Building Ventora: An AI HVAC Assistant for Working Techs

Ampora put the NEC in an electrician's pocket. The obvious question after it shipped was whether the approach generalised, or whether we had gotten lucky with one trade.

Ventora is the answer. It is an AI HVAC assistant grounded in the International Mechanical Code, ASHRAE standards, EPA 608, and the ACCA manuals, with six field calculators built in.

What transferred cleanly

The grounding architecture. The core rule — never answer without a reference the tech can verify — is trade-agnostic. Swap the corpus, keep the discipline.

The one-handed interface. A rooftop in July and an attic in January have the same ergonomic constraints. Big targets, high contrast, minimal typing.

The calculator pattern. Both trades have a small set of calculations that get done constantly and matter enormously. Getting those exactly right, offline, is worth more than a thousand clever chat features.

What did not transfer

Here is where the "just swap the corpus" theory broke down.

Electrical code is more prescriptive than HVAC practice. The NEC gives you a table and an answer. HVAC lives in manufacturer charging charts, rules of thumb, and judgement conditioned on the equipment in front of you. Target subcooling is not in a code book — it is on the data plate.

That forced a real change. Ventora has to be explicit about deferring to the equipment. Nearly every charging answer ends with a version of "confirm against the chart on the unit."

The calculations are coupled. In electrical work, conduit fill and voltage drop are largely independent. In HVAC, airflow, charge, and load estimation are entangled — a wrong CFM reading makes a superheat diagnosis meaningless. The tools had to teach that sequence, not just compute.

Refrigerant is a moving target. Codes and blends shift. Anything hard-coded around a single refrigerant ages badly.

The six calculators

We shipped the ones techs reach for constantly:

• BTU / Load — room-by-room using ACCA Manual J methodology
• Superheat / Subcooling — by refrigerant and metering device
• Refrigerant Charge — line-set length adjustment off the factory charge
• Airflow / CFM — temperature split or duct velocity, checked against 400 CFM per ton
• Duct Sizing — Manual D, sizing a run or checking an existing one
• Hydronic / Water-Side — BTU from flow, GPM from load, pipe sizing

Every one of them runs offline. Mechanical rooms are where signal goes to die.

The lesson

The blueprint generalised, but only at the architectural level. Every trade has its own relationship with certainty, and the product has to model that relationship honestly.

Electricians want the citation. HVAC techs want the citation and an instruction to go verify against the equipment. Getting that difference wrong would have made the app feel authoritative in exactly the situations where it should not be.

Ventora is available on iOS.