If you operate a large heater for process heating, it may be possible to cut its fuel costs significantly. If the heater has a net thermal efficiency of 80 percent or less, it is wasting a lot of fuel. That is well below the efficiencies of heaters currently available.
By changing to a heater with high thermal efficiency, it may be possible to achieve substantial savings over the course of a year. Obviously, the amount of savings depends on several variables such as the cost of fuel, the number of hours the heater operates, its heat load, etc.