UK: The first UK installation of Carrier’s AquaForce 61XW heat pump using low GWP refrigerant R1234ze is providing cost-effective cooling and heating for one of the country’s leading vegetable producers.
The 1.2MW system is predicted to save the vegetable producer between £120,000 and £150,000 a year in heating costs and, with support from the Renewable Heat Incentive scheme, payback is anticipated within two to three years.
Previously, the company’s large cold store was cooled by a traditional air-cooled chiller with individual LPG boilers providing heating and hot water for the offices and 70 static caravans for seasonal workers. This system was said to be expensive to run and significant energy was being wasted through heat rejected by the chiller.
The company commissioned Stoke-on-Trent-based OMNI Heat and Power to design and install a more energy efficient and environmentally-responsible solution, based on low-carbon renewable energy and harnessing waste heat.
“The very wide temperature range, spanning -5ºC for the cold store to 55ºC for domestic hot water presented a particular challenge,” observed OMNI Heat and Power director Bradley Martin, noting that few heat pumps could cater for this while maintaining efficiency.
The solution uses the Carrier AquaForce 61XW heat pump to harness low-grade heat from ground loops buried in the soil, plus waste heat from the cold store refrigeration system. Hot water generated is piped to accommodation facilities and offices via a mini district heating system, providing comfort heating and DHW.
Power for the heat pump is provided by a large photovoltaic array on site. This supplies up to 1.5MW of electricity, making the facility almost totally self-sufficient in energy.
“We see huge potential for this solution in agriculture, where there is often a need for cooling for produce alongside heating for seasonal workers and offices. The Carrier system is unique in being able to cater for this diverse requirement,” said Bradley Martin.