All JC BORDELET wood-burning stoves and fireplaces with closed hearths have excellent performance ratings. However, due to the nature of the fuel, a fireplace or stove cannot be used as the primary heating system. If there is no fuel in the house, the fireplace cannot be reloaded. The availability of fuel determines whether you use the main heating system or the backup system. It is therefore very important to have good quality insulation in the house. The performance figures for our fireplaces are for guidance only and post-test comparisons refer to optimal conditions (installation, insulation and fuel). The values recorded under standard conditions may vary if the conditions of installation and use are not equivalent to our test conditions.