Carbon
Dioxide Pollution figures for various fuels
See assumptions below.
Running cost for various heating methods
Updated June 2008.
Notes and assumptions.
It is now quite difficult to compare fuel prices
due to 2-tier pricing. Furthermore, prices are
presently changing. Please check your local
supplier.
Oil cost 55p/ litre.( 2008), LPG, 39p/ lit.
Electricity 12.5p/unit
Gas condensing boiler efficiency 90%
Oil boiler efficiency 85%
LPG condensing boiler efficiency 88%
Electricity 100% efficient at point of use. Off peak 85% at point of use. (Note, the efficiency for off-peak heating is less than 100% since unnecessarily high temperatures at night are inevitable. This varies from 60% in a badly insulated house to 95% in a super-insulated house.)
The COP (coefficient of performance) of a heat pump is the ratio of input to output.
Variation in efficiency with heated water temperature.
You MUST understand this graph, please have a good look.
The above graph shows how important it is to keep the heated water temperature as low as possible. To attain a COP of 4, it is necessary to keep the heated water down to 35°C. This is only possible with a good underfloor heating system. If radiators are used, then they must be oversized to keep the temperature down as far as possible.
The red line shows how much the efficiency improves if spring water is used. Unfortunately, this is not commonly available.
The difference between the two lines demonstrated how important it is to have a large ground collector area that will keep the source water as warm as possible.
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The graph below gives an indication of the possible harm caused by a refrigerant leak compared to the saving of CO2 released during a 10 year period of a heating system. Like the domestic fridge, refrigerant leaks are very rare.
Graph taken from expected consumption for a year 2002 regs. house.
10,500kWh space heating, 3,600kWh. hot water.
See ECOLOGY page for more details
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