In General Issues For Attorneys In HVAC Cases, HVAC expert witness Russell M. Keeler writes on guidelines that have emerged in his industry:
Over the past 50 years, heating and cooling design has progressed from a craftsman/apprentice trade to a pursuit solidly grounded in scientific principles. The authoritative body for this fund of knowledge is the American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc. (ASHRAE).
ASHRAE funds extensive research into thermodynamics, heat transfer, the mechanics of building heat gain and loss and refrigeration. As processes become understood, the findings are published in the ASHRAE Handbook, a four volume compendium that is updated with new findings, one volume per year. ASHRAE also publishes standards for safety and testing of equipment. ASHRAE is the defining authority for heating, cooling and refrigeration.