An engineering study found three main areas of concern:
- Average loss per home = 360 cfm
- Average loss (as % of sq. footage) = 19.5%
- 62 % were overcharged
- 23 % were undercharged
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.
Did You Know?
- A deficiency of 20% in air flow reduces the SEER rating by 17%.
- 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
Found the average heating energy savings for:
1. Repair of disconnected ducts was 15%
2. Repair of diffuser leakage 7.5%
3. Correcting low air flow 5.6%
4. Repairing leaks and correcting refrigerant charge 18.4%
- 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.
- 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.