which AC unit for second floor of a bungalow?
Doing a gut reno of my second floor. The house is a bungalow so it gets nice and toasty up there in the summer. General footprint is roughly 60'x13' consisting of two bedrooms and two full baths. GC/HVAC determined that our current system isn't enough to support full-time, comfortable living up there -- at the moment we live strictly on the first floor, and as a 1946 house I don't think it was ever optimized for comfort upstairs. The HVAC guys have been here all week running all new ductwork and installing the furnace (Lennox SLP98). Also added R-21/R-13/R-38 wherever we could.
We need to choose an AC unit and I'm questioning what the HVAC guys have spec'd out. They're planning to install a Lennox 13ACX-024-230 and maintain that this is adequate for the space. While I believe that, we plan to be in this house for the next 20 years at least -- would it make more sense economically to move up to one of the following?
XC13-024-230 $350.00 additional
XC14-024-230 $625.00 additional (quietest according to HVAC guys)
XC16-024-230 $1,200.00 additional. 2-stage. Seems like overkill.
Utility rebates in my region are $150 for 15 SEER, 250 for 16 SEER.