Residential complex reduces gas use with CO2 heat pump

By Devin Yoshimoto, Nov 20, 2018, 14:35 4 minute reading

As gas prices in Australia continue to rise, so too does interest in CO2 heat pump technology – with local technology suppliers ready to meet that demand. Installing a CO2 heat pump at a residential complex in Melbourne is reducing hot water boiler gas consumption by 25-30%. Accelerate Australia & NZ reports.

COheat pump system installed by Melbourne-based Automatic Heating Global

In August 2018, Melbourne-based Automatic Heating Global commissioned a CO2 hot water heat pump at a residential apartment building in Melbourne's Central Business District (CBD).

The CBD installation is one of several CO2 heat pump projects the company has planned in the near future.

"This is one of several CO2 heat pump projects we currently have underway in Australia and New Zealand," Automatic Heating Global’s Business Development Manager Terry Plaisted told Accelerate Australia & NZ.

Interest in CO2 heat pumps, according to Automatic Heating Global, is being driven by recognition of their various benefits over traditional boiler technology, including: reduced dependence on fossil fuels, improved energy efficiency (especially in cold climates), and overall reduced environmental impact.

The CO2 heat pump was installed at Yarra's Edge Tower 1 (left) – a residential complex located in Melbourne's Central Business District in Australia.

Energy efficiency of heat pumps and CO2

Simply put, CO2 heat pumps supply hot water by employing the refrigeration cycle in reverse – extracting heat from either the ambient air, from the ground, or from another water source, and using it to heat and store water for use in a wide range of industrial, commercial and residential applications.

Heat pumps are significantly more efficient compared to conventional technology such as electric, gas or oil boilers.

Automatic Heating Global's CO2 heat pump boasts an average COP of 3.9, achieving close to four kilowatts of heating capacity for every kilowatt of energy input.

CO2 is also a vastly superior heat transfer substance compared to synthetic refrigerants, when operating in cold ambient temperatures, or when supplying high temperature water (~90°C).

These benefits were among the main messages communicated by Automatic Heating Global, Mitsubishi Heavy Industries and Mayekawa, who all exhibited CO2-based heat pump technology at this year's ARBS exhibition in May (see 'NatRefs buzzing in Australia at ARBS 2018', Accelerate Australia & NZ, winter 2018).

During a presentation made at ARBS, Automatic Heating Global’s business development manager, Lachlan Shemilt, explained how rising gas prices and an increasing focus on environmental sustainability in Australia initially pushed the company to investigate and invest in natural refrigerant-based heat pumps.

"It all started when we had some requests from customers for non-gas sites," said Shemilt.

"Though we're a supplier of heating equipment – predominantly gas-fired boilers – in Australia and New Zealand, we had some sites where it was non-gas and some requests from customers for non-gas applications and high water temperatures," he explained.

"Our extensive research led us to partner with a leading Japanese manufacturer, Nihon Itomic, which has a solid foundation and a long history in water heating innovation and technology. After testing some EcoCute CO2 heat pumps in our factory, we verified their exceptional performance and ideal application for high-temperature domestic hot water,” he said.

Shemilt explained that when the company did some initial return-on-investment calculations, the CO2 heat pump's performance advantages over LP gas boilers were very significant.

During the initial testing phase, Automatic Heating Global saw an "operating cost of about 75% less than an LP gas boiler," said Shemilt.

Demand for CO2 heat pumps has increased significantly this year, and we will no doubt see more and more inquiries in the future." 
– Terry Plaisted, Automatic Heating Global

Taking advantage of off-peak power

Fast-forward a couple of months later to July, and Plaisted explained that this CO2 heat pump installation in Melbourne was motivated by reducing dependence on fossil fuels, and by energy savings achieved through efficient hot water production.

"Our client had a need to replace their hot water system and was also looking for opportunities to reduce their gas consumption," said Plaisted.

At this particular Melbourne residential complex, the client decided to go with "a hybrid solution by using a combination of high efficiency gas boilers and a CO2 heat pump, after reviewing the savings demonstrated and seeing that a COP of 3.9 was available," Plaisted said.

"Up to 30% of the daily hot water load can be produced and stored at night during off peak times. This reduces CO2 emissions by running the heat pump instead of the gas boilers. We also expect to see a 25-30% reduction in gas consumption," he added.

Asked what Automatic Heating Global had learned from this installation, Plaisted says, "we established from this installation that the efficiency of domestic hot water systems can be increased by using a combination of modern gas condensing boilers and CO2 heat pumps".

In view of the ability of CO2 heat pump technology to deliver a number of environmental and economic advantages to developers, building managers and end users, the company is confident in the opportunities going forward.

"Demand for CO2 heat pumps has increased significantly this year, and we will no doubt see more and more inquiries in the future," said Plaisted.

This story appeared in the spring 2018 issue of Accelerate Australia & NZ.

By Devin Yoshimoto

Nov 20, 2018, 14:35

Related stories

Sign up to our Newsletter

Fill in the details below