Thames provides source for sustainable energy through heat pump

A waterside property in Marlow, Buckinghamshire, has been fitted with a heat pump system from Danfoss Heat Pumps UK, which generates its energy from the River Thames. Mike and Doris Tucker had owned the character stone-built property for seven years and now, in retirement, decided to investigate ways to make the home more energy efficient and sustainable. This included replacement double glazing, improved loft insulation and a high efficiency heat pump.

Tucker, a qualified engineer, previously used LPG gas, as the property is not on mains gas. Over the past two years, with significant LPG price increases, set to continue  into the future, he decided it was time to act.  He found heat pump installer Geothermique during an internet research on heat pumps and local installers, and was impressed when they came  to survey his property, the resulting survey results and savings projections.

Having worked with Danfoss products before Tucker said he was aware of their quality, and researched a range of different heat pumps to find the best solution finally opting for a water source heat pump. He admits to taking a “leap of faith” to replace his existing gas system with something far more sustainable and energy efficient, from a smaller specialist company, but is well satisfied with the result.

According to Tucker: “Robert Carter of Geothermique really seemed to know what he was talking about. He set about making plans for a water source heat pump and, even though this type of installation is quite rare, he was really positive about the energy savings we would be able to make in the future.”

Geothermique, a specialist installation company designed a heating system using a Danfoss 12 Opti Heat Pump, with heat supplied from a river water collection sump adjacent to the Thames, using a submersible pump half a metre below the water table to supply a  heat exchanger in an adjacent boathouse, three metres away. From there an underground ‘brine’ circuit conveys the warm water 30 metres to the house.

Robert Carter from Geothermique explained: “We looked at the different options and this proved to be the most cost effective in terms of performance.  The river water in this area has a consistently high temperature and means that it optimises the running of the heat pump.  This is the first time we have installed a water source heat pump system, but the installation went very smoothly and we are confident that the couple will reap the benefits for many years to come.”

A 12 kW heat pump was specified for the three bedroom property, with space heating supplied through the already installed, over sized, radiators. The heat pump also supplying the home’s hot water needs. Geothermique removed the existing old LPG boiler and hot water tank in the utility room and replacing it with the latest highly efficient Danfoss Heat Pump, within a few days. This takes up less space whilst provided full heating and  hot water requirements, including a booster immersion heater should the need arise.

Tucker said: “Geothermique explained that heat pumps are designed to provide lots of continuing ‘low grade’ heat, rather than the short bursts of high energy from  fossil fuels.  This is more energy efficient and means that we are benefit from much lower running costs in the future. Since its installation, all our heating demands are being met for less than 50p per day. To date, we have had little space heating demand, but when there was a call for it, it was met efficiently. I was intrigued to find that, with no room thermostat or time switch, I felt out of control initially, but slowly came to the realisation that the comprehensive Danfoss control system was in control, with very satisfactory results.

“Geothermique worked closely with us to create a sustainable solution, less reliance on fossil fuels and a much lower carbon footprint.  Rob had some hand holding to do during the cutover period, period, but was proved right. Aside from significantly lower bills, my wife’s great pleasure was to see the 1200litre LPG tank disappearing off site!”

Chris Dale from Danfoss Heat Pumps, said: “Water source installation is still quite rare in the UK, but it is proving to be one of the most efficient ways of sourcing heat for a property.  This method of heat collection offers a high coefficient of performance, which means great energy savings and a very natural and sustainable way to provide heating and hot water for a property.”

Closed loop water source heat pumps are a tried and tested method in Scandinavia and other Northern European countries, where there are many properties located close to water.