In 2009, Conservation Services Group conducted a pilot installing brushless fan motors (BFMs) in residential heating and cooling applications for residential customers. The objective was to determine the "real world" effectiveness and energy saving potential of replacing existing permanent split capacitor (PSC) furnace and air handler motors with high efficency BFMs. The initial 50-unit pilot initiated in May 2009 quickly demonstrated the savings achievable, and a second phase of 150 BFMs was approved in midsummer. Selected contractors were trained by factory representatives and CSG staff in proper installation, and CSG staff provided on-site installation assistance with the contractors. Upon examination of the installation data from the first phase of the pilot, CSG decided to conduct a "Pilot Within a Pilot" to determine: 1) optimum conditions to maximize savings potential 2) duct diagnostic tests (high TESP) to identify and troubleshoot poor candidates 3) duct modifications that could potentially double the savings, and 4) perform these modifications to demonstrate the optimal BFM program design.