#btu

HVAC sizing maths as an API, computed locally and deterministically from standard rule-of-thumb factors. The cooling endpoint estimates the air-conditioner load for a room — in BTU per hour, tons of cooling and kilowatts — from the floor area (in square feet or metres, or length × width) using a baseline of about 20 BTU/h per square foot, with adjustments for the number of occupants, a kitchen, sun exposure and ceiling height. The heating endpoint estimates the heating load from the area and a climate zone (mild through very cold) or a custom BTU per square foot. The convert endpoint converts between BTU per hour, tons of cooling, kilowatts and watts (one ton = 12,000 BTU/h ≈ 3.517 kW). Everything is computed locally and deterministically, so it is instant and private. These are rule-of-thumb estimates in the EnergyStar style — a proper Manual J load calculation accounting for insulation, windows and local climate is recommended for a real installation. Ideal for HVAC and home-improvement tools, air-conditioner and heater sizing guides, smart-home and energy apps, and contractor quoting. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is HVAC sizing; for appliance running cost use an energy-cost API.

api.oanor.com/hvac-api