Dorin: CO2 'the refrigerant of the future'

Dorin: CO2 the refrigerant of the future

New components are helping to bring CO2 refrigeration systems to warmer climates and heat pumps can broaden the application of this natural refrigerant still further, Giovanni Dorin, the company’s marketing director, told.

Asked whether he sees CO2 as the refrigerant of the future, Dorin did not hesitate: “Absolutely!” Thanks to new developments in compressor and ejector technology, “CO2 systems are gaining more and more latitude […] in terms of allowing the use of CO2 transcritical systems in higher ambient temperatures,” he said.

Communicating this message to customers is crucial. “We show our customers how to handle our compressors and invite technicians to train on Dorin’s premises,” he said.

In the context of the global HFC phase-down agreed in Kigali last week, chemical companies are pushing synthetic refrigerants – so-called HFOs – as part of the solution. Indeed, Dorin makes compressors that are ready to work with these HFO refrigerants. So as a component manufacturer, what stance does the company take here?

“We have to observe what’s happening in the market, but we don’t always have to follow,” said Dorin. “We don’t have to leave the decision in the hands of others.”

“We have to take a position and tell our customers what we think. We say that CO2 […] is the real solution,” he said – alongside hydrocarbons and ammonia for certain applications. HFOs, meanwhile, are little more than “a temporary alternative” to natural refrigerants.

CO2 heat pumps ripe for growth

Supermarkets are today the largest area of application for CO2 technology, particularly large racks or smaller condensing units. But Dorin sees heat pumps playing a larger role in future. “[They] are becoming more interesting – to provide heating, cooling and hot water not just for residential but also for commercial and industrial applications,” he said.

He sees increased interest in heat pumps as a reflection of the growing trend towards providing integrated heating and cooling solutions.

The Italian manufacturer was in Nuremburg to showcase two new CO2 compressor series – the CD400 and CD500 ranges for large refrigeration racks in applications such as food processing, warehouses and other industrial sectors.

“The final aim of all these compressors is to reduce energy consumption, to help reduce costs. Using an inverters, we’ve created a speed variation model for our compressors to help manufacturers to manage the energy consumption of the system itself,” said Dorin.

To complement this, the company’s compressor management model (CMM) allows users to monitor compressor activity on site or remotely. “Refrigeration is going towards smart technology. You can’t put much electronic technology inside the compressor itself. You put the electronics alongside it. The main thing is to create a system that can control and manage the compressors,” Dorin said.

It has also developed a high-efficiency transcritical CO2 compressor for optimised for use with heat pumps. With CO2 heat pumps, the presence of high temperature fluids in the gas cooler inlet can reduce cooling capacity – not to mention efficiency.

The CDHP2500 is a 4-cylinder transcritical compressor developed for a 50 kW air-to-water heat pump that produces hot water at high temperature. Developed in the context of the EU-funded NxtHPG project on natural refrigerant-based heat pumps, the heat pump replaces the traditional gas boiler in feeding hot water to radiators.

Test results showed that in ambient temperatures of -10 to +35°C, the cycle produces hot water at 80°C – ideal for heating – and water at 40°C, ideal for domestic use.

Dorin will offer a dedicated range of eight 4-cylinder models for use in heat pumps, at pressures of 100-150 bar and with a heating capacity of 40-110 kW.