameter model is established to study the thermal dynamic process of intermittent heating, and a field test carried out in a residence in Cambridgeshire showed that the energy-saving rate of intermittent heating was only about 5% compared with continuous heating \[[25]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0025)\]. Xu et al. \[[26]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0026)\] showed that a maximum energy-saving rate of about 6% could be achieved by intermittently adjusting radiator valves according to living schedules. Benakopoulos et al. \[[27]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0027)\] pointed out that the continuous low-temperature control strategy resulted in similar energy savings to intermittent heating. A comparative study of continuous versus intermittent heating performed in Amman, Jordan, found that more comfort, more fuel saving, and lower initial and running costs were achieved when continuous heating at low temperatures was adopted \[[28]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0028)\]. Different heating terminals (fan coil, radiant floor, and radiator) show dissimilar influences on the indoor thermal environment and energy performance for intermittent heating \[[29]](https://onlinelibrary.wiley.com/doi/10.1155/2024/1661363?utm_source=chatgpt.com#bib-0029), 30, 31, 32\], and terminals with small thermal inertia are in favor to raise the indoor temperature rapidly and thereby has the larger energy saving potential, so the fan coil and radiator have the better adaptability for intermittent operation. Scholars have done a lot of research on intermittent heating, but few studies have involved the heating mode of office workers’ living places in hot summer and cold winter zones. Most of the hot summer and cold winter zones in China belong to noncentralized heating areas, being cold in winter with high outdoor humidity, which makes it necessary to set up decentralized heating to improve the indoor thermal environment. Considering office workers’ work and rest characteristics (going out early and coming back at dusk), it is evidently unreasonable to adopt all-weather continuous heating for the residences of office workers. In this study, a set of experimental heating systems combining air-source heat pumps and radiators (ASHP-R system) was set up in Hefei City. Referring to the work and rest time of office workers, a low-temperature intermittent heating experiment was carried out, the variation characteristics of thermal parameters and the thermal comfort of heating rooms were analyzed, and the economic and environmental benefits of the ASHP-R system were evaluated. The results are of great significance for further reducing the heating energy consumption of buildings.