Normally I don't do it but since this was for close friends 15' to the south, I did!
Noisy 60% furnace, 8 SEER leaking A/C, time to do something. But what? With our gas prices, 90% furnace. But 12 SEER A/C? Nope, payback of $20 per year isn't worth it. For same premium as 12 SEER A/C over 10 SEER A/C, I can install a 10 SEER heat pump and save them $200 a year. So that's what we did!
The old furnace, wall behind it is master bedroom.
The old A/C, 2 ton and a hair undersized. All the houses in our neighborhood are 2 ton regardless if tiny like mine or 2 story like this one! Note the coil damage from Tom's dog's chain years ago...
The new 93% AFUE furnace. Donna says much quieter inside. Dedicated low speed constant fan tap helps too. Vented out the side wall due to living area above. In the metal above the furnace is a slot for a 5" media. We're using the Honeywell F200 media, MERV 11.
The 10 SEER heat pump. Went to 2.5 ton which is really about 2 1/3 ton these days. Put a sound blanket on the scroll, can't hear it. Just hear the fan. Note the UFO on the wall, used A-S/Trane's BAYVENT200 kit. System is controlled by Vision Pro 8000 stat which is our dual fuel kit. Outdoor thermistor is hiding behind the unit.