Environmental and Economic Assessement

Environmental and Economic Assessment

Each COOL-PHASE system is predicted to save an average 800kg of CO₂ per annum Total overall CO₂ savings over a ten year period is estimated to be approximately 8 tonnes Within the first year of installation the COOL-PHASE system is predicted to provide an energy saving of approximately £185 By capturing 2.5kWh of latent energy per day during winter periods, this results in an additional energy saving of 225kWh per annum The Capital cost of a COOL-PHASE system is £135 per m² compared to £165 per m² for typical comfort cooling systems System Synopsis and Comparison It is estimated that an individual COOL-PHASE® passive ventilation system will consume 173 kWh of electricity per year, and that this electricity is consumed by 4 x 16 W fans operating for 4000 hrs per year with a load factor of 50% and 1000 hours under boost mode with a load factor of 75%. In additional the system will be used for cooling and heat recovery for 800 hours per year with 1 x 25 W pump with a load factor of 100%. Based on an equivalent 1.5kWh vapour-compression comfort cooling system which is used for 10 hours per day from Mid May through to September, the total energy consumption is estimated to be 1800kWh per annum. Heat Recovery It is estimated that through the pre-programmed winter control strategy, heat can be recovered during the late part of the occupied period and released back into the room the following morning. Based on capturing 2.5kWh of latent energy per day during winter periods of 90 days this results in a total energy saving of 225kWh per annum. Energy Savings Based on the energy useage detailed previously, the following energy savings are predicted :- Based on 10 pence per kWh of electricity use. 1.5kWh Vapour-compression Comfort Cooling system = 1800 kWh x 0.10 = £180.00 per system COOL-PHASE System = 173 kWh x 0.10 = £17.26 per system Therefore the energy saving per system is £162.74 per COOL-PHASE System However, when including the heat recovery available with the COOL-PHASE system, the actual running cost of the COOL-PHASE system is offset. 173 kWh less heat recovered of 225kWh = -52kWh x 0.10 = £-£5.24 per system Therefore the energy saving per system is £185.24 per COOL-PHASE System CO₂ Savings The Carbon Trust advise that 0.43kg CO₂ should be used per kWh of electricity use. 1.5kWh Vapour-compression Comfort Cooling system = 1800 kWh x 0.43= 774 kg CO₂ per System COOL-PHASE System = -52kWh x 0.43= -22 kg CO₂ per system Therefore the reduction in CO₂ is 796 kg CO₂ per Cool-phase System With a 10 year life expectancy prior to recharging the phase change material each COOL-PHASE system will save an average CO₂ of 796kg CO₂ per annum and approximately 8 tonnes of CO₂ per system over the 10 year period. The next stage… True zero carbon cooling and heat recovery From the outset, the COOL-PHASE system was designed to run on DC power, to benefit from Monodraught’s Sola-boost technology. Though only a small amount of power is required to run the COOL-PHASE system, it is still powered by mains electricity. Monodraught is currently in the development of a solar powered supply source, with the aim of creating a true carbon zero product, for both commercial and domestic markets.