Applied area of heat pumps

 In Japan, heat pumps for residential use have long been used in refrigerators and air-conditioners for cooling and heating, and now used at almost all households in Japan. In recent years, moreover, heat pumps are incorporated in water heaters and  clothes washing and drying machines, and they are rapidly coming into wide use as  their performance to save energy and reduce CO2 emissions and cost is highly evaluated.

 As is the case with homes, heat pumps are also used for space cooling and heating  in office buildings and shops as well as in refrigerators. Heat pumps are widely utilized for refrigerated display cases for sale of fresh food, and cooling and keeping warm of soft drinks in vending machines.

 On the city level, heat pumps are utilized for "district heating and cooling¨ to supply heat to multiple buildings and structures in a collective manner. Warm heat and cold heat for district heating and cooling is also produced by “combustion-based" equipment such as oil and gas boilers, waste heat from co-generation and the like. However, heat-pump-based equipment that utilizes various types of unused heat such as heat in the air, river water and sewage boasts much higher energy efficiency and much lower environmental loads compared with "combustion-based" equipment.

 In the industrial field, heat pumps are utilized in: cryogenic warehouse for frozen storage of fresh foods; the method to maintain the freshness of agricultural products with cold and humid air; the method to freely reproduce natural environment such as temperatures and humidity and efficiently cultivate various agricultural products; and the efficient heating method to drastically reduce boiler fuels by utilizing “vapor recompression” that compresses vapor that is usually thrown away and recycles the heat of the vapor.

 The most advanced semiconductor plants have clean rooms where highly efficient heat pump for business use are introduced to hold temperatures and humidity constant in all seasons around the year. Highly efficient inverter centrifugal chillers, which are capable of variable-speed operation and of which the part-load operation efficiency is dramatically improved, have been recently made available on the market, and there are many high-tech companies that have enhanced the competitiveness of their products as they succeeded in significant energy conservation and CO2 emission reductions by fully utilizing such centrifugal chiller.

 Moreover, warm heat in manufacturing plants was usually supplied by the steam produced by boilers in the past. As for such application, heat pumps have been also introduced because heat pumps are more efficient to meet the demand for heat at relatively low temperatures such as in the fields of hot water supply, warming and drying.

Various applications of heat pumps in proportion to scale and temperature
Various applications of heat pumps in proportion to scale and temperature

Heat pumps are also highly efficient for district heating and cooling in japan.
(Overall energy efficiency at each typical point: actual results in fiscal 2005)
Heat pumps are also highly efficient for district heating and cooling in japan.
(Overall energy efficiency at each typical point: actual results in fiscal 2005)

Specifically, the demand for hot water supply in production processes includes cleaning processes before car body painting (60℃ to 80℃), pipe cleaning processes in food factories (80℃ to 90℃), electric parts cleaning lines (40℃ to 50℃), and manufacturing processes in the pharmaceutical industry (80℃).
In all of these processes, hot water is now used by exchanging heat from steam to hot water. In some cases, the amount of steam consumed accounts for only about 26.6% of the amount of fuel consumed by boilers.
The areas where air-source heat can be used by heat pumps in place of such inefficient and high-CO2-emission pieces of equipment that burns fossil fuels include heating and hot water supply that account for most of the energy consumption in the commercial sectors, and heating and drying applications in the temperature range of lower than 100℃ in the industrial sector.

Plan to introduce heat pumps into production processes
Plan to introduce heat pumps into production processes

Example of heat balance of boiler
Example of heat balance of boiler

Heat recovery by heat pump from released water (warm water discharge)
Heat recovery by heat pump from released water (warm water discharge)

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