How much energy can be saved through use of proper refractory and insulating materials?
Note that the heat loss calculated using Figure 1 or any other method should be corrected for the “available heat” for a heating system, particularly in a fired system that uses combustion of fuels such as natural gas. The available heat is the amount of heat that remains in the furnace after accounting or subtracting heat contained in flue (exhaust) gases leaving the heating system. The available heat for a fuel-fired heating system can be calculated by using graphs provided in Reference 1 (PDF 2.4 MB) or other industrial combustion books. Download Adobe Reader. The actual heat required and energy cost to compensate for the calculated wall heat losses could be considerably higher than the cost of energy calculated without correcting the heat loss calculated for the available heat.
