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.
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. Reused verbatim from the locked engine, never re-written for this page. The documents it rests on are listed in the source receipt on the tool page.
- Edition
- not a code table
- Checked
- Before any release, an automated check runs the locked engine that produces these figures and holds its answers against values written from the source it cites, so a checked number answers to its source and not merely to itself. The check covers the cases someone wrote a check for, not every input the tool accepts: it tells you where a number comes from, and it is not a proof of every value. As of the current build that suite holds 31163 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?
It computes from the sources listed in the source receipt on its tool page, and our automated checks hold its answers against values written from those sources for the cases the checks cover, not for every input you can enter. 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. Every figure an Intry calculator computes comes from a locked source module, not hand-typed. 31163 automated checks, one suite for the whole site rather than a per-tool count, re-derive the numbers before each deploy from the tables this site transcribed from the FTC 3,412 Btu/kWh and 100,000 Btu/therm constants and the RESNET defrost model it was computed from. This is our own deterministic gate, not a third-party audit. The per-tool receipt is public at https://www.intrysys.com/verified.