Unsolicited testimonials are rare but NIBE Energy Systems received just such an accolade during a broadcast by BBC Radio Orkney. In 2006 the Orkney Housing Association commissioned 32 domestic units to be built in Stromness to accommodate the expanding demand for affordable housing there. The 2, 4, 5 and 6 person homes were of prefabricated wooden A-frame design, clad in Siberian Larch and with a high degree of insulation against extremes of climate common in the far North. To source the underfloor heating system and all hot water requirements, each house had a NIBE Fighter 360P Exhaust Air Unit, a heat pump working on the recovery of energy that would otherwise be lost in the normal ventilation process.
The interviewer asked Jimmy Johnston, a resident in one of the OHA homes, how he was enjoying his new house and whether the energy saving features in it were really reflected in affordable electricity bills. Jimmy could hardly have been more enthusiastic, saying that the whole family had a warm home and an abundance of hot water on tap at all times. He is on metered electricity and clearly suprised the interviewer when he said that the bill in his all-electric house averages around £7 per week and did not exceed £10 a week even in the depths of winter. When asked if the family made special efforts at energy conservations - turning off lights and keeping the heating low - Jimmy's response was that at that cost, they did not need to make special efforts. He said that as far as he was concerned air source heating such as his NIBE system was definately the way forward and that his neighbours all felt the same.
The NIBE Exhaust system is very simple. The heated air that would normally be expelled into the outside atmosphere is taken from the top of the house and passed through the Fighter 360P heat pump. This acts rather like a refrigerator in reverse compressing the warm air to maximise energy for input to the double-jacket hot water tank, and the process is so efficient that the exhaust air is eventually released into the atmosphere at a temperature very close to zero degrees Centigrade. There is an immersion heater in the tank that will provide back-up at times of peak demand or extreme low outside temperature but for the most part the heat pump does the work. As Jimmy Johnston's electricity bill shows, the proof of the pudding is in the heating.