Warming water while cutting costs

The Q-ton consumes 76 per cent less energy than an electric heater and 46 per cent less energy than a gas boiler.

With high energy prices, manufacturers are searching for ways to cut costs. Manufacturers’ Monthly looks at Mitsubishi Heavy Industries’ Q-ton pump as a potential energy-efficient hot water solution.

Shene Estate, a 199-year old distillery located in Pontville, Tasmania, uses locally-sourced ingredients to produce gin and single-malt whiskeys, with products including the internationally-renowned and award-winning Poltergeist Gin.

To produce its gin and whisky products, the distillery uses traditional distilling methods using hot water to heat barley mash, which sees approximately 6,000 litres consumed every day, with multiple temperature changes required throughout the process. Starting at 90°C, the temperature is then reduced to between 64°C and 65°C, the optimum temperature to dissolve sugars contained within the starch of malted barley. Finally, towards the end of the process the temperature is brought back up to 70°C to dissolve enzymes within the mash.

Up until now, Shene Estate was using an instantaneous electric hot water heater to bring the water up to suitable temperatures. However, with ever-increasing electricity prices and with the distillery’s output continuing to grow – resulting in the need for higher and higher volumes of water being used each day – heating the water was becoming expensive and unsustainable for the business.

With the distillery having no connection to any gas grid, using gas for water heating was ruled out as an alternative and a more energy-efficient solution was sought out. Shene Estate’s owners turned to Mitsubishi Heavy Industries’ technical sales department, which took into account the distillery’s daily water volume and temperature requirements as well as the colder  temperatures the distillery operated in during Tasmanian winters, and eventually the Q-ton was installed.

Mitsubishi Heavy Industries’ (MHI) Q-ton, an air-to-water heat pump, uses CO2 as a natural refrigerant for the delivery of hot water. Drawing air through an evaporator containing CO2 refrigerant (which absorbs heat in the air), the Q-ton uses a high- pressure two-stage compressor to raise its temperature. The heat from the refrigerant is then used to generate hot water, which the Q-ton then stores in tanks.

The Q-ton can be configured as a stand-alone unit or operate with up to 16 units in modular configuration, providing 3,000 to 100,000 litres of sanitary hot water daily. The unit can be controlled from a touch screen that offers options for programmability and flexible operation not available with conventional hot water systems.

According to MHI, the Q-ton consumes 76 per cent less energy than an electric heater and 46 per cent less energy than a gas boiler, while at the same time generating 74 per cent less CO2 emissions than the former and 48 per cent less emissions than a gas boiler, making it both environmentally friendly and highly energy-efficient.

As the Q-ton can deliver at low outdoor temperatures down to -25°C, it was considered an optimal solution for Shene Estate and Distillery’s water heating operations. Because the Q-ton can achieve an industry leading co- efficient of performance (COP) of 4.3 by delivering 30kW of output power from only 7 kW input, this solution was much more energy efficient than the distillery’s old water heater, which was only achieving a COP of 1 (resulting in 48 kW output from 48 kW input).

Due to this energy efficiency,  the distillery found that the Q-ton is much cheaper to run: the company is anticipated to save 60 per cent per year on their energy bills compared to an instantaneous heater. Additionally, the Q-ton’s remote-control scheduling functions allows the distillery to produce hot water during off peak electricity periods and store this in tanks for later use, offering even further cost savings.

By working closely with the owners of the Shene Estate, MHI’s Q-ton was able to deliver a reliable hot water solution that significantly reduces the distillery’s energy costs, producing hot water via an environmentally-sustainable, energy-efficient method, even during Tasmania’s coldest months.