About J1 Pro

Free, transparent design calculators for HVAC and MEP engineers.

J1 Pro is built by a practising HVAC/MEP design engineer based in Dubai, the person behind the J1 Tamil YouTube channel, which teaches HVAC design in Tamil. The calculators started as tools for day-to-day project work and for viewers of the channel, and grew into the J1 Pro Android app and this website.

What we believe

Show the working. Every calculator shows its formula, the substituted values and the design basis, so you can check it and explain it to a reviewer.
Use recognised methods. Calculations follow standard engineering references such as ASHRAE Fundamentals, with the method stated on each tool.
Stay useful first. Ads are kept to a minimum and never placed inside a calculator.

Where else to find us

J1 Pro – HVAC & MEP Tools on Google Play
J1 Tamil on YouTube

Disclaimer

Results are for preliminary design, learning and engineering review. They don't replace the judgement of a qualified engineer. Verify final designs against project specifications, applicable codes and manufacturer data.

Questions, corrections or project enquiries: use the contact form.