Researchers in Italy have designed a novel carbon dioxide heat pump that can work with photovoltaic-thermal energy, a finned coil heat exchanger and a U-tube borehole heat exchanger. Their experiment ...

The pipes may be laid either as a series of coils or 'slinkies' in shallow trenches ... The warmed brine circulates back to the heat pump, where a compressor increases its temperature. A heat ...

Something useful to know is what a heat exchanger is. It’s a coil of pipe over which hot ... Manufactured by German boiler giant Viessmann, it’s rated consistently highly and was the Which?