Ecodan sustains good COP during last Winter’s prolonged cold spell
Monitoring of an installation of a Mitsubishi Electric Ecodan air-source heat pump in Hertfordshire has shown that it achieved an overall COP of 3.0 during December 2010, when the country faced long-periods of sub-zero temperatures. The trial shows that air-source heat pumps will work effectively under such harsh conditions and also highlights the importance of selecting radiators and heat emitters properly and ensuring that homeowners do know how to get the best from their system.
The installation is in a 1950s 4-bedroom house in Berkamsted, which is home to a family of four, including two children aged 15 and 12. High-tech Jaga radiators were fitted when the Ecodan system was installed in the Autumn of 2010, and the system has been monitored by Mitsubishi.
Jason Tinsley, technical manager for Ecodan, explains, ‘The key to these high efficiency levels is keeping the flow temperature around the system low. During December, the average flow temperature was only 33°C, yet the family remained perfectly warm.’ The average indoor temperature was around 20°C.
The Ecodan unit has an output of 8.5 kW and provides heating and hot water. It serves nine Jaga Strada DBE radiators. DBE stands for dynamic boost effect, which enables the room temperature to be increased quickly if necessary by providing maximum heat output from a radiator for about 15 minutes.
Radiators such as the Strada DBE offer maximum efficiency at low water temperatures and also contain only about 15% of the water normally held in a traditional radiator. There is therefore less water in the entire system, giving quicker response.
Jason Tinsley further explains, ‘Intelligent radiators like these use micro-processors to monitor the surrounding conditions in a way that traditional ones simply can’t. They will react to outdoor temperatures much more quickly, reducing the heat output if necessary or raising or lowering the flow temperature as required.’
