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FieldCalc HVAC
Offline HVAC calculator: R-454B PT, superheat, duct, load
11 followers
Offline HVAC calculator: R-454B PT, superheat, duct, load
11 followers
Offline HVAC field calculator with R-454B PT charts, superheat/subcooling, duct sizing, load estimates & psychrometrics. No subscription, no ads, no tracking. Free PT charts (R-454B/R-32/R-410A) + unit converter. Pro: $9.99 one-time for all calculators, 13 refrigerants & PDF export. 100% offline — built for techs on the roof. Feedback welcome!
Offline PT charts for R-454B are exactly what I needed on a job site where the signal keeps dropping. The psychrometrics calc feels snappy and straightforward, no clutter or upsells in the way.
@merdavudoljrdf Thanks for the kind words! The "no upsells in the way" part makes me
especially happy — that was a deliberate choice. Techs need answers
fast, not a paywall popup every time they tap a button.
Out of curiosity, are you using the psychrometrics for duct design,
troubleshooting, or something else? Always interested in how people
use it in the field.
R-454B charts built in already is huge, saves me from digging through outdated pamphlets. One-time price feels right for something offline and actually built for the field.
@glenhacouljo4x Really glad to hear that — especially the R-454B part. That was the
whole reason I started building this. Digging through paper charts
on a hot roof is the worst, and every app I found was either missing
R-454B entirely or buried it behind 80 other refrigerants.
If you spot any PT values that don't match your manifold readings,
let me know and I'll verify against the source data. What refrigerants
are you working with most these days?
Really appreciate that the whole thing actually works offline. Most of these calculators want you to sign in or hit a paywall before you can even pull up a PT chart on a rooftop with no signal. Solid call building it for the people using it.
@serdar963224 Thank you! That last line means a lot — "built for the people using it"
is exactly the principle. I've watched too many techs abandon an app
because it demanded a login on a 95°F roof with zero bars.
Everything is local — no servers, no sign-in, no tracking. Just open
and calculate. If you run into anything that doesn't feel right in
the field, I'm all ears.