I install a lot of high efficiency systems. 80% 16 SEER and above and 20% 15 SEER. for example Bryant Evolution / Carrier Infinity systems: There is a group of 15 of the best assemblers in the Bryant/Carrier plant that put these heatpumps/AC together. All other systems are built on a assembly line. The parts used on the systems are top notch, They are built better and they are more quiet. These systems are data controlled systems so they communicate with each component to maximize the comfort level. The compressors are 2 speed scroll compressors. ~ 3 Ton - 1 stage speed(low) runs about 5amps and high speed around 10amps. The system will run about 80% on low speed and will take out humidity with more precision. Low speed cost around 15cts an hour to run. After analyzing around 50 installs the average utility cost (heat pump) was $47 a month to run the air conditioning system in my area. The thing is, if you are going to purchase a air conditioning system. Hopefully the contractors you choose will offer and explain to you these systems. If they don't then they are not very good companies. The should offer the best! Then see if they can fit it in your budget. As a customer you want the best you can afford and should look into the top systems.

At least as far as Lowe's you are WAY off base. My company has the # 1 and 2 stores in Arizona sales and we are far from being a third rate company. We carry a 99% customer satisfaction rating and 100% referral rating with Trane. This is a no BS number as the consumer is surveyed by a third party when the system is registered with Trane. We registered over 400 with Trane last year. As far as duct leakage is concerned, we do a duct blaster and duct seal on every retro we do. We are a BPI accredited company with nine certified BA's and two manufactured Housing certified on staff. We are also an ACCA Energy Star 3.0 accredited company for new construction. We were the eighth in the country to get this accreditation. When it comes to our load calcs. Two from my company including myself just returned from from Arlington, Virginia where we spent a week with Hank Rutkowski ( the author of Manual J,D,S,T,RS,P,ZR and many more)to become certified ACCA instructors of his Manuals. We do all the estimating and loads on EVERY job we sell. All of our people have to pass background checks and NO subcontractors are allowed on any of there jobs unless they have also gone through the same checks. We are a Gold Circle NATE company ( I carry nine certs including Senior tech/Analyst ), and NCI air balance and combustion/CO certified . When you deal with Lowes, Trane and my company you have the backing of all three. Does it cost more? Not always!

wayne first off you are undersized on return. If I understand correctly, I personally think you would be better off adding a return rather enlarging and having just one return especially for size of your home. here are the numbers on system quoted. 3221082 Active Systems XL20I WEATHERTRON TRANE 4TWZ0036A1 4TEE3C04A1 36600 13.00 18.60 35200 9.00 19400 there should be no humidity issues with this system assuming you are sized correctly. I am not a fan of these two stg systems mainly because of price. However, it does seem you are getting a good price albeit still expensive on Trane's top of line XL20i with communicating air handler and stat. Here is a suggestion for a substitute system, the sgl stg XL15i. 1384031 Active Systems XL15I WEATHERTRON TRANE 4TWX5036A1 4TEE3F40B1 37400 12.70 15.00 36200 9.00 23400 You would want HW VP IAQ stat with this system. I do not like Trane's CleanEffects. Go for the HW 200 air filter or Trane's Perfect Fit 5" pleated filter media cabinet. I prefer metal trunk lines with flex supply runs. R8 insulation. what size heat strip-7.5 KW? I would verify sizing and request a load calc in writing. I don't want to be borderline in Hot Florida. how would you describe your home's insulation qualities, windows, etc? IMO Good Luck!

vanillaking I reread your original post and saw that I did not notice the ductwork modifications. It's difficult to say about pricing. Ductwork material is relatively inexpensive and more labor intensive. I can't see the scope of work from here. Many dealers though like to use ductwork changes as a good profit center. I am not saying yours is doing that. So I will give your dealer the benefit of the doubt. as far as the other quotes, one would normally expect Rheem to be under the Carrier quote and the Trane quote is simply off the wall. I am not a big fan of two stg condensers and in your case on a small two ton, the benefits if any would be marginal. Two stg can help where humidity is a factor but it is my understanding that humidity is not a big factor where you live. So on the Carrier quote, you could drop the Infinity air handler to the Performance var speed model and pair with a Carrier matching thermidistat over the Infinity controller. This can save you some substantial bucks with little difference in overall performance to the system. Yes you would lose some bells and whistles but you don't have them now so you would not even notice. Also, you could go to a sgl stg Carrier high eff heat pump system. again should be some savings. and I do recommend the 9KW pre-wired heat strip that operates in 3KW increments. This will help you in operating costs during those cold snaps. not more to add. let me know if you have questions. I can be very specific on model numbers on the outside condenser and air handler if you like. I suggest you continue working with this Carrier dealer. As mentioned in earlier post, if you have any specific comfort issues as far as HVAC, now is the time to address with your dealer. IMO Good Luck!