About HVAC PT Data
HVAC PT Data is a technical reference for HVAC/R technicians, engineers and trade students: refrigerant PT charts, field calculators and dated regulatory pages, built to be read on a phone at the unit.
The site exists because the basic lookups of the trade are surprisingly hard to get right online. Searches for a PT chart often return pages with rows copied wrong, a single column for a blend that needs two, or pressures several psi off. Phone apps that did the job well have been retired or stopped being updated. This site puts the charts, the calculators that use them and the rules around them in one place, with the method shown.
What is here
- Refrigerants: PT charts and master profiles for 62 refrigerants: safety class, GWP, oil, charging and status.
- Calculators: 11 tools: superheat, subcooling, target superheat, PT, glide, duct sizing, line-set charge, airflow, pressure units, psychrometrics and static pressure.
- Comparisons: Side-by-side pressures, compatibility and retrofit verdicts for common refrigerant pairs.
- A2L Transition: Rules and dates, safety classes, charge limits, detection systems, installation, codes, leak repair, recovery and cylinders.
- Field Guides: Reading PT charts, GWP, oil types, evacuation, nitrogen testing, EPA 608 certification, recovery and identifying an unknown refrigerant.
There are 62 refrigerant profiles and 11 calculators at present. Less common refrigerants are added when there is a real need for them, not to make the list longer.
How the numbers are made
No pressure, temperature or property value on this site is typed in by hand. All of them are calculated with CoolProp, an open-source implementation of the reference equations of state, by a script that writes the data files the pages are built from. Each refrigerant's chart is then compared with the manufacturer's or NIST's published values at several points, and the differences are printed on the page. The data sources and method page explains this in detail and lists every check.
The target superheat calculator uses the California Energy Commission's published Title 24 table cell for cell. Line-set charge defaults come from manufacturers' installation instructions, and the duct calculator uses the friction equations published for duct design. Each calculator page names its sources.
Regulatory and safety pages
Pages about EPA rules, A2L safety and codes are written from the Federal Register, the eCFR, EPA, ASHRAE, ICC, AHRI and manufacturer documents, and they cite them. Each page shows the date it was last reviewed, and that date changes only when the page has actually been checked again. Rules in this area changed several times between 2023 and 2026, so check the date before you rely on a statement.
What this site is not
It is a reference, not a replacement for the equipment manufacturer's installation and service instructions, local codes or your training. When a nameplate or manual gives a charging target, procedure or limit, follow it. The calculators say plainly when they cannot judge a situation, for example a TXV system on superheat alone or a superheat test outside the conditions it is valid for.
Independence and corrections
No manufacturer or distributor pays for its products to be mentioned. Trade names appear only so you can match a cylinder or a nameplate to the right chart. The site will be funded by display advertising, kept separate from the content and away from the calculator inputs and readouts.
If you find an error, a value that disagrees with a manufacturer chart, or a rule that has changed, please tell us. Corrections are made promptly and significant changes are noted on the data sources page.
The company that publishes HVAC PT Data is identified in our privacy policy. You can reach us at [email protected].