Case Studies

Shrewton Development - New Build

Ecodan air source heat pumps are ideal for use on new-build projects. The low running costs and excellent heating performance make Ecodan an attractive option for homeowners, housing associations and developers alike. Highfield Orchard in Shrewton, Wiltshire, consists of eight executive homes. The developer specified Ecodan to supply the space heating and hot water for a number of reasons.

As the site is off the gas grid, the developer originally considered oil. However, this was ruled out as both the installation and running costs were considerably higher than Ecodan. Highfield Orchard saw Ecodan as a highly cost effective solution for this development. All the properties have underfloor heating systems. These use lower flow temperatures than radiators and are a more efficient heat emitter. Underfloor heating helps to maximise the longterm energy and running costs savings available from Ecodan.

The Highfield Orchard site includes varying sizes of property, with heating loads between 5.2kW and 8.3kW. Ecodan heat pump uses the latest inverter technology to ensure that the system delivers exactly the right performance to match the load requirement of each property. That meant that the developer was able to specify the same system for every house, without the need to re-size or order different units.

Furthermore, Ecodan air source heat pump is supplied as a sealed system so it does not have to meet the new F-Gas Regulations. As a result the developer does not have to find specialist refrigerant handlers to install the equipment. Ecodan is straightforward to install, using normal plumbing skills. At Shrewton, Ecodan is linked to a BoilerMate Water Storage unit. This system designed for use with Ecodan includes pumps, valves and a specially designed control system to optimise the overall system efficiency.

Installers simply have to link the flow and return to the Boilermate and then to the central heating system as they would with a traditional condensing gas boiler.

For any housing developer, the real test of the technology is its popularity with buyers. Heat pumps have certainly met with approval at Highfield Orchard and the developer considered the Ecodan an excellent selling point: it is viewed as 'sustainable'; has low running costs; and also leaves extra space in the kitchen where a conventional boiler would normally be positioned. Perhaps most importantly, homeowners will notice very little difference in use between Ecodan and 'traditional' gas fired central heating - unlike some other sustainable heating systems. Even the user controls for Ecodan operate in the same way to those found on a traditional domestic heating system. Ecodan certainly makes it easier for homeowners to significantly reduce carbon emissions while cutting their energy bills.

Four Bedroom Refurbishment

A four bedroom house in Bedfordshire is the first home in the UK to benefit from the new, revolutionary Ecodan heat pump. As a result CO2 emissions from the home's heating system were reduced by 50% and the overall carbon emissions from the property by an impressive 34%.

The homeowner sought to reduce his carbon footprint and by installing Ecodan was able to do so, whilst at the same time, providing an ideal case study for the advanced heating system in operation.

Built in 2000, the four bedroom detached house has double glazed windows as well as loft and wall insulation. The existing heating system was previously run by an 80% efficient gas boiler providing 23.2kW of heat output from an input of 29kW. Based on the existing radiators it was calculated that the total heat output of the radiators was 13.4kW under standard boiler conditions with a flow temperature of 70ºC and the hot water demand of the home totals 140 litres per day.

Using the Ecodan air source heat pump, the heat load of the house was calculated to be 8kW. Operating at a flow temperature of 55ºC the heat output of the radiators will be 8.4kW, confirming that Ecodan is fully capable ofmeeting the heating demand of the house, using the existing radiators. In addition, one area of the house was changed to under floor heating.

The heat load of a house varies with ambient temperature. Traditional systems would vary the output from the radiators by turning them on and off frequently with Thermostatic Radiator Valves (TRV's), in order to meet the fluctuating demand.

As the ambient temperature increases, the heat load of the house decreases. The highly efficient Ecodan varies radiator heat output by changing the flow temperature, ensuring the highest level of COP possible. With average UK winter temperatures ranging between 2ºC and 7ºC, Ecodan operates at average flow temperatures between 35ºC and 45ºC providing the highest levels of energy efficiency.

When comparing the existing gas boiler to using Ecodan to provide domestic space heating andhot water, the reduction in CO2 emissions from the home are startling. The Ecodan with a seasonal COP of 3.4 emits 0.13kg of CO2 per kW of heat provided to the house, compared to the 80% efficient gas boiler, which emits 0.24kg of CO2.

This works out to 1,619kg of CO2 emitted per year when using Ecodan, as opposed to a massive 3,040kg of CO2 using the existing gas boiler. This clearly demonstrates a reduction of 50% with the help of Ecodan.

When taking into account this property's CO2 emissions, including that from lighting, appliances, space and water heating, the existing gas boiler accounted for 73% of the total CO2 emissions. This is dramatically reduced when using Ecodan, with the total CO2 emissions reduced by 34%.

The annual gas bill to operate the existing gas boiler was £560. The estimated electricity running costs of the Ecodan are £358, which represents a saving of £202 (36%) per year.

In the past there was an issue with the noise levels of air sourced heat pumps. The newly developed Ecodan however, offers one of the lowest possible nominal sound levels at 49dBA. External noise levels on the patio at the back of the house with the unit in operation were measured at 39dBA. This is very quiet when you consider that a modern computer has a noise rating of 37 to 39dBA, proving that sound levels are no longer an issue with the introduction of the advanced Ecodan system.