• 90%of the units tested exhibited some sort of energy wasting problem
• 50% had an improper refrigerant charge
• 40% failed to meet minimum air flow criteria
• 20% were barely inside the range specified by manufacturers
• A deficiency of 20% in air flow reduces the SEER rating by 17%
• A 15% return air leak from a 120° attic could reduce to 12 SEER to 6!

Texas A&M Universityfound a 23% refrigerant undercharge could result in a 52% efficiency loss

Pacific Gas & Electric found the average heating energy savings for (1) repair of disconnected ducts was 15%, (2) repair of leakage 7.5%, (3) correcting low air flow 5.6%, and (4) repairing leaks and correcting refrigerant charge 18.4%

Lakeland Electric & Water researchers found that by repairing leaking duct work, cooling energy was reduced by an average of 17.4%.

Honeywell found that heat pumps lost almost 50% of their efficiency after 20 years, even if typical "dust stop" filters were installed. In 20 years, a 12 SEER unit could degrade to a 6 SEER. This would double the energy cost!

Lousiana State University and Gulf States Utility found consumers could save about $30 per month just by making sure that their air conditioning system was cleaned and seviced regularly.

HVAC manufacturer's data shows a condensing unit with a SEER of 13 matched with an old air handler would decrease the SEER to 9.2, resulting in 30% less efficiency.