2 System Replacements - Advice/Guidance needed.

We've had problems with both A/C units every year and now the main unit is dead. It is a freon system and we don't want to through money down the drain to pay for 9 lbs of freon just to have it leak out from a system that needs to be replaced anyway. Our furnaces are basic builder grade, installed in 2003, and have had problems of their own....but were fixed and seem to work fine at the moment. It was explained to us that there is no "real need" to replace the furnaces but the Carrier Systems that were being recommended are more efficient together and with the purchase of the furnace and the A/C units together would provide a more comfortable home and that Carrier Infinity series had some great rebates being offered that we should consider it an option.

Of all the research we've done (this started last year) - we've selected and are most confident in the Carrier Brand to replace our low level builder grade systems we have now. We have a lower level unit to cover the main floor (2,000 sq.ft) and finished below grade basement (2,000 sq. ft). The upper unit is in the attic to cover the upper level (2,000 sq. ft). We live in the Northern Virginia/DC area. The entire back of our house gets full southern exposure from the sun and the amount of heat that penetrates through the windows is amazing. (We have 18 windows in the back of the house and 6 on the sides that are hit by the sun from 10am until 8pm. Even with the A/C working and set to 72 degrees for the upstairs, our master bedroom on the back of the house can register in the mid 80 degree range. Our summers are hot and humid and I am always closing the blinds and keeping the lights off to keep things cool.

We are currently being offered the following:

Lower Level to cover the main floor and basement: Carrier Infinity Series

Carrier A/C Model 24ANB748 with Coil which is 4 Ton, 16 Seer, 2 stage

Carrier Furnace Model 58CVA 110-20, 2 stage, AFUE 80%.

Carrier Thermostat Control: Model Systxclu1001 (I may not have that 100% accurate - hard to read on the estimate)

Upper Level: Carrier Infinity Series

Carrier A/C Model 24ANB736 with Coil which is 3 Ton, 17 Seer, 2 stage

Carrier Furnace Model 58CVA 090-16, 2 stage, AFUE 80%.

Carrier Thermostat Control: Model systxclu1001

1. Does the above combination make sense?

2. Would the Infinity Furnace 96 (AFUE) be better? What I read from Carrier says it's more efficient and it obviously costs a little more money. What would be the downside to this over the Infinity Furnace 80 (AFUE) and how much additional would be reasonable to pay for this upgrade - assuming there is a benefit.

3. We were also given the option for the lower level unit to be the Infinity Hybrid A/C Heat Pump combo. Since our average gas bill per month is around $150, they put it on the estimate but said if it was "their" house, they would spend the extra $1,100 on the system to save an estimate of $10/mo in bills. Is this assessment/statement accurate or somewhat close to accurate?

4. Does the Infinity thermostat/control system come with the remote access and silencer system II technology - I can't tell from what I read. Some articles make is sound standard and other articles make is sound like these are upgrade items for a cost. If so, what would those upgrades actually cost? I am more interested in the silent technology...probably because our current system is very loud in the house and it bothers me.

5. I read online that the Carrier labor and parts warranty is transferable - If we sell our house it can be transferred to the new owner......is this true?

All of the above price before discounts was $21,000...but after the Carrier Rebates and the company "10% discount" for the "large combo purchase" the final price was $15,000. This price includes the Carrier 10 year parts and labor warranty as well as the following:

New 60 outdoor connect box, New foundations for outdoor units, Insulate refrigerant suction lines, Install refrigerant drier/s, Recover/Evacuate/Flush/Charge to specs, Connect furnaces to present duct system, New condensate drain system (supposedly the current drain system was never connected to the unit by the builder), Install condensate drain pan with float switch (because there is a plastic one there now that they don't recommend due to the fact that it holds the furnace above the floor of the pan which risks a potential imbalance of the unit), Installation of new thermostats, responsible for permit, removal of existing equipment, complete system start up, 10 year compressor warranty and 20 year heat exchange warranty.....

I have no idea if the estimate is good muchless accurate for our home. The owner of the HVAC company has the Carrier Infinity series in his home and he just installed the recommended upstairs system in a neighbors house with high recommendations. The fact that we are without A/C on the main and lower level at the moment with a current heat index is 105 degrees with southern exposure from the sun and a master bedroom that has the A/C working upstairs only cooling to 86 degrees makes us feel like our back is against the wall.

If we selected to only proceed with the Lower Level recommendation - then the estimated price would be $8,600.....but it doesn't say if that is before or after the rebates/discount on the estimate.....let's assume it is after the discount.

As expensive as the above is....we have more questions and wonder if it would be beneficial to add 2 additional items for efficiency and more importantly comfort...

1. Carrier Infinity Air Purifier - we have a basement that is below grade with only a few small windows and an areaway walk-up. The basement is starting to smell musty and feel damp. Additionally, the amount of dust in the air throughout the entire house is more than what I would consider normal. Would the Carrier Infinity Air purifier help either of these issues? or would the installation of the recommended systems be all that would really be needed. We don't have major allergies or have any health issues, but we have 2 kids and don't want any potential mold spores in a damp basement to start infecting the air and have effects later down the road. If the air purifier can help with the above, what is a reasonable cost to add this to our request?

2. Whole House Steam Humidifier - this is something that the owner of the HVAC company highly recommended when he saw 8 boxes for portable humidifiers in our basement Furnace area. We've gone through 2 units for each of the 4 bedrooms on the upper level of the house in the past 4 years. He said that the AprilAire 800 Steam humidifier will help keep the humidity level in the whole house at a constant level (making it a more comfortable home) - The humidifier supposedly can humidify and De-humidify....depending on what the house needs. I really like this add on - but the cost quoted was $2000. That seems a bit on the very high side....Could it be the fact that there is an additional cost for it to be connected to our circuit breaker? I went online and I can buy the humidifier myself for $650-$800. I know how to fish wires through walls and ceilings....but I'd hire an electrician to connect to the circuit breaker.....or is the $2000 realistic?

Any opinions, thoughts, questions, issues would be greatly appreciated. Thanks.