Domestic heat pumps are increasingly popular with home owners but the biggest commercial heat pumps are thousands of times more powerful, capable of serving 27,000 households.
Heat pumps require electricity to work but can produce around three or four kilowatts of heat for every kilowatt of power they consume, making them highly efficient, and are recognised as part of the solution of weaning us all off fossil fuels. But there is now an 'exploding' demand for giant heat pumps.
To give you an idea of what these giant machines are capable of, let's take and Olympic sized swimming pool that holds 2.5 million litres of water (550,000 gallons). If for some reason you wanted to bring it from a pleasant 20C to boiling point, German firm MAN Energy Solutions (MAN ES) has a heat pump that could do it. "We can do this in less than four hours," explains Raymond Decorvet, who works in business development at MAN ES. "Or we could freeze the whole thing in about 11 hours."
MAN ES's biggest commercial heat pump has a total heating capacity of 48 megawatts (MW).
It can produce temperatures of up to 150C and heat thousands of homes, not just one. The company recently installed two of these machines in the port city of Esbjerg, in Denmark.
In this installation, the heat pumps' CO2 refrigerant will absorb a small amount of heat from seawater. Compressors boost the temperature of the CO2 and the system can then transfer this heat, providing water of up to 90C to a district heating system serving 27,000 households.
"The demand for district heating is exploding," says Mr Decorvet. An urgency to move away from fossil fuels is leading to a rush - particularly in Europe - for bigger and beefier heat pump systems that can power entire towns.