What size is your existing furnace?...in BTUs input...I would say both quotes are oversizing furnace...both dealers are quoting 2 ton AC condenser...what size do you have now?..

IMO

Thank you for responding. The label on the old Borg-Warner says 80k BTU/hr input, minimum 48k BTU input. As you say, both estimates quote 2 ton A/C, I misread one.

All labels on condenser are gone, can find no size indication anywhere.

I suggest a 60 KBTU (no higher) furnace 80% eff with high eff blower motor paired with a 2 ton AC condenser, full cooling BTUs and best matching evap coil with AHRI matching numbers to support the system. Whole house air filter media cabinet as well.

IMO

Stick with the ones that were wiling to do the homework.

Ask them what the indoor and outdoor design temps were

If they were the same they should come very close to each other.

load calculations are tricky the BTU Requirements must match the outputs of the equipment or the equipment output would be alitle higher. HVAC-consult.com

Thanks to both responders to my question. Leaning toward the more expensive of the two Bryant furnaces--seems to meet my needs best, output 54k Btu high/35k low. System checks out as AHRI certified. Business owner ref's check out excellent, and he is giving more personalized responses to my questions than the salesman from the bigger company with Amana bid.

There have been some posters here who say to avoid Bryant Legacy, but for my short time horizon (and a good labor warranty from contractor), why buy more "quality" than I need?

Are you considering the 315AAV036070 furnace? That is from the Bryant evolution line up. That is a much nicer than the Legacy furnace. You will at a minimum a 2-stage thermostat to control it.

Mike is corrrect, same as 80% eff 2 stage var speed Carrier Infinity 80 furnace...will require a 2 stage stat...

IMO

Please tell me what you mean by "nicer"? The less expensive Legacy listed on my contractor's bid would be better than my old furnace, about which I have no complaints but it could fail any time at 34 years of age, the A/C is nearly dead so replacement is needed. The Evolution would give me higher and lower gas consumption depending on conditions, but is it built better/less likely fail?

The Evolution furnace has nicer features in that it has two stages and a variable speed blower. What that means the furnace will start up in the low stage and go to the high stage if it necessary to reach the temperature set on the thermostat. The Legacy has only one fixed speed that is set at the time of installation. The two stages provided quieter operation and it will be less prone to short cycling on mild days.

The Evolution may have a better build quality but that is subject to debate. The variable speed blower is expensive if it needs to be replaced. You would get a 10 year parts warranty from Bryant provided the equipment is registered within 90 days of installation, otherwise it defaults to 5 years. Most contractors will offer a 1 year labor warranty.

mike_home that is true if that blower motor goes out you are looking at a little over 1,000.00.

Thanks to you all who offered answers/comments. All responses are valued and help me understand what I would be getting for the extra cost of a 2-stage furnace.

My Bryant contractor offers 3 years labor warranty. Amana warrants 10 years labor, but I would spend more for this and don't expect to be here over 5 years, if that.

Wiring and installing a 2-stage tstat will cost an extra $200+, as my existing tstat setup has single stage wiring.

Final (I hope) question: how essential is surge protection for the control board? One contractor insists on, the other says not essential.

How much does the contractor want for surge protection?

$276

That's a little pricey. Supco makes a surge protector that sells for about $50. Here is the link on Amazon.

If the contractor insists on installing it then he should include it as part of his installation costs. That's what my contractor did.

One other thing to consider is that newer furnaces tend to run at higher CFMs for efficiency reasons. This causes them to be noisier than older furnaces, especially if your ductwork wasn't designed for that airflow. An oversized furnace will make this situation even worse. I definitely wouldn't go larger than 60,000 BTU input. Do have this discussion with your installer.

The OP is considering the Bryant 315AVV036070 which has a jigh stage input of 66,000 BTUs. It is the smallest size for that model. It probably will only operate in the high stage when the thermostat is coming out of a temperature setback.

Thank you all so much for your input, responders! Your thoughts have been invaluable in confirming my ideas, and giving me more issues to think about.

I have accepted the bid for the Bryant Evolution with 2-stage Honeywell tstat, based on references and responsiveness of the business owner, who will be supervising the job; the ability to have a range of fan and burner operation based on temp demands with the Evolution; and contractor's extended labor warranty. Going one-stage for furnace would be cheaper, but at age 79 I think I deserve some attention to comfort and can afford it. I do use 10 degree setbacks at night and during some day periods, so I will appreciate flexibility that the 2-stage will provide.

While some big local businesses with good reputations bid similar (or even cheaper) prices, I like dealing directly with a small business owner, especially one who has done very good work over the years for local homeowners, long-established family business with son poised to take over when his dad (with whom I negotiated) retires. As many of you have observed, the system is only as good as its installer.

Very grateful I discovered this resource for your expertise...thanks a ton (or 2 tons)!

You don't mention the model number of the HW thermostat....You want a true 2 stage thermostat that controls the furnace staging not a model that just times out to the higher stage...in your case, I think you should insist on a 2 stage Bryant thermostat.

IMO

Most thermostats on the market are made by two or three manufacturers then provide labeled for the equipment manufacturer. So you will end up with a Honeywell, Robertshaw, or W/R product with the equipment manufacturers name on it.

What you are saying is true, but communicating furnaces typical will use a proprietary protocol to communicate to the thermostat. In those case you need to buy the manufacturer's thermostat in order to get the best communication between the devices.

Based on what I have read the Bryant 315AAV furnace is not a communicating furnaces so any 2-stage thermostat should work. However if the OP purchased the Bryant Thermidistat it would be covered by the 10 year parts warranty.

Contractor wants to use Honeywell T6 Pro TH6210U2001. In reading about it on Honeywell website I do not find much detail.

Thank you mike_home for finding this info. In reading it, I see instructions for 2 heat/1cool heat pump, but not 2 heat/1 cool furnace and A/C that I am getting. There is reference in the manual to a TH622OU version that controls 2-stage heat. Looks like I will be talking further with contractor to be clear about what he is proposing. I do not have tech background to interpret how the TH621OU would fit my system.