Rheem offers a full line of energy efficient units.  Again tested and true, Rheem is the air conditioning unit we choose over all.  In the typical "split air conditioning system", refrigerant circulates between an indoor coil and a matching outdoor condenser with compressor. The refrigerant cools the air, dehumidifying it in the process; a blower circulates air through ducts throughout the house.

This describes how much cooling the unit delivers for each watt of electricity. Efficiency is expressed as the Seasonal Energy Efficiency Rating, or SEER. At present, a SEER of 10 denotes a low-efficiency unit; medium efficiency is 11 to 14; high efficiency is above 14. New federal regulations that took effect in 2006 set the minimum SEER for a central air conditioner at 13.

E.E.R. (Energy Efficiency Ratio) rates the cooling efficiency of HVAC units. E.E.R. equaled the rated cooling output of an HVAC unit in BTU's per hour divided by the rated input of energy in watts of electricity, at specific humidity, and temperature input/output conditions.  To calculate EER you just divide Total Capacity by the Total KW energy usage..

S.E.E.R. is a seasonal rating most typifying average residential usage in the US.

        E.E.R. is at a single rating point and more represents peak load rating. 

       High rated S.E.E.R. Air cooled HVAC unit rating falls as the temperature gets hotter and in turn cost more to operate.

        S.E.E.R. conventional air-cooled units are rated at 83 degrees. The operating efficiency is lowered by two points for each ten-degree rise in the temperature above the 83-degree test standard. A 12 SEER air-cooled unit will operate at an 8 to 9 SEER on a 105-degree day. 

• Raise the thermostat as much as you can without sacrificing your comfort. For every degree you raise the setting, you can expect to cut your cooling bills by 3% or more.
• Use shades, blinds, curtains or your vented awnings to keep the sunlight out.  Especially in the afternoon in rooms facing west.
• Plant trees and shrubs to keep the house and the air conditioners outdoor component in the shade, yet still allow air to circulate.  Deciduous trees are a good choice because they let the sunlight in during the winter but block it out in the summer.
• Regularly clean and or replace the air conditioners filter-even monthly during heavy use.
• Keep fallen leaves, grass clippings and other dirt and debris away from the air conditioners outdoor system.  Keep the coils clean.
• Run your ceiling fans to keep air moving, you'll feel cooler and can cut back your air conditioner use.
• Consider a programmable thermostat, why cool your home down if no one is there, set it to come on during your drive home