If you don't receive the answer you seek on Houzz, try https://www.diychatroom.com/  One of my favorite "go to" sites for home mechanics and construction. Based on several replies over the years, these folks have years of experience and are very helpful. Be sure to note your location (or the nearest city), since prices may vary based on the area you live in. Best Wishes. M

What thermostat are you getting with the Carrier quote? If it is not an Infinity your won't be able to take advantage of the features of the furnace.

I think 2.5 tons for 1300 sq feet is over sized, but it may not be if it for the second floor of a house in at hot climate with marginal insulation.

First concentrate on which equipment is appropriate for your house and climate. Then compare prices on similar equipment.

I'm getting Nest Thermostat. Do you recommend to use Carrier/Lennox thermostat?

Total house is 3000 sqft. Unit is being replaced for ground floor which is of 1300 sqft.

Currently I have 3.5ton 2 units.

Replacing 3.5ton unit for the ground floor.

Location: San Marcos

Texas or California?...don't like idea of 80% eff furnace unless there is a legitimate reason....not a fan either of these lifestyle thermostats...you want the Infinity controller if purchasing an Infinity furnace...otherwise you shortchange the features of the Infinity furnace...

IMO

San Marcos Texas, Thank You. Can you advise which Thermostat and furnance to use?

I can ask Sales rep to change.

Is there any building obstacle or other reason for dealers not quoting high eff 95+ condensing furnaces? Condensing furnaces do require outside air and venting usually through an ext wall.

what is your cost for nat gas in Texas?

IMO

I see in my bill I see - 0.551 Cost of Gas/Ccf.

Your original AC of 3.5 tons for 1300 sq. feet was very over sized. The 2.5 tons is probably OK for climate. I am glad to see the contractor you are working is agreeable to reducing the size. We see many homes in Texas with over sized condensers.

You have mild winters (30 degree winter design temperature) and a low gas cost. Normally I would also recommend a 95+ efficiency furnace but in your situation the pay back for the extra cost would be a long time. I am not sure it is worth it unless you plan to live in this house a long time. You can get a quote on one of the Carrier Performance 2-stage 95%+ efficiency furnaces and an equivalent Lennox model.

If you are buying a Carrier Infinity furnace then spend the money on a Infinity thermostat. This will give you better humidity control in the summer, and keep the furnace in the low stage for most of your winter days.

The Lennox is a variable speed furnace. I am not sure if using the Lennox thermostat will give better humidity control. Perhaps one of the Lennox experts can give an opinion.

as expected, cheap nat gas for Texas...probably stay with 80% eff furnace but pair with Infinity controller.

the Lennox dealer quoted a 90 KBTU furnace, what the heck is he thinking? The Carrier will probably run on low stage most of the time for your heating season.

IMO

I'm leaning towards Carrier due to 2 year warranty and also I've a general feeling that carrier has more dealers and relatively cost effective in terms of fixing problems compared to Lennox.

I will check with the dealer if he can use 95% efficiency furnace + carrier condenser - 24APB630A.

Also I will ask dealer to change from Nest to Carrier.

Is there a specific gas furnace model like 59TP6/ 59SP5 that is > 95% efficient that you would recommend?

Also I noticed that furnace and condenser model should be compatible.

The Performance 59TP6 has the variable speed blower. The 59SP5 and the 59SP2 have multi-speed blower. In terms of heating these are all fine. The 59TP6 is the most expensive of these three, but the variable speed blower should give you better humidity control in the summer. This assumes the thermostat has a cool to dehumidify feature which will tell the blower to run at a slower speed. The Carrier dealer should be explain this to you and price out different options.

I agree with Mike...Carrier Mdl 59TP6 high eff 2 stage var speed furnace 60 K size. I expect it would operate on low stage most of the time. Thermostat

CÔR® WI-FI®THERMOSTAT
TP-WEM01-A

IMO

What is the difference between variable speed vs multi speed?

I asked the dealer to provide quote with 59TP6 and TP-WEM01-A instead of 58CVA which is a infinity series ones. Also replace Nest thermostat.

Do you recommend to go with 59TP6 instead of 58CVA? Even though 58CVA is infinity series.

The definitions may be a little different between manufacturer's models. A multi speed 2-stage furnace usually means the furnace can run at two speeds settings for heating, and and additional two speed settings for cooling. The speed selection is set up at the time of installation on the furnace control board.

Variable speed usually means the furnace will adjust the speed to based on the desired air flow. In the case of the Infinity the blower will run as fast as necessary to push 1000 CFM of air with you 2.5 ton condenser. In dehumidify mode it may slow down to 900 CFM in order to have a longer cooling cycle. As the filter gets dirty it has to produce more air in order to maintain the air flow. Think of it as having cruise control on a car as it goes up and down hills.

The main reason to get the 59TP6 is to save on heating costs which for you are low. I think the 58CVA will do a better job on humidity control when connected to the Infinity controller, but I am not sure. If that is true, then I think your case you are bettered served by the 58CVA.

Then in that case I'm good with the following, as I'm based out of San Marcos, Texas

24APB630A (Performance series)

58CVA(Infinity series 85%+ efficiency)

CNPHP3017

TP-WEM01-A - $6800

I would suggest you substitute the thermostat with the Infinity SYSTXCCITC01-B controller.

Is this Thermostat worth based on my condenser and furnance? Can you advise the benefits compared to TP-WEM01-A

Looks like SYSTXCCITC01-B costs $350 to $400 more than TP-WEM01-A

Yep, price on Infinity controller is frisky....depending on your budget and costs from dealer, I think you would be fine with the 59TP6 with the thermostat I mentioned. You need to verify with dealer that the TP-WEM01-A thermostat offers two stage heating control as well as dehumidify on demand. It should be mentioned that the AC condenser selected is not a communicating type condenser. Not trying to get down in the weeds here. Just pointing out to you and Mike that this is a downside to the 80% eff Infinity furnace paired with Infinity controller, i.e. System is not fully communicating.

IMO

The Infinity Controller has the ability to slow down the blower when dehumidifying. The controller will display "dehumidifying" when it is in this mode.

Did you get a quote with the 59TP6 furnace? The humidity control on both furnaces are likely to be close. I don't think you can go wrong with either one. The fact you have a decreased your condenser is a big step towards achieving lower humidity.

I spoke to the dealer, for San Marcos, TX weather he has mentioned that 59TP6 might be overkill. For Thermostat I'm going with Infiniti Wifi.

Model: Performance

Condenser: 24APB630A

EVAP.COIL : CNPHP3017

FURNANCE/AHU: 58CVA070

Thermostat: Infiniti WiFi

Price: $6,800 (after rebates)

Either are nice systems...I just happen to prefer the higher eff furnace over the 80...

IMO