When an off-gas farmhouse in rural Norfolk needed a new heating system, owner and tenant agreed that energy efficient low carbon warmth was the way forward, rather than a replacement oil-fired boiler. And Dimplex SmartRad® fan convector radiators with a Dimplex air source heat pump offered a straightforward retrofit solution.
The four-bedroom home, built in the late 1980s, had used an oil boiler to power a wet central heating system, but a combination of rising fuel prices and increasingly erratic heating performance as the boiler aged prompted the decision to switch to renewable energy with SmartRad heaters.
Occupier David Miller explains: “The owner of the property and I share an interest in energy issues. We agreed that we wanted long term sustainability as well as increased independence from rising fossil fuel prices and were both already familiar with heat pumps. Once we heard about SmartRad, it was the obvious system to choose.”
Heat pumps are one of the most efficient forms of domestic heating available. Air source units, in particular, are ideal for retrofits, as they require no ground collectors to be installed. The SmartRad range has been designed as a cost effective, responsive and energy efficient alternative to underfloor heating or conventional radiators for heat pump systems. Using flow temperatures as low as 40°C, the heaters allow heat pump CoP to be optimised to reduce running costs and CO2 emissions.
At the farmhouse, the first step was to specify and install an 11 kW Dimplex air source heat pump against the back wall of the property where it was able to take advantage of the existing central heating pipework. 11 SmartRad fan convectors were specified for the property, with the heaters sized so the fans operate at the lowest setting under normal conditions. In fact, once the house is up to temperature, for much of the time the trickle of heat rising from the natural convection through the heat exchanger means the fan doesn’t run at all.
As a rule of thumb, halving the flow temperature of a central heating system, to ensure maximum efficiency for the heat pump, requires radiators around four times larger to generate the same heat. But the SmartRad range offers an ideal alternative; due to their advanced performance, these heaters can be sized to be smaller than the conventional radiator they replace.
Installation was straightforward, even though the existing pipework, embedded in the floor screed, was variously 12mm and 15mm; push fit connectors made it simple to adapt the SmartRad on to both. With a choice of left- or right-hand, or invisible ‘through the wall’ plumbing connections, the design makes it easy to fit a system around existing infrastructure.
Installer Bill Rodger of NFSE Ltd describes the installation. “The SmartRad heaters were easier to install than a conventional radiator, very simple to put in, even retrofitting to the existing system – the push fit connectors made it straightforward. Because they’re a low temperature system, they need a high flow rate to work well, but this was easily achieved, as they contain only five percent of the water of a typical wet radiator; plus, this also meant they were smaller and lighter to install.”
David Miller finds the SmartRad heaters very comfortable to live with, primarily because they are so responsive. “The house is now noticeably warmer within 15 minutes of switching on the heating. And 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.”
The SmartRad range is available in four sizes, with nominal outputs ranging from 0.8kW to 1.8kW. However, with the flexibility of significant output variations based on fan speed and water flow temperature, the range spans applications from 0.4kW to 5kW.
Dimplex Tel: 0845 601 5111 Fax: 01489 773061
email: marketing@dimplex.co.uk or www.dimplex.co.uk
