An engineering study found three main areas of concern:

• Average loss per home = 360 cfm
• Average loss (as % of sq. footage) = 19.5%

2.Refrigerant Charge

• 62 % were overcharged
• 23 % were undercharged

3. Sizing of the Unit

• 88 % were oversized
• 2 % were undersized

North Carolina Alternative Energy Corp.

This non-profit organization examined air conditioning manufacturers' efficiencies versus the actual efficiencies that resulted after installation:

• 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 criterion. 20% were barely inside the range specified by manufacturers.

1. A deficiency of 20% in air flow reduces the SEER rating by 17%.
2. A 15% return air leak from a 120� attic could reduce a 12 SEER to 6!

Texas A&M University

Found a 23% refrigerant undercharge could result in a 52% efficiency loss!

Pacific Gas & Electric

1. Found the average heating energy savings for:
2. Repair of disconnected ducts was 15%
3. Repair of diffuser leakage 7.5%
4. Correcting low air flow 5.6%
5. Repairing leaks and correcting refrigerant charge 18.4%

Honeywell

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

Louisiana 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 serviced regularly.

HVAC Manufacturer's

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