Mitsubishi Electric - Heat Pump / Photovoltaic Case Studies

Air Source Heat Pump - Photovoltaic Case Studies

Air Source Heat Pump Performs Over The Worst Winter For Decades

A live trial of an Ecodan® air source heat pump in Hertfordshire has demonstrated that the system was still achieving over 300 percent efficiency levels (a COP of 3.0 – Coefficient of Performance) throughout the whole of December 2010, when the country faced long periods of sub-zero temperatures not seen for decades.

The trial has not only shown that air source heat pumps will work effectively in British homes under such harsh conditions, it also highlights the importance of sizing and selecting the radiators and heat emitters properly and ensuring that the homeowners know how to get the best out of the system.

The 1950’s, 4-bedroomed house in Berkhamsted, is the home of a family of four with two children aged 15 and 12.

The homeowner had new high- tech Jaga radiators fitted when the Ecodan system was installed in the autumn of 2010.

During December, while the whole country felt the full force of the harshest winter weather for decades, the family enjoyed an average indoor temperature of around 20°C, keeping them warm and comfortable throughout the entire Christmas period.

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 8.5kW Ecodan unit, which is installed in the alleyway of the house, provides all the heating and hot water that the family require. In addition to domestic hot water it feeds the nine radiators throughout the home.

With some manufacturers now claiming COPs of 4.0 or even 5.0 (5kW of heating from every 1kW of electrical energy consumed by the heat pump) Mitsubishi Electric is urging anyone considering a heat pump to remember that these COPs will typically have been measured in laboratory conditions at an outdoor temperature of 7°C (or higher) with the unit supplying a water flow at a temperature of 35°C, or even lower.

Church taps into power from above

When the parishioners of one of the UK’s finest Anglo Saxon churches were looking at how to make their place of worship more environmentally friendly, they took inspiration from BBC’s Songs of Praise, which in 2010, featured St Denys Church in Sleaford, Lincolnshire, which had fitted solar Photovoltaic (PV) power generating panels.

Now, after a £50,000 investment, the congregation at All Saints Church, Wing with Grove in Buckinghamshire has not only reduced the building’s carbon footprint significantly but also found a way of generating an income for decades to come.

The congregation originally wanted to find ways of supporting the Church of England’s national environmental campaign called Shrinking the Footprint. In light of the current global climate change crisis, they felt that in addition to praying at services for Christians to look after God’s creation, the Church should take action to reduce its carbon footprint.

After visiting St Denys Church in Sleaford to find out more about PV systems, former church warden Martin Findlay realised that all churches face east and are therefore likely to have south-facing roofs, which are ideal for solar installations.

The array of 54 PV panels from Mitsubishi Electric has been carefully installed on the nave and south aisle roofs and cleverly hidden from view behind the church’s parapet.

The 6.29kW system will enable the Church to benefit from an annual income of around £3,000 under the government’s Feed-In tariff (FIT), which sees energy suppliers making regular payments to householders and communities who generate their own electricity from renewable or low carbon sources.

All Saints is not only able to reduce the amount of electricity it consumes, it will also be able to sell the excess energy it produces to the National Grid.

The Parish County Council began a feasibility study into the scheme and then began to raise funds amongst the local community. They also had to get a ‘faculty’ (special permission from the Diocese to carry out the work), and planning permission from Aylesbury Vale District Council.

The hard work by the parishioners and the congregation has paid off and they are delighted with the income that will now be generated for the Church.