Hi all- I am getting bids to replace my furnace and A/C, and have received multiple. The proposed vendors are Lennox, Amana, Rheem and American Standard.

Two of the companies have proposed using a 3.5 ton A/C (outside unit) with a 4 ton coil with the furnace. Both have indicated that this will provide greater efficiency.

It is interesting to note that in Colorado that Xcel Energy provides tiered rebates for replacing the A/C with a newer and/or more efficient system - but they specifically exclude any rebates for mismatches as described above.

Can anyone provide comments on the benefits or deficiencies of such a combination?

Many thanks for any feedback.