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How to calculate power consumption


A simple calculation to determine your infrared heating energy consumption, versus oil-heaters.


  Infrared heating consumption:  
1)  Calculate the room volume (width x depth x height) = m3  
2)  Calculate the infrared consumption = Room volume (m3) x 25 Watts  
3)  Cost per hour = Consumption (answer in 2) x unit cost of electricity (currently about 14p per kWh)  
4)  Divide total running time by 3 (Redwell panels draw app. 1/3 of the total time they are on).  


  To calculate oil heating consumption: 
1)  Calculate room volume as above 
2)  Calculate Radiator output watts = Room volume (m3) x 45 Watts 
3)  Calculate Boiler output watts = Radiator output watts + 10% (due to loss between boiler & radiator)  
4)  Calculate Boiler Consumption Watts = Boiler output watts (from 3 above) divided by "age deflator" (see below *) x 100.  
5)  Divide kWh figure in 4) by 10.22 and multiply that figure by the per-litre cost of your oil. **)  


*) The "age deflator" is used for the fact that boiler output efficiency degrades over time. About 3 years old burners are generally 90% efficient, so your deflator is 90. 3-5 year burners are considerd 70-80% efficient so your deflator is between 70 - 80. A boiler older than 5 years can be as little as 55% efficient so your deflator is 55.

**) 10.22 is the generally accepted figure for "kilowatts per litre" and by using the age deflator above, you can take into account the efficiency of the burner.