Build shape
HVAC field utility app
HVAC field tool
RefriPro
An HVAC field tool that keeps PT charts, superheat/subcooling, error codes, and PDF reports in one app.
HVACOfflinePDF
Product brief
The key was not splitting calculation and reporting into separate tools, but keeping measurement and documentation in one flow.
RefriPro brings PT charts, superheat/subcooling, duct sizing, error lookup, and customer-ready PDF reports into one HVAC field app. The core idea is to keep calculations and documentation in the same workflow.
The repo shows an offline-first Flutter app with a report builder, photo and signature attachments, PDF export, job history, and multiple reference tools. It is a professional utility product shaped for field use.
Scope
Problem
Problem
Field calculations and customer documentation could not live in separate tools. The workflow had to run from measurement to paperwork.
Implementation
I built an offline-first Flutter app with PT charts, duct calculations, error codes, a report builder, photos, signatures, PDF export, and history.
Best fit
This fits professional apps for weak-signal environments where calculation and documentation need to happen together.
Technical structure
Product evidence
Primary stack
Flutter · Riverpod · GoRouter
Data & sync
Drift SQLite · PDF files · Firebase
Operational surface
AdMob · In-app purchase · photos · signatures · sharing
Stack
App client
Flutterhooks_riverpodflutter_hooksgo_routerdrift
Field calculations and reporting
PT chartsduct calculationserror code datapdfprintingsignatureshare_plus
Operations and monetization
Firebase AuthCloud FirestoreCloud FunctionsAdMobin_app_purchaseimage_picker
Integrations
Firebase AuthCloud FirestoreCloud FunctionsAdMobGoogle Play BillingPDF exportPrinting
Screens
Product evidence
App
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