I am looking at intsalling a central air unit in my 1800 SF home. Our old unit is going out and I am interested in spending the money to get the most energy efficient unit. I see the websites quoting SEER ratings of 23 when the companies I talk to only refer to SEER ratings of 16 to 18 max. Can you help me understand why I am not seeing the higher ratings.

http://www.maytaghvac.com/M1200acah23.asp
Couldn't find the current Lennox Signature series SEER ration, also high.

The main reason the higher SEER units are not available in most areas is because the pay back time in money far exceeds the life time years of the unit. As you go up in SEER so does the cost of the units and in most areas the extra costs of the units will take forever to recover. The utility bill will be a bit cheaper but a long pay back just does not make sense for the average person.

Now the cost of utilitys will continue to go up over time so the cost basis may someday make the extra money for a 23-24 SEER manageable.

One last thought. Most HVAC companys according to records and statistics do not have a staff qualified to install and accurately charge a 13 SEER machine let alone a 23 SEER. All it takes is about one ounce difference in a refrigerant charge on a piston/cap tube system to loose up to one SEER of efficiency.

What area are you in? Is this a heatpump or a straight ac unit?