Fujitsu air conditioning entered the market of heat pump type hot water heating system in Europe now since 2009. In order to further strengthen the business of the heat pump type hot water heating system, we developed the new model of “WATERSTAGE®” with enhanced heating performance at the outdoor temperature -25°C and expanded the product line up. The low outdoor temperature type will be released early in October.
The hot water heating system is an appliance to heat the room by passing the hot water heated by heat source through the pipe installed in the wall and floor. In Europe, the system to make hot water by burning gas or kerosene is commonly adopted but recently, energy-efficient heat pump type which does not emit CO2 is attracting attention as state-of-the-art technology to restrain the global warming. However, the conventional heat pump type hot water heating system had disadvantage that it can not retain the high hot water temperature and the heating capacity drops under the low outdoor temperature.
The low outdoor temperature compatible type developed this time made it possible to provide hot water of 60°C at low outdoor temperature of -20°C and hot water of 50°C at -25°C by “Linear control injection refrigeration cycle” (*1).
Furthermore, we have achieved the industry's top class(*2) COP(*3) 4.40 by enhancing the energy-saving performance adopting the “high response control” which optimizes the refrigeration cycle corresponding to the operating characteristics of the heat pump type hot water heating system. Thereby, the efficient hot water heating at the low outdoor temperature has been realized.
By adding the new product to the lineup, our company will aim to expand the air conditioning business in various countries in Europe together with air conditioners.
The conventional models are based on the specifications that the upper limit of highest hot water temperature is 50°C and have been sold mainly for newly built houses with high heat insulation efficiency as heat source appliance for low temperature panel heater and floor heating.
However, in order to cope with wide range of needs such as for already built houses with low heat insulation efficiency and cold district, the products which exert high performance under the condition of low outdoor temperature have been demanded.
Key Product features:
1. Realizing high hot water temperature at low outdoor temperature by adopting “linear control injection refrigeration cycle”
In the conventional refrigeration cycle which is commonly adopted, when hot water temperature was made higher, the compressor tended to be overheated and cause machine failure. Therefore, the overheating was suppressed by restraining the capacity of compressor, which caused the problem that the hot water temperature dropped due to the lack of capacity when outdoor temperature dropped.
The “linear control injection refrigeration cycle” realized the high hot water temperature by suppressing the overheating of compressor by cooling the compressor directly with refrigerant (liquid injection cooling) and enhancing the capacity at the low outdoor temperature.
This refrigeration cycle made it possible to provide hot water of 60°C at the outdoor temperature -20°C and hot water of 50°C at -25°C. Compressor for “linear control injection refrigeration cycle”
2. Enhancing energy-saving performance by “high response control” adopting twin sensor. By two sensors (twin sensor), it has become possible to control the refrigeration cycle condition in more detail than conventional models and make waste-free operation corresponding to the heating load.
Thereby, we have achieved the industry's top class(*2) COP(*3) 4.40 and enhanced the energy-saving performance in the actual use.