What we publish
BattWise publishes calculated results and the reasoning behind them. Every figure traces back to a published source:
- IECC 2021 Table R402.1.3 for R-value targets by climate zone
- ASHRAE parallel-path method for effective assembly R-value
- heating degree days by IECC zone, and published fuel energy contents
Where a figure is a convention or a rule of thumb rather than a measurement, the page says so in those words.
How the calculations are made
The arithmetic lives in code, not in a spreadsheet and not typed into a page. That matters for two reasons: a mistake in a formula is a mistake everywhere that formula is used, and a formula in code can be tested across the whole range of inputs it will ever be asked for.
Each calculator is tested across its full input range before it goes live — for impossible values, for missing results, and for answers that contradict the explanation printed beside them. Where a calculator cannot give an honest answer for the numbers entered, it says so instead of producing a figure.
What we will not publish
We do not perform Manual J load calculations. Our HVAC sizing pages are a sanity check on a contractor quote, not a substitute for the calculation many jurisdictions require on a permit.
We also do not publish anything we cannot source. If the honest answer is "it depends on something we cannot see from here", the page says that instead of producing a number.
Corrections
If a number here is wrong, tell us at [email protected]. We would rather hear it from you than not hear it.
Corrections to a formula are fixed at the source, which means they propagate to every page that used it. Corrections to a source — a datasheet revision, a code update — are made with a note recording what changed.
Advertising
The site carries display advertising. Advertisers have no involvement in what is published, no advance sight of it and no ability to influence it. There are no sponsored placements, no paid links and no affiliate relationships.
AI and how this is written
Explanatory text on this site is drafted with AI assistance and edited before publication. The numbers are not: they are computed from the sources listed above by code that is tested, