From the Publisher;

This 4-page, full-color card quickly covers essential heating, ventilation and air conditioning (HVAC) formulas and equations. Includes several quick lookup tables ...

HVAC Rules-of-Thumb Fans (Basic Fan Laws, More Fan Equations) Ductwork and Air Flow

Equivalent Duct Sizes

Air Flow in a Duct

Required Main Duct Sizes (table)

Air Flow for HVAC (Sensible Heat) Ductwork Pressures

Pressure Drop in HVAC Air Ducts

Reynolds Number

Heat Loss or Gain (Buildings) Steam Heating or Cooling

Common HVAC Formulas for Air and Water Energy Efficiency Calculations

Energy Efficiency Ratio (EER) Coefficient of Performance (COP) Seasonal Energy Efficiency Ratio (SEER) Heating Seasonal Performance Factor (HSPF) Annual Fuel Utilization Efficiency (AFUE) Useful Conversions

R-Value AC Condensate Flow

Combustion Air-Opening Sizes (table)

4 pages, laminated. Builder's Book, Inc. (January 2007)