Financial Calculations

Boiler Efficiency Improvements

The boiler is inefficient compared to current standards. The calculation below quantifies the saving that could be made with a modern replacement.

Estimated gas consumption for central heating and hot water 12702kWh
Estimated Pilot Light Gas Consumption 1839kWh
Gas consumption for Heating and Hot Water 10863kWh
Approximate Current Boiler Efficiency 70%
Heat Used on central heating and Hot Water 10839 x 0.7 = 7587.3
Approximate Replacement Boiler Efficiency 90%
Fuel requirement with replacement boiler 7587.3 / 0.9 = 8430.3
Fuel Saving  10863 - 8430 + 1839 = 4272
With gas at 0.04p/kWh the annual cost saving would be 4272 x 0.04 = £170.88

Use of Insulated Radiator Panels

 Location WallOutput  % Total Output
Dining Room Inside3109 26
Living Room 0 0
Kitchen Inside1749 15
Reception Outside1749 15
Toilet Outside469 4
Front Bed (Main)  Outside1289 11
Front Bed (Small)  Outside932  8
Bathroom  Outside1554  13
Back Bed  Outside1140  10
 TOTAL  11991

 


Insulated panel manufacturers claim as high as 27% savings. However, for the project house a more modest 10% will be used.

 Percentage of radiator heat output on outside walls 60%
 Annual Heat Energy used for central heating 9188 kWh
 Heat dissipated through radiators on outside walls 9188 x 0.6 = 5512.8 kWh
 Saving at 10% 551 kWh
 With gas at 0.04p/kWh the annual cost saving would be £22