초록 ▼

In a gas furnace designed for operation with natural gas, the use of propane as a fuel is facilitated by increasing the inducer speed by a factor which is obtained by comparing the higher inducer speed necessary to bring down the heat exchanger temperature to an acceptable level, with the original l

In a gas furnace designed for operation with natural gas, the use of propane as a fuel is facilitated by increasing the inducer speed by a factor which is obtained by comparing the higher inducer speed necessary to bring down the heat exchanger temperature to an acceptable level, with the original lower inducer speed that had caused the temperature to exceed the allowed limit. Provision is made for electronically applying the multiplying factor by simply operating a gas selector switch.

대표청구항 ▼

A method of using propane at a predetermined input rate in a burner of a furnace of the type designed for operation with natural gas at the same gas input rate and with a heat exchanger having a predetermined temperature limit and having its combustion air supply level controlled by selective regula

A method of using propane at a predetermined input rate in a burner of a furnace of the type designed for operation with natural gas at the same gas input rate and with a heat exchanger having a predetermined temperature limit and having its combustion air supply level controlled by selective regulation of the draft inducer motor speed, comprising the steps of: establishing the desired draft inducer motor speed when natural gas is used in the burner; applying to said desired speed a predetermined multiplier to obtain slightly higher speed and excess air levels for combustion; and operating said draft inducer motor at said slightly higher speed when using propane in the furnace to thereby maintain the temperature in the heat exchanger below the predetermined temperature limit.