Fan-convector radiators provide the key to heat pump replacing an oil-fired boiler
When an off-gas farmhouse in rural Norfolk needed a new heating system, the owner and tenant agreed that energy-efficient low-carbon warmth was the way forward, rather than simply replace the oil-fired boiler. A straightforward retrofit solution was provided by a Dimplex air-source heat pump and SmartRad fan-convector radiators. The 4-bedroom home was built in the late 1980s and previously used an oil-fired boiler with a wet central-heating system. A combination of rising fuel prices and increasingly erratic heating performance prompted the change.
Dimplex’s SmartRad range has been designed as a cost-effective, responsive and energy-efficient alternative to underfloor heating or conventional radiators for heat-pump systems. Flow temperatures can be as low as 40°C to maximise heat-pump COP.
An 11 kW air-source heat pump against the back wall of the house could take advantage of the existing central-heating pipework. The 11 SmartRad fan convectors are sized so the fans operate at their slowest speed under normal conditions. Once the house is up to temperature, natural convection through the heat exchanger means that the fan does not need to run at all.
Installation is reported to have been straightforward, even though existing pipework embedded in the floor screed was variously 12 and 15 mm. The fan convectors were connected using push-fit connectors.
The water content of these fan convectors is only 5% that of a typical wet radiator, so they respond quickly.
Tenant David Miller particularly notices the fast response when the front door is opened: ‘On a cold day, if someone comes to the front door, the SmartRad in the hall gives a fan-assisted boost of warmth within 10 seconds of the door being opened. It really is that fast.’
