HVAC Calculator – LIB Toolkit
Field-ready HVAC and electrical calculations, made by HVAC contractors. Built by Legacy International, an HVAC and electrical contractor in Oman since 2008, for the calculations technicians and engineers do every day on site.
What it does
One app for the numbers you need on site, from a quick estimate to a full calculation and a signed job card.
Cooling load
From a quick estimate to a detailed room calculation.
Heating and heat pumps
Heat loss at your winter low, and the backup heat you need.
Electrical
Breaker, cable or wire size and voltage drop. BS 7671 and IEC rules, and the NEC with AWG sizes for the US.
Gas check
Pressure-temperature charts for 12 refrigerants including R-454B and R-32, plus superheat and subcooling.
Ducts, pipes and more
Ducts, pipes, ventilation, VRF and motors.
Job cards
Professional service reports with your letterhead, stamp and signature, saved as PDF.
Design weather from your location
Summer peak, humidity and winter low for where you work.
See it in action
Clear results, simple inputs, and a job card ready to print or share.
Works your way
Choose your region and the app sets units, codes, voltages, refrigerants, currency and paper size to match.
- USA
- UK
- Europe
- Gulf (GCC)
- Other countries
Free and Pro
Free
USD 0
The core tools and 5 job cards.
Pro
One-time payment
Unlocks everything, with no subscription.
Your data stays on your phone
There are no accounts, ads or tracking. Read the privacy policy.