Fireplace units using different fuel types have very different heat outputs. Operating costs of fireplace units should be compared taking account of heat outputs, fuel costs per hour and fuel costs per kWh.
The tables below compare typical units using different fuel types in terms of the above measures. The costs are based on current prices of particular suppliers in the Johannesburg region. Costs will vary depending upon the fuel supplier and the geographic region. All costs are subject to escalation, unfortunately at different rates for the different fuel types. The tables provide a comparison at April 2011.
Fireplace units with larger heat outputs (for larger volumes to be heated)
| Fuel | Assumptions & notes | Typical heat output of fireplace unit | Approx fuel cost | Approx cost per kWh |
| Wood (in closed system fireplace) |
|
8 kW | R2,09 per hr | R0,26 |
| Bottled gas LPG |
|
|||
| Heat & Glo SL550 | 5,5 kW | R8,67 per hr | R1,58 | |
| Efficient open gas fires | 5 kW | R17,33 per hr | R3,47 | |
| Less efficient open gas fires | 5,5 kW | R20,00 per hr | R5,20 |
Open fireplaces burning wood and/or anthracite are not included above as there is little demand for these units at present. An open wood/anthracite-burning fireplace is considerably less efficient than a closed system fireplace.
Wood-burning closed system fireplaces are the most cost efficient by any measure. Heat & Glo gas units are significantly more cost efficient than open gas fireplaces.
Fireplace units with smaller heat outputs (for smaller volumes to be heated)
| Fuel | Assumptions & notes | Typical heat output of fireplace unit | Approx fuel cost | Approx cost per kWh |
| Bio-fuel |
|
2 kW | R20,23 per hr | R10,12 |
| Electricity
|
|
2 kW
(see note below) |
R1,20 per hr | R0,60 |
The electrical costs above are obviously for electrical input, not heat output. The efficiency of the appliance will determine the heat output. Nevertheless, it is clear that electric fireplaces are the most cost efficient for small areas/volumes.