I am soliciting quotes to get a complete replacement of our HVAC.

The home is a 2100 sq. ft ranch on a slab, with an attached 2-car garage.

- about 15 miles south of Dayton, Ohio
- electric only, no gas
- ten windows (4 face west with little/no shade, 2 face south with heavy shade from trees/bushes, and adjacent home, 2 face east with light shade, and two face north with light shade)
- a regular front door
- back door is two doors side-by-side, but only one side opens (the other is basically a big door-shaped window), faces west, with moderate tree cover
- the ceilings seem normal
- there is a fireplace in our rec room
- the rec room is at the north end of the home, and has its own return , with two incoming registers on the adjacent and opposite walls
- air handler smack in the middle of the home, condenser in back

Priorities (in order)
- energy efficient
- keeps us comfortable
- quiet

We are committed to getting:
- variable speed
- heat pump
- puron refrigerant

We plan to stay in this home 10-30 years.

I have had 5 people come out.

1) Thorough and seemed knowledgable, recommended Trane variable speed blower (3.5 ton) and XL14i condenser (3 ton). Company is large and experienced and "we use our own contractors...no subcontractors". They have 5 BBB complaints, which have all been resolved.
2) Seemed experienced, but also uncertain about size/strength/support of company. Discussed Bryant system. Still has not provided written quote. No BBB file.
3) Thorough and seemed knowledgable, but laid on the sales pitch a little hard; shocked at the 3.5 ton recommendation from #1 (he recommended 3 ton); recommended Lennox variable speed fan with XP15 or XP16 heat pump. Company is small to medium-sized and experienced, but has 7 complaints in last 3 yrs, only 4 resolved, other 3 GFE.
4) Thorough and seemed knowledgeable. Waiting for him to run calcs (he only stopped by last night). He is initially recommending Lennox Signature CBX31MV/CBX32MV and XP19 heat pump. Age/size of company uncertain, as their BBB file is one month old (they apparently acquired/transferred assets recently and the old company has no listing in the BBB).
5) Coming out Saturday. Small company, part of a larger company; they have 4 complaints, with 3 resolved and 1 GFE.

It feels like these recommendations are all over the map, and of the 4 that have BBB files, I don't feel any of them sound bad enough to eliminate them.

#2 is dropping from contention due to lack of quote (over a wekk now), lack of BBB file, and the impression that he was a one-man operation (and to be brutally honest, I think our HVAC will live longer than him).

I have not tracked down a pro-Carrier contractor just yet.

I need help narrowing some specific choices down:

Tonnage
- What tonnage should I be getting?
Does 3.5-tons sound crazy (I can't find that option for Trane anyway)?

SEER
- What SEER rating should I really shoot for?
- Are there significant diminishing returns aobut 15?

Humidifier - should I consider one? We are thinking no.

Air cleaning
- We are suspicious of the efficacy of UV lights, given that we use them in our labs and you really need 30-60 minutes of constant irradiation for good sterilization. Hence, we fear they are just gimmicks, unless we get more information that makes the UV lights in air cleaners work much more effectively.
- Guy#1 recommended an Aprilaire filter
- Guy#3...I don't remember actually
- Guy#4 recommended the PureAir system