' My SIL asked me to do some research for her. She's interested in a forced air furnace for her 3000 sq. ft. home and doesn't know which kind to buy. Rather than ask a heating expert, who may or may not sell you his/her special brand, I thought I would ask here. Does anyone have any special preferences as to which kind they like/would like to have? What would be the reasons? Thank you.'
There are many good brands out there ; it comes down to how important is name recognition to you and how much are you willing to pay for a fancy advertising budget being put into the cost of the equipment . If you feel you need a well recognized name, like Carrier or Trane, then be prepared to pay out about 30-50% more to cover the enormous marketing program they have AND...the Carrier Dealers attitude that he can charge more cause : 'Its a 'Carrier' . Same with Trane and Lennox.
If brand recognition is not all important and you dislike paying for a manufacturers advertising scheme, then there are a number of good brands out there that will work just as fine, will last just as long, will be just as reliable. Such brands are : Goodman, Tempstar, and a few others which im sure the average consumer hasnt heard of.
Also, the installer and his how he installs the equipment is very important in your consideration too. Make sure he doesnt have the typical darkside attitude of the hvac trade, as readily found in : Alt.HVAC newsgroup.