Accuracy
Where Coldr's numbers come from
The sources, the curation rules, and the one thing the AI is never allowed to do.
Standards
The standards we cite
Electrical sizing uses NEC (NFPA 70) 2023, including Table 310.16 and Article 440. Gas piping uses IFGC 2024 and NFPA 54. Loads, ducts, and airflow follow ACCA Manual J and Manual D, ASHRAE Fundamentals 2021, and SMACNA. Refrigerant handling references EPA Section 608. Every calculator shows its method and assumptions on the result, and the code- and table-driven ones name the standard they draw from, so you can check the work against the book.
NEC 2023 (NFPA 70) — Table 310.16, Article 440
Conductor ampacity and wire size, MCA / MOCP for HVAC equipment.
IFGC 2024 — Tables 402.4(2) and 402.4(15)
Gas pipe sizing, schedule 40 and CSST.
NFPA 54 / ANSI Z223.1 — National Fuel Gas Code
Gas piping, altitude derate reference.
ACCA Manual J
Residential load calculation methodology.
ACCA Manual D (ANSI/ACCA 1 Manual D-2016)
Duct velocity limits, fitting losses, outlet and return sizing.
ASHRAE Handbook — Fundamentals 2021
Duct friction, psychrometrics, plenum and takeoff losses.
SMACNA HVAC Duct Construction Standards
Stock duct sizes and material roughness.
EPA Section 608 (40 CFR Part 82, Subpart F)
The refrigerant-handling reminder carried on refrigerant tools (a pre-tool gate in the mobile app).
Curation
How equipment data is curated
Model, serial, and target data come from manufacturer documents. Across two curation waves we researched 988 values, kept 824, and dropped 164 that could not be confirmed against the OEM. Fault codes (517 across 27 brands) each carry the brand document they came from; all 70 duct fittings are source-tagged; 39 values were cross-checked against a second source. When we are not sure, the field is blank.
988
researched
824
kept
164
dropped
- 27 brands, every one cited
- 70/70 fittings source-tagged
- 39 cross-checks
Review
Who reviews diagnostic thresholds
The thresholds behind the 32 guided flows — the line between normal and high superheat, acceptable and low static, a good and a weak capacitor — were reviewed and signed off by a senior technician in June 2026 (the reviewer tightened the low-superheat warning from 5°F to 8°F to catch floodback earlier). Thresholds are written as ranges with the reasoning attached; thresholds added since queue for the same sign-off before they are called authoritative.
AI
What the AI is allowed to do
The assistant (Gemini 2.5 Flash) has one cardinal rule: it may never produce an HVAC number from its training. Every figure comes from one of 71 validated tool calls — the same calculators and lookups you use directly — and every procedure or code reference cites its source from a 30-document knowledge base. If no tool can answer, it says so instead of guessing.
- Never produces an HVAC number from training — every figure is a tool result.
- Cites the knowledge-base source it used, and never fabricates a citation.
- Renders a tool's assumptions and warnings verbatim.
- Reads a nameplate or wiring photo, then answers about that exact unit.
- Says so when no tool can answer, instead of guessing.
We don't sell your data, and we don't use your content to train third-party models.
Your call
What stays your call
Coldr is assistive professional information, not engineering advice, a certified diagnosis, or a code ruling. You verify every output against the nameplate, the manufacturer's published procedures, your instruments, and the code adopted by your AHJ. Where they disagree with Coldr, they control. Refrigerant work requires your EPA 608 certification. Safety-critical decisions — refrigerant, gas, combustion, electrical — remain yours.
Report
Found a number you doubt?
Tell us. Use the feedback button in the app or write support@coldr.app with the tool, the inputs, and the source you checked against. Reported values are re-verified against the manufacturer or standard and corrected or removed. Corrections ship to web and mobile together.