Heat pump air heater is not a new term. As early as several years ago, Professor Jiang Yi of Tsinghua University proposed this concept. He also proposed: "In the implementation of coal-to-electricity, can each household pay 10,000 yuan out of pocket and 1,000 yuan in electricity costs?" What Academician Jiang Yi referred to was the heat pump air heater.

Since the end of last year, air heaters suddenly became popular. The reason is simple: after Beijing, Tianjin and other provinces and cities provided high subsidies for air-source heat pump water heaters, other provinces found it difficult to replicate due to financial constraints, and subsidies in most areas were below 10,000 yuan. Therefore, heat pump air heaters, which are relatively much lower in price, were pushed to the forefront.

What is a heat pump air heater?

At present, there are mainly two forms of air-source heat pump heating promoted in rural areas. One is an air-source heat pump hot water system unit for each household; this is currently the most widely used on the market, and the vast majority are of this form. The other is a heat pump air heater for each room, which is currently used in a small number of pilot applications.

The air heater is similar to a household cooling and heating air conditioner. The difference is that an ordinary air conditioner will experience energy efficiency attenuation at -5°C and needs to use electric auxiliary heating, making it difficult to meet the heating needs of northern regions; however, the air-source heat pump air heater is specially developed for northern heating regions, and at an outdoor temperature of -20°C, its heating capacity does not attenuate. Moreover, it uses a floor-standing fan coil unit to supply air from the bottom of the room, avoiding the problem of hot head and cold feet when using an air conditioner.

In the past two years, through tests in more than 200 rural households in Beijing using air heaters combined with floor-standing fan coil units, the entire winter electricity consumption of each household was around 2,500 kWh, the indoor temperature could be above 15°C, and the COP could still be above 3 when the outdoor temperature was 10°C. Not to mention calculating at the low electricity price of 0.1 yuan/kWh, even at the agricultural electricity price of 0.49 yuan/kWh, it is just over 1,000 yuan, similar to coal-fired heating.

So, compared with current air-source heat pump heating machines, how does the air heater work? What are its advantages and disadvantages? What are the market prospects for 2018? These are questions many people want to know. Next, let us understand the air heater together.

What is the difference from heat pump heating machines?

Principle: Like an air-source heat pump, the air heater is also a high-efficiency heat energy upgrading and transfer device based on the reverse Carnot cycle. It uses a small amount of electrical energy as power and transfers low-temperature heat from outdoor air to indoor air through refrigerant to achieve indoor heating.

Compared with heat pump heating, the air heater raises indoor temperature through heat exchange between high-temperature refrigerant and indoor air, while the air-source heat pump water heater raises water temperature through heat exchange between refrigerant and water, and then raises indoor temperature through the circulation of hot water at the terminal.

Implementation standards: Air-source heat pump heating units implement the national standard GB/T25127.2-2010. The nominal heating condition is dry-bulb temperature/wet-bulb temperature -12°C/-14°C (outlet water temperature on the use side 41°C), the nominal heating coefficient of performance (COP) is not lower than 2.1, and the heating IPLV(H) is not lower than 2.4; however, there is currently no relevant national standard for heat pump air heaters. The nominal heating condition is outdoor dry/wet-bulb temperature -12°C/-13.5°C; the ultra-low-temperature heating condition is outdoor dry-bulb temperature -20°C, and the applicable range is -25 to 43°C.

Components: There are also differences in components. For example, for the condenser, the air heater uses an air-cooled copper tube finned condenser, while the air-source heat pump heating machine uses a water-cooled high-efficiency tank, plate heat exchanger, or tube-in-tube condenser.

Working mode: The heat pump heating machine supplies heating through hot water circulating at the terminal and can be combined with various terminals such as floor heating, radiators, and fan coil units. Generally, one household only needs one main unit to heat multiple rooms at the same time; while a set of air heaters itself is a matched outdoor unit and one indoor unit. At present, one air heater can only solve the heating of one room, and multiple rooms require the purchase of multiple sets of equipment.

