Low Carbon Buildings and Sustainability By Dr David Johnston – licensed under the Creative Commons Attribution – Non-Commercial – Share Alike License

LZC Technologies Space Heating - Low or Zero Carbon (LZC) technologies An office is to be provided with an underfloor space heating system. The annual space heating energy demand has been estimated from modelling studies and alternative heating systems are to be evaluated. The output capacity required (maximum) from any heating plant selected is 100 kW. Data Office space heating demand50,000 kWh/annum Data obtained from Building Regulations Part L2A (2006): Grid supplied electricity – CO 2 emission factor0.433 kg/kWh Natural gas – CO 2 emission factor0.194 kg/kWh Biomass – CO 2 emission factor0.025 kg/kWh Read the Powerpoint presentation ‘Energy resources & fuels’ before attempting this exercise.

LZC Technologies Option A Ground source heat pump (GSHP) - Coefficient of Performance (CoP) 3.5 Capital cost £800/kW output Electricity cost £0.09/kWh Option B Biomass boiler, thermal efficiency 60% Capital cost £350/kW output Fuel cost – wood pellets £0.04/kWh Option C Gas fired condensing boiler, thermal efficiency 95% Capital cost £90/kW output Gas cost £0.05/kWh Determine a)The CO 2 emissions (kg/annum) for each option. b)The % CO 2 emission savings from options A and B, relative to the gas condensing boiler. c)The capital costs of each option. d)The annual running costs of each option and comment on the likely payback implications from selection of options A or B.