1. Low Carbon Buildings and Sustainability By Dr David Johnston – licensed under the Creative Commons Attribution – Non-Commercial – Share Alike License http://creativecommons.org/licenses/by-nc-sa/2.5/

2. Space Heating LZC technologies a) CO 2 emissions (kg/annum) for each LZC technology Energy used = space heating demand / thermal efficiency or COP CO 2 emission = electricity energy used x CO2 emission factor Option A GSHP Electricity energy used = 50000/3.5= 14286 kWh CO 2 emission= 14286 x 0 433= 6186 kg/annum Option B Biomass Thermal energy used= 50000/0.6= 83333 kWh CO 2 emission= 83333 x 0.025= 2083 kg/annum Option C Gas Thermal energy used= 50000/0.95= 52632 kWh CO 2 emission= 52632 x 0.194= 10210 kg/annum LZC Technologies - Answers Space heating demand CoP of heat pump Efficiency of bomass boiler Efficiency of condensing boiler CO 2 emission factor

3. LZC Technologies - Answers Space Heating LZC technologies b) % CO 2 emission savings for A and B A GSHP % CO 2 emission saving= (10210-6186)/10210 x 100= 39.4% B Biomass % CO 2 emission saving= (10210-2083)/10210 x 100= 79.6% c) Capital costs of each option Capital cost = cost per output x output capacity Option A GSHP Capital cost= £800 x 100= £80000 Option B Biomass Capital cost= £350 x 100= £35000 Option C Gas Capital cost= £90 x 100= £9000 Gas CO 2 emissions

4. LZC Technologies - Answers Space Heating LZC technologies d) Annual running costs of each option Running costs = electricity energy used x electricity cost Option A GSHP Running cost= 14286 x £0.09= £1286/annum Option B Biomass Running cost= 83333 x £0.04= £3333/annum Option C Gas Running cost= 52632 x £0.05= £2632/annum Conclusion It would not be possible at present to justify options A and B on payback period alone. Options A and B may be required in order to secure Building Regulations Part L planning approval. Electricity cost Gas cost Wood pellet cost Electricity energy used