Proctor Engineering Group - HVAC/Duct System History

Proctor Engineering Group
HVAC/Duct System History, continued

1991 Pacific Gas & Electric
Model Energy Communities Project
(Over 2000 Air Conditioners)

Duct Leakage to Outside.(Pre) (Flow Hood Method)

Duct leakage exceeded 150 CFM 50 in 98% of the systems. It averaged 381 CFM 50 and ranged from 36 to 8130 CFM 50. Sample size 2170 homes

Duct Leakage to Outside.(Post) (Flow Hood Method)

Duct leakage was below 150 CFM 50 in 64% of the systems after repairs. It averaged 154 CFM 50 and ranged from 1 to 900 CFM 50. Sample size 2170 homes

Percent Reduction in Duct Leakage to Outside.

Duct leakage was reduced by an average of 60% on the homes treated.

Low Air Flow

Air flow measured across the indoor coil was deficient by more than 50 CFM/Ton on 44% of the systems. Sample size - 175 systems.

Refrigerant Charge

Systems were found to be undercharged in 22% of the sample. Thirty-three percent of units were overcharged and 45% correctly charged. Sample size - 175 systms.