I currently have a lennox electric forced air furnace and it is 22 years old. My town is just getting natural gas and the gas company is giving a $3000.00 incentive to switch and they bring the gas to the house for free.

The furnace they have quoted me for is a Carrier comfort 58MCB 92%. I have the option to uprgrade to a Carrier Performance 58MTB 93% for $1000.00 more or to a Carrier Infinty 58MVB 96% for $900.00 more than the MTB.

I understand that the MCB has a single speed blower motor the MTB has a 2 stage blower motor and the MVB has a variable speed blower motor. Is it worth the extra money to upgrade from the MCB or will the MCB do the same job?