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Keywords

Y2

deviceZ4

electricity

S5

renewable energy

LTechnical Services

Heat Pump & Thermal Storage Technology Center of Japan

Commercial Heat Pump Water HeaterFeatures
S Heat pump water heater is highly efficient system that heats water by using heating energy, which may not be very
hot but has energy abundantly available, such as ambient heat, underground heat or waste heat with the usage ofheat pump technologies.
• A new hot water system to replace the conventional
boilers.
• Only 1/3 (this may fluctuate depending on the heatsource temperature and other various conditions) ofthe energy required to produce the same amount ofwater.
• Some models can store hot water at 90˚C, even froma heat source with an external air temperature of-25˚C.
S Wide range of variations• The introduction of the commercial Eco-Cute, whichuses natural refrigerant CO2, is increasing.
• A wide range of products are available from compact
models, equivalent to home use, to larger models,
used for pools and spas.
• Hybrid hot water supply systems that combine
combustion type boilers are also possible.
S Reduction of the energy consumption and CO2 is possible, and the electric power load leveling and optimization arealso possible.
• Due to the high energy efficiency the energy consumption is low. Compared to fossil fuel combustion system it isvery energy conservation system which also can significantly reduce CO2 emissions.
• The use of hot water stored in the hot water storage tank makes it possible to level the load by suspending theoperation of the heat source during the day and storing hot water at night, and to respond to optimization for
operation during the day when the amount of power generated by renewable energy is high.

Basic Concept or Summary
S Refer to pages, such as R-03 (Heat Pump [General purpose]) and R-04 (Air/Heat Pump Water Heater with
Natural-Refrigerant), regarding the operating principles of the heat pump water heater.
S Types and characteristics of refrigerants for heat pump water heater(1) Natural refrigerant (CO2)• Environmentally considerate refrigerants that have an Ozone Depletion Potential (ODP) of 0 and a Global
Warming Potential (GWP) of 1.
• Hot water storage tanks can be made smaller, since a maximum hot water output temperature of 90˚C ispossible. Furthermore, applications that require high temperature hot water, such as dish washers in kitchens,
can also be provided.
• Many models adopt a single pass temperature rise system that increases the temperature of the feed-water up
to high degree in one rush. (Some models support circulated heating also)(2) HFC refrigerant• There are two types of heating systems, one raises the temperature while circulating water with a constanttemperature difference (about 5˚C), whereas the other comprises a single pass temperature raising system.
• Although technically it is possible to dispense hot water at a high temperature of 90˚C, using the HFC
refrigerant, but doing so significantly reduces the efficiency and for this reason the characteristics of therefrigerant are generally utilized with many models set to 70˚C, the maximum temperature for highly efficientoperations.
• Since many parts are in common with other heat pump equipment, such as air conditioners, the products canbe delivered with a high degree of reliability at a relatively low cost.
S Types and characteristics of hot water storage tanks(1) Sealed tanks• These tanks are made of SUS. Hot water can be supplied using service water pressure, since it is possible toconnect the tank to the service water system. Since the application of a load can potentially cause damage,
hot water supplies to lower floors are restricted.
(2) Open tanks• Many of these are panel tanks built on site, using SUS or FRP. The internal pressure of a tank is atmospheric
and a pump for supplying the hot water is required separately, however, it supports an instantaneous supply oflarge quantities of hot water or the supply of hot water to the lower floors with piping over a long distance.

Effects or Remarks［Efficiency]

S Trends in Commercial Heat Pump Water
Heater Efficiency
With efficiency improvements fromtechnological developments by domestic
manufacturers, an annual average heating
efficiency of 4.2 has been achieved.

Trends in Commercial Heat Pump Water Heater Efficiency

4.5
4.4
4.3
4.2
4.1

4
3.9
3.8
3.7
3.6

COP =

Available thermal energy (kW)Input energy (kW)Annual Heating Efficiency =3.52000

2005

2010

Intermediate COP

20152020 ［FY]Annual Heating Efficiency

Annual Heating Amount(Annual Standard Reserved Hot Water Thermal Dose)Annual Electricity Consumption Amount(Annual Power Consumption for Standard Reserved Hot Water Heating

S Commercial Heat Pump Water Heater – Introduction of Case Study
1) Location: Ishikawa Prefecture 2) Industry: Hospital 3) Scale: No. of Beds - 1994) Hot Water Equipment: Commercial EcoCute (Hot Water Tank 32 m3) 30kW x 8 units
Effect of Introduction:
As a result of renovating the above facility to fit the hot water supply system with a heat pump water heater(Commercial EcoCute) instead of a kerosene boiler, primary energy consumption has been reduced by about
31%.

Commercial EcoCute

External appearance of Building

Primary Energy Consumption Reduction Effect
AdoptedSystem

Commercial EcoCute x 8 units

Conventional
SystemKerosene Boiler

Reduction

Specs: Annual simulated comparison under same load conditions
Primary energy equivalent※Electricity (Whole Day) 9.76MJ/kWh *Kerosene 36.7MJ/ℓ*”Act on the Rational Use of Energy Enforcement Regulations” (RevisedMarch 1, 2016)

EcoCute Hot Water Tank

Contact:

Heat Pump & Thermal Storage Technology Center of Japan
International & Technical Research Department
Address: 6F, Hulic Kakigaracho Building, 1-28-5 Nihonbashi-Kakigaracho, Chuo-ku, Tokyo.
Tel: +81-3-5643-2404
Fax: +81-3-5641-4501
URL: http://www.hptcj.or.jp

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