It is true that the builder's grade (low end) model of the Carrier/Bryant line up is the same as one of the Payne models. The warranty period on the low end and Payne models are shorter for the heat exchanger and parts.

Unless you are very tight on funds, or plan to move soon, I would avoid Payne and any builder's model furnace. Spend a little more money and get a better furnace.

I am also not a fan of moving a furnace from a conditioned space (laundry room), to an unconditioned space (attic). The move is expensive and the energy performance will be reduced.

Thank you for your advice! I am not moving and planning to stay longer.

Which model would you recommend? I don't need more than 80%?

What furnace do you currently have? Is it powered by natural gas? Do you have an air conditioner? Why are you moving the furnace?

I have a gas furnace, no air conditioner ( not planning to put one for right now) - I need to free the space so I can build a second bathroom. The house is 1500sqf. The furnace and the water heater are in the laundry room together with a 1/2 bath ( toilet and sink).

Ask the contractor for quotes on the Comfort and Performance series furnaces. Since this is an attic installation I suggest an 80% efficiency furnace. The duct work in the attic should have R8 insulation.

I would also recommend asking for a load calculation to verify it is the correct size. It would be good if you got a 4 inch media filter, but this may mean going into the attic to change it. A 4 inch filter should last a year.