I’ve been trying to figure out how much my gas / heating / showers were costing me, but I’ve hit a fairly big discrepancy that I can’t explain.
I have a brand new 28kW/h rated boiler, with 98% efficiency rating, and according to the service manual it will consume 28.57kW/h max worth of gas, or 3.02 m^3 per hour.
I have found through measurement of having a 7 minute hot shower that the boiler was running full whack, consuming exactly at the rate claimed by the guide, 3.02 m^3, but this equates according to my bill to be 34 kW/h.
Where is the extra energy going / being wasted?
|Gas Max Flow Rate||3.02||m^3/hr|
|Max Heat In:||28.57||kW/h|
|Max Heat Out:||28||kW/h|
|Gas Qualities / Constants|
|kW/h / MJ||3.6|
kW/h at Max Flow = Max m^3/h (3.02) * Calorific Value (39.7) * Conversion Factor (1.02264) / kWh per MJ (3.6)
kW/h at Max Flow = 34.0578889333333