From Vernon Hockley
While Paul Younger is correct that ground source heat pumps do not work well with radiators designed for water at 70 °C (4 May, p 34), he has overlooked two things.
Much UK housing had its heating designed before adequate insulation became the norm. Once insulation is improved, radiators can work with water around 40 °C. Heat-pump systems also operate continuously, unlike traditional on/off radiator systems. Having installed a heat pump in a 1970s property, I can vouch for all this.
Great Barrow, Cheshire, UK
