Diagnose with proof.
Cite the standard.
Determinari ranks the fault, shows the reasoning, and backs every reading with the standards the trade runs on — ACCA, ASHRAE, AHRI, EPA. Walk onto the call unsure; walk off certain — with a diagnosis you can defend to the customer. Real guidance under pressure: the fault call is deterministic, never an AI's guess.
Built on the standards your work is already judged by.
No invented confidence scores dressed up as physics. Determinari's guides, component library, and diagnostics cite the published references the trade actually runs on — so you can defend any call to the customer, the warranty desk, or the inspector, and train a green tech off the exact same page. This is real guidance under pressure in the field, not an AI's best guess.
Techs deserve software that respects how they actually work.
For a decade, the trades have been sold cheap, bloated software that optimizes for the back office. The field technician is treated as an afterthought—a data entry node for dispatchers.
Determinari rejects this model. We build tools that make the technician faster, safer, and more accurate — the kind of certainty you can defend to the customer, the warranty desk, or the green tech you're training.
AI never makes the fault call. It reads the data plate and finds the manual — the grunt work — while the diagnosis itself stays pure, deterministic engineering that works offline in a basement mechanical room as well as it does on a 5G connection. No black-box guessing, no telemetry-for-its-own-sake.
A free calculator hands you a number and walks away. Determinari gives you the number, the reasoning, and the published standard behind it — real guidance when you're under pressure in the field — then puts it on a report you can hand the customer. No hardware to buy first.
Engineering-grade tools for the field.
HVAC-R Diagnostic Pro
LiveThe field diagnostic platform that shows its work. Punch in your pressures from any gauge and get ranked faults with the reasoning and the standard behind every call. No probes required, and no AI guessing the fault — the diagnosis is deterministic, every time.
- P/T chart lookup & SH/SC calculation
- Deterministic confidence scoring
- Cited to ACCA, ASHRAE, AHRI & EPA standards
- Owner-authored workflow templates
- EPA 608 refrigerant tracking
- Automated service report generation
SCSH Diagnostic Tool
LiveMost field apps just look things up — SCSH computes the diagnosis. An 11-refrigerant engine names the fault, an OEM-grounded AI mentor walks the fix, and the whole job hands off clean. The deterministic technical-intelligence layer the field-service platforms don't own.
- 11-refrigerant Lee-Kesler SH/SC engine
- Diagnostic quadrant fault matrix
- Heat-pump heating-mode diagnostics
- Field calcs cited to NEC 310.16 & NFPA 54
- OEM-grounded AI mentor, sources cited
- Native iOS/Android + offline PWA
Credibility through capability.
We don't lean on testimonials or a brand name. The software earns trust through rigorous adherence to published industry standards and the real constraints of fieldwork.
Glove-friendly UI
Hit targets the first time. Oversized touch areas, high-contrast states, and deliberate layout choices designed for actual fieldwork.
A2L Refrigerant Safety
Built-in intelligence for handling next-generation slightly flammable refrigerants. Safety protocols integrated at the calculation level.
Strict EPA Compliance
2026's tighter EPA refrigerant rules pulled the tracking threshold down sharply — most commercial systems now need mandatory record-keeping just as A2L becomes the factory standard. Deterministic logging of recovered and charged refrigerant turns that into audit-ready EPA 608 documentation without a second thought.
100% Offline Capable
Mechanical rooms don't have 5G. Our calculation engines run locally on the device, syncing seamlessly only when connectivity returns.
Repeatable Field Workflows
Shop owners author step-by-step diagnostic workflows and push them to every technician. Every truck runs the same gold-standard procedure — consistency you can audit, not hope for.
Standards-Cited
Guides, the component library, and every diagnosis trace back to published industry references — ACCA, ASHRAE, AHRI, EPA. Not opinion, not a vendor's marketing. Proof you can defend.
Other tools stop short. Determinari finishes the diagnosis.
We don’t name names — but you already know the categories. Here’s where each one leaves you, and where Determinari keeps going.
Probe-locked apps
Gate the real value behind $300+ wireless probes. No probe synced, no diagnosis — and a dead Bluetooth link can stall the whole call.
Determinari: A full ranked diagnosis from manual readings — no probe to pair and no dead link to stall the call. Works with every tool brand, on any phone.
AI-guess apps
Even the new “measurement-aware” AI hands you a black-box confidence score — or a confidently wrong part — with no reasoning you can audit, cite, or defend to a customer.
Determinari: A deterministic engine shows every indicator behind the call, and the published standard behind every number. Same inputs, same answer, every time — nothing you can’t back up.
PT-chart calculators
Give you superheat and subcooling, then stop. You still interpret the fault in your head on a hot rooftop with a customer waiting.
Determinari: Carries the reading all the way to a ranked, evidence-backed fault — and the next verification step to confirm it.
Back-office field-service software
Built for dispatch, invoicing, and the office. Powerful for the calendar, but there's no diagnostic brain in the truck.
Determinari: The diagnostic layer those tools lack. Runs right alongside them — focused on the call, not the schedule.
The refrigerant transition is here. The app already speaks it.
As the industry moves to next-generation A2L refrigerants, every tech is suddenly charging and troubleshooting systems they've never touched. The PT numbers are different. The handling rules are different.
Determinari shipped R-32 and R-454B from day one — full PT libraries with linear interpolation, the same deterministic SH/SC engine, and the ASHRAE A2L class flagged automatically wherever it appears. No add-on, no update to wait for, no relearning the tool.
Walk up to an A2L system with the same certainty you have on R-410A.
Flagged as A2L (mildly flammable) automatically throughout the app — so the safety class is in front of you before you connect a hose, not buried in a spec sheet.
Built for the ecosystem.
From the individual operating out of a single van, to regional service networks, to the manufacturers themselves.
For Individual Techs
Diagnose faster and walk off every call certain. Ranked faults with the reasoning in hand mean you stop second-guessing, close the repair, and look sharp in front of the customer — no rules of thumb, no guesswork.
For Shop Owners
Fewer callbacks, consistent crews, and a measurable edge. Every tech runs the same gold-standard procedure, so a second-year diagnoses like a veteran — and benchmarking shows you how the fleet stacks up. One avoided callback pays for the seat.
For OEMs
Embed our calculation engine directly into your hardware workflows. Partner with Determinari to deliver precision diagnostics natively.
More coming.
We aren't a two-product company. We are building the definitive diagnostic suite for the physical world.
HVAC-R Diagnostic Pro Expansion
Deeper knowledge retrieval for guided repairs, plus advanced EPA 608 reporting templates.
SCSH Engine General Availability
Moving our beta multi-circuit modeling tool into production for all commercial accounts.
Predictive Acoustic Profiling
R&D phase: Localized frequency analysis for compressor wear prediction without cloud processing.