HVAC load estimator
BTU/h cooling + heating from area, exposure, and IECC climate zone. This is a rule of thumb — a sanity-check the mechanical engineer’s Manual J / N output, or a back-of- napkin during early scoping. For a real design, run Manual J.
Cooling coefficient = base BTU/SF (20-32 depending on exposure) × IECC-zone multiplier (0.80 to 1.15). Heating coefficient = 20 to 55 BTU/SF, increasing with climate zone (1 to 8, warm to cold). Tons cooling = BTU/h ÷ 12,000. These coefficients are the same numbers the bot inside Forward uses for its texting-interface estimates — see hvac_load_estimate in apps/api/app/llm/calculations.py.
Want this answer over text inside your project?
Forward is a phone number your field crew + PMs text. The bot runs HVAC load, duct sizing, CFM-for-BTU, ventilation CFM-required (ASHRAE 62.1), and a dozen other mechanical calcs straight from a text message. Same number also pulls RFIs, drawings, submittals, change orders from Procore + Autodesk + OneDrive. No app, no login.