Eco Cute - EcoCute Machine Basics

EcoCute Machine Basics

An EcoCute machine or system consists of a heat pump and hot water storage unit. The components are serially concatenated with sealing refrigerant CO₂ gas in circulation.

1. At the first stage, a heat exchanger collects heat from the air outside to use as energy for the refrigerant. Air flow is usually obtained using a centrifugal fan; in cold areas with ambient temperatures around -20 to -25 ℃ an auxiliary fan heater is attached.
2. A gas compressor is used to heat the gas CO₂ refrigerant to around 100℃ under pressure of 10MPa via adiabatic compression. The carbon dioxide becomes a supercritical fluid. Several types of compressor can be used, including dual layer cylindrical compressors, scroll compressors, and dual stage rotary compressors
3. At the second stage a heat exchanger transfers energy from the hot refrigerant into water to produce hot water. Water temperatures around 5℃ and up are suitable at this stage.
4. Finally, ejector or expansion valves reduce pressure on the refrigerant, letting it cool via adiabatic expansion and revert to CO₂ gas.

The EcoCute derives two units of energy from ambient air temperature for every unit of electrical power it requires. Each of these produces more than three units of hot water energy, resulting in reduced CO₂ emissions compared to water heating via electricity or natural gas. To produce 90℃ hot water, an EcoCute consumes 66% less energy than an electric water heater, and costs 80% less than heating water via natural gas in Japan. Also, by reducing use of fossil fuels, the EcoCute results in more than 50% reductions in CO₂ emissions

The EcoCute's COP is 3.8 in industrial use, while electric power water heating is 1.0, and gas boiler is 0.88 including pilot light loss.