Variable speed air handler?
 

We're replacing our AC and are trying to decide between a variable speed or single speed air handler.

Variable speed supposedly adds comfort by removing humidity, may use less energy, and may be quieter. I haven't been able to quantify any of these, though.

I also know a variable speed motor is more likely to break and is more costly to repair, but again no quantitative information.

Both units are 15 seer and have an $410 difference.

Any advice?

We got a top of the line Infinity Carrier unit a few years ago. They said it was more efficient and more comfortable. I had my doubts, but honestly, you could really tell the difference in comfort as the temps seemed to stay very constant. I'd buy another one in a heartbeat. Not sure it has a variable speed handler, but it is a two stage unit. Highly recommended. Hope that helps.

Really need more information. Is the condensing unit a 2 stage variable speed compressor or does it have a single stage compressor. Is it a Trane unit or another brand? Trane uses their own compressor design while every other manufacturer uses the Copeland Scroll compressor.
Do you run your fan constantly or do you let it cycle as the thermostat demands?
Do you have a humidistat? Do you have an add on dehumidifier on the system?

Couple of fairly informative articles from the leading news magazine for the HVACR business. There is a little quantitative information in the one but there are a lot of variables that can effect the efficiency of a system.

http://www.achrnews.com/articles/118...d-to-customers

http://www.achrnews.com/articles/112...r-technologies

We're looking at a Bryant preferred series, single stage, 4 ton unit. We let our current unit cycle, no humidistat, no added dehumidifier.

This thread gets me thinking about Bugeater.

Haven't seen him in a while. Anyone know if he's ok?

Chances are he ate a bad bug. He's prolly dead .

Had one in our last house and noticed improved comfort when heating.

Alright, Bryant is Carrier in case you didn't know. Good Equipment.
If your duct is insulated and properly sealed along with your home being normally well insulated it will save you in the neighborhood of 20-30% as mentioned in that one article.
You should notice more air comfort through dehumidification but it will not be truly "adjustable" without a humidistat. When I installed this brand of systems the Infinity thermostat was the bomb. It would do amazing things that I am sure you don't really want to hear about.
You should notice the system being overall quieter because the fan will ramp up and down as the system cycles.
The motors are half again to twice the price but they should last 5-10 years without an issue. They would last at least that long back when I was putting these things in and they have improved the technology since then I am sure. When our rep came out to visit as well as the classes we took on these units Carriers people always told us that the motor should last 2-5 years past the warranty.

It should save you the difference in price the first year, maybe year and a half. The motor will last as long as you don't leave the blower on instead of the auto selection and it will use a few more watts, but the real issue is longevity of the motor.

Ecm in KC gets you a rebate from mge also.