HVAC REF PRO Professional Field Reference & Diagnostics Platform
This app is built as a high-performance, zero-latency PWA (Progressive Web App) designed specifically for the rugged demands of field service.
Here is the "under the hood" breakdown of the stack and the diagnostic logic:
🛠 The Tech Stack
- Core: React 18 + TypeScript (Strict Mode).
- Build Tool: Vite 7 (optimized for single-file deployment).
- Styling: Tailwind CSS 4.0 (using a high-contrast palette for sunlight visibility and dark-mode for mechanical rooms).
- Animations: Framer Motion (for smooth layout transitions between tools).
- State Management: Custom React Hooks + Context API (for global unit and theme persistence).
- Storage:
localStorageAPI (100% offline, zero data leaves the device). - Icons: Lucide-React (vector-based for sharp rendering on any screen).
🧊 Refrigerant Physics & P/T Logic
- Calculation Engine: Uses Linear Interpolation Algorithms across discrete datasets for 10+ refrigerants (R-410A, R-32, R-454B, etc.).
- Curve Fitting: The data points are modeled based on Refprop 10 standards to ensure sub-degree accuracy.
- Glide Management: For zeotropic blends (like R-407C), the app calculates the Mean Saturation Point and then applies a ± offset based on the specific refrigerant's glide to provide Dew Point (for superheat) and Bubble Point (for subcooling).
- Absolute Math: Compression ratios are calculated using PSIA (psig + 14.7) to ensure thermodynamic accuracy.
🧠 The Smart Diagnostic Engine
The "Pro Diagnostics" module uses a Rule-Based Expert System that analyzes the "Big Four" relationships:
- Mass Flow Check: Relationship between Suction Pressure and Superheat.
- Heat Rejection Check: Relationship between Discharge Pressure and Subcooling.
- Efficiency Check: Compression Ratio vs. Rated Amp Draw.
- Heat Exchange Check: Return/Supply Air Delta-T (Evaporator Split) and Approach Temperatures (Condenser).
Example logic flow for "Restriction Detection":
- IF Suction Pressure is LOW
- AND Superheat is HIGH
- AND Subcooling is NORMAL/HIGH
- THEN Diagnose as Liquid Line Restriction (rather than low charge).
📐 Mechanical & Electrical Tools
- Ohm's Law: Full algebraic transposition (, ) allowing any two inputs to solve the remaining two.
- Capacitor Formula: Uses the run-time formula to allow techs to check caps without disconnecting them from the circuit.
- Unit Conversions: High-precision floating-point math for converting obscure service manual units (like in. w.c. to kPa or lb to kg).
📡 Deployment Architecture
- Single-File Build: The entire app (HTML, CSS, JS, SVG assets, and Refrigerant DB) is bundled into a single file (~180KB gzipped).
- Zero-Cloud: No API calls, no login, no tracking. This makes the app instant even in deep basements or data-dead zones where traditional HVAC apps fail to load.
In short: It’s a specialized HVAC calculator wrapped in a modern web shell, engineered for speed and precision.