For example: for a 100 m² building with one household, three bedrooms, and one living room, if both the living room and bedrooms need heating, one 5P heat pump heating machine with terminals can meet the need, while using air heaters would require four sets.

What are the advantages and disadvantages?

Advantages: Compared with water-system air-source heat pump products, the biggest advantage of the air heater is that the investment cost is much lower, which provides more choices for areas under great financial subsidy pressure;

Second, air heater heating only involves the refrigerant circuit system and has no water circuit system, so installation is simpler and maintenance is more convenient. Moreover, it is not troubled by problems such as water pipes freezing, and the system is more stable;

Third, in terms of heating time, the air heater directly supplies air to the room, and after startup it can quickly achieve the required heating effect, while the heat pump heating machine first heats water and then transfers heat through hot water, so the heating speed is slower. Especially for floor heating, there is an additional heating and heat storage layer, and the first heating usually takes more than ten hours or even longer. For some places with rapid heating needs, the air heater is more suitable.

Disadvantages: The disadvantages of the air heater are also obvious, that is, comfort is much worse. It is precisely for this reason that in some areas with relatively better government finances, such as Beijing, Tianjin, Shanxi, and Hebei, air-source heat pump water-system products are still mainly used, and air heaters are currently rarely applied.

In addition, one set of heat pump air heaters can only solve the heating of one room, and multiple rooms require the purchase of multiple sets of air heaters (some companies have launched one-to-many models, but performance and prices are temporarily unclear).

What are the prospects for air heaters in 2018?

Since 2016, Beijing's coal-to-electricity project has driven explosive growth in air-source heat pump heating machines with a high subsidy of 24,000 yuan per household. In 2017 alone, Beijing purchased more than 350,000 air-source heat pump heating machines, and total national sales exceeded 550,000 units. However, outside Beijing, Tianjin, and parts of Shanxi and Hebei, due to small subsidies or subsidies not being in place, the procurement volume of air-source heat pump heating machines was not ideal.

At present, coal-to-electricity in Beijing and Tianjin has entered the later stage, while coal-to-electricity in other provinces and cities will usher in an outbreak. It can be predicted that air heaters will welcome development opportunities and have broad market space. At present, Hebi City, Henan Province, has basically determined that in the 2018 rural "electricity replacing coal" program, all will use air heaters, with a renovation volume of 88,000 households. Miyun, Beijing, which has already undergone pilot projects, may all use heat pump air heaters for clean energy renovation.

In product technology, air heaters use vapor injection (or two-stage compression) compressors and can already achieve stable heating at an ambient temperature of -25°C. Moreover, because there is no water circuit system, they are more suitable for the northern market in some respects. In addition, in installation, the air heater system is simpler, installation is more convenient, and it has more advantages in schedule pressure.

At present, compressor manufacturers have launched compressors specifically for air heaters, and almost all industry complete-machine manufacturers are developing air heater products. At the 8th China Heat Pump Exhibition held in Shanghai on March 15-18, it has been confirmed that many companies will debut their heat pump air heaters for the first time. It can be foreseen that in 2018, air heaters will be a dark horse in the market.

Come to the China Heat Pump Exhibition to see heat pump air heaters

On March 15-17, 2018, the 8th Heat Pump Exhibition will be grandly held at the Shanghai Everbright Convention and Exhibition Center! The exhibition area will be nearly 55,000 square meters, with an estimated 350 exhibitors and an estimated 50,000 trade visitor person-times.

According to the pre-exhibition statistics of the organizing committee, many companies will debut their new heat pump air heater products at that time! Please come and visit!

Well-known exhibitors this year include A.O. Smith, Zhongyu, Midea, CLIVET, Shenbao, Alpuer, Zhongguang Outes, Ouke, Xinhu, Shenlan, Gaoyu, Hengyue, Zhengxu, Woyaan, Shengneng, Aoyimei, Grundfos, Baosheng, Bilai, Mitela, Paiwo, Xiandai Lai'en, Kelante, Zhongke Fude, Panasonic Wanbao, Shuangling, Nanfang Pump Industry, Hawei, Ruixing, Jiadifu, Keli, Guangteng, Longke Laifu, Gesimu, Halei, Minghuang Refrigeration, Haier, Highly, Chunyi, Bangpu, Aotai, Tongyi, Chuangneng, Huamu Chunqiu, Mango, Relifang, Oute, Santong, Shenshi, Bulu Refrigeration, Yatuo, Fengshen, Fenghuang, Yinghuate, Zhiboshi, Taida, Jubang, Phnix, Linuo Ritter, Haiwu, Aiwa, Shuangzhi, Meiken, Zhien, Ousidan, Aokelai, Stande, Huada, Kemao, Zhongka, Liansheng, Donglian Thermal Engineering, Kailu, Xinjia, Baode, Kaisite, Zhongde Haotai, Beilaite, Sujing Anfa, Defu, Zhixin Hongye, Yileikesi, Zhongli, Xingfeng, Yonghan, Sanhua, Pu'aidi, Bangdun, Peigao, Kejia, Zhongtian Huanke, Xihaimu, Quanneng, Tongchuang, Wankang, Simpson, Situ Huana, Highly Ruineng, Huatiancheng, Kangyuan, Nasen, Lvte, Guangmang, Zhenxin, Dunan, Keximan, Zhanpeng, Jutian, Mentemu, Lvzhou, Shuiyi, Sailuolin, Shanxinzi, Changfa Electric, Guoli, Jiuzhou, Zhongyou, Kexin, Fuli, Lailikeci, Honggu Refrigeration Machine, Sanglaisi, Yuqi, Jinmu, Yingtu, Hengrui, Haige, Changling, Yikenfeng, Gaoming Yili, Huibing, Meidibao, Jiumu Xiangneng, Xingbao Yuantong, Dingyi, Baolisi, Meizi Senmei, Huachuang, Boye, Tianda, Xiaohehe, Jielong, Baowen, Dahai, Mingri, Jiajia, Wangbang, Aoying, Xinlei, Kaijie, Tuoqiu Mingxin, Shixin, Yunming, Tongli, Xinju, Feierkesi, Zhuolong, Weiersike, Yitao, Hageno, Weiyi, Languan, Enfeite, Aoyuan, Huida, Xinna, Sanxin, Boen, Jinlun, Tianqi, Shuangfeng, Huatong, Gaolu Yangpu, Shunfeng Valve, Shufeng, Zhenlida, Rongzi, Xusheng, Shengsong, Junru, Nuobeite, Shengshi, Huijing, Dayang, Zongheng, Detian, Aokaili, Chengjiabao, Meiyao, Jindong, Xingbang, Chunyue, Demai, Jinli, Haisen, Yinuo, Ruiming, Dongcheng, Degema, Jia'enbei, Qiangrong, Zhongdu, Chuangyifeng, Sinuobao, Quansheng, Sangling, Meike, Zhengyang Tianxia, Zhengdi, Aosuolan, Gaodeng, Libang, Shang'erte, Wilo, Lihua, Jin Yongguang, Junhua, Tongyi, Wangkai, Jubang, Hualin, Jinhui, Boyuan, Jintuo, Huiquan, Reguan, Banke, Huahong, Tianpu, Huiquan Sunshine, Zhihai, Jianchun, Hongyuan, Yulu, Huipu, Weiken, Jingchuang, Jiuheng, Maineng High-Tech, and more than 300 companies.

(Sorted by booth number, as of January 30, 2018.)

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Copyright: Some content was first published in the March 2018 issue of Heat Pump Market magazine.

Thanks to Zhongshan Shenbao Electrical Appliances Manufacturing Co., Ltd. for accepting the interview and providing technical support.

For more heat pump air heater products, please visit the China Heat Pump Exhibition site.