Rule of Thumb Uses in HVAC Design Rule of Thumb Uses in HVAC Design irfanaboo (Mechanical) (OP) 12 Aug 14 03:25 Where we can find the rules of thumbs for HVAC design ? Is that always comply with ASHRAE ? RE: Rule of Thumb Uses in HVAC Design cdxx139 (Mechanical) 14 Aug 14 14:31 Rules of thumbs come from experience. You can also try HVAC Equations, Data, and Rules of Thumb, 2nd Ed, by Arthur Bell knowledge is power RE: Rule of Thumb Uses in HVAC Design Ziggypump (Mechanical) 29 Aug 14 14:23 Rule of thumb to meet ASHRAE: Always reference the ASHRAE material. The Rules of Thumb book by Bell is great.