Useful Tools
Ten free HVAC, indoor air quality, gas measurement and analog signal calculators. Estimate cooling capacity, airflow, ventilation and comfort conditions, or convert gas measurements and analog transmitter signals—right in your browser.
HVAC BTU Calculator
Estimate room cooling capacity in BTU/h, kW and tons.
Open calculator →ACH Calculator
Calculate air changes per hour and the airflow for a target ACH.
Open calculator →CFM / m³/h Converter
Convert airflow between CFM, m³/h and L/s.
Open calculator →Ventilation Requirement Calculator
Estimate breathing-zone outdoor air using people and area design rates.
Open calculator →Dew Point Calculator
Estimate dew point from indoor temperature and relative humidity.
Open calculator →CO₂ Ventilation Calculator
Estimate outdoor air for a steady-state indoor CO₂ target.
Open calculator →Gas Measurement & Signal Tools
Convert gas concentrations, compare flammable-gas reference values, and calculate general-purpose analog transmitter signals.
Gas Concentration Converter
Convert between ppm, ppb, % vol, mg/m³ and µg/m³ using gas molecular weight, temperature and pressure.
Open calculator →%LEL, %Vol & PPM Converter
Convert flammable-gas concentrations with visible, editable gas-specific lower and upper explosive limits.
Open calculator →4–20 mA Calculator
Convert 4–20 mA, 0–20 mA or custom current signals into any configured engineering measurement.
Open calculator →0–10 V Calculator
Convert 0–10 V, 2–10 V, 0–5 V or custom voltage signals into any engineering measurement.
Open calculator →About these calculators
These tools use stated mathematical relationships and transparent assumptions. Results are educational estimates and signal interpretations—not substitutes for manufacturer documentation, professional engineering design, hazardous-area approval or regulatory compliance review.