Cost Estimating: HVAC

Technical Rules of Thumb: (and Conversions): (external link) {external link)
Patent: 2013: Trane: Systems and Methods for Estimating HVAC Operation Cost: (external link)
Military Life Cycle Cost Analysis: 1991: (external link)
HVAC (Mechanical) labor hours: SMACNA
The Engineering Toolbox (external link)
Ershigs FRP Piping / Ductwork (external link)
HVAC Components (internal link)
MCAA labor hours: Mechanical Contractors Association of America (MCAA)

Cost Estimating: Cost Books and Cost Guides (internal link)

Rough Guess (Commercial Building): Lbs of Ductwork = Sq Ft of Building area [Rough Guess]
Recommended is an actual takeoff be used.