Intry Verified receipt
Is the Intry Dual-Fuel Switchover Calculator accurate?
The provenance receipt for the Intry Dual-Fuel Switchover Calculator: the exact authority its values derive from, the edition they are keyed to, who has final say, and what our automated checks hold them against, rebuilt from their cited source.
Short answer: Every figure an Intry calculator computes comes from a locked source module, not hand-typed. 27852 automated checks re-derive and source-check the numbers against the FTC 3,412 Btu/kWh and 100,000 Btu/therm constants and the RESNET defrost model it was computed from before each deploy. This is our own deterministic gate, not a third-party audit. The per-tool receipt is public at https://www.intrysys.com/verified.
The receipt
- Calculated from
- 16 CFR 305 Appendix K1 (FTC EnergyGuide), the 3,412 and 100,000 Btu constants · AHRI 210/240 rating conditions, and the defrost correction · EPA ENERGY STAR certified heat pump data (data.energystar.gov), plausibility-filtered · Manufacturer thermostat installer documentation (six brands). Reused verbatim from the locked engine, never re-written for this page.
- Checked
- Before any release, an automated check rebuilds the calculated figures from the locked engine that produces them and holds each one against the source it cites, so a number answers to its source and not merely to itself. As of the current build that suite holds 27852 checks, and this page has to clear them too. This is our own deterministic gate, not a third-party audit.
- Runnable
- A reference engine behind the published numbers on this site. Runnable access is offered on the calculators exposed at the Intry MCP endpoint.
- Final say
- The equipment manufacturer's dual-fuel guidance and the building's behavior in a cold snap have the final say. Set the lockout at or above the thermal balance point, not the economic crossover, so a cold snap never strands the load.
Frequently Asked Questions
Is the Intry Dual-Fuel Switchover Calculator accurate?
Every figure an Intry calculator computes comes from a locked source module, not hand-typed. 27852 automated checks re-derive and source-check the numbers against the FTC 3,412 Btu/kWh and 100,000 Btu/therm constants and the RESNET defrost model it was computed from before each deploy. This is our own deterministic gate, not a third-party audit. The per-tool receipt is public at https://www.intrysys.com/verified.