Headline Results

● 2010 was on average the coldest year since 1986 and the winter period was the coldest since at least 1970;mean temperatures for January 2011 were somewhat below the 1971 to 2000 average, especially over parts of the UK, including Wales [2].

● The winter design temperature range for living rooms in the UK as recommended by the Chartered Institute of Building Services Engineers (CIBSE) is 22 to 23°C [3].

● Fig 5 illustrates that on almost every day of January 2011 the lounge interior air temperature exceeds 23°C & the highest temperature is 27.4°C (the green line). The lounge temperature is below the minimum comfort temperature of 18°C, on only two days. By contrast the exterior air temperature has a maximum and minimum of 10.3 °C and -6.3°C, which is a 16°C temperature range.

● The winter design temperature range for bedrooms in the UK is 17 to 19°C. Fig 5 illustrates (the red line) that on several occasions (15 in total) during January 2011 the interior air temperature in the bedroom exceeds 20°C and the highest temperature is 21.2°C. The bedroom temperature is below the minimum comfort temperature of 18°C on 15 days and the coldest temperature is 16.8°C.

● Because of the internal temperatures being well within recommended comfort ranges during a very cold January (by UK standards) it was anticipated that the power consumption, the associated energy costs and the CO2 emissions would be excessively high in relation to the usage of the EASHP. However, this is not the case as indicated by the results in Fig 5 (blue line just above the ‘0’ unit on the y axis, within the red band) it is almost negligible. The total power consumption for space and water heating for the EASHP was only 175.58kWh, a total monthly cost of £22.85 (unit cost of £0.13 per kWh) and only 95.73 Kg CO2e per unit emissions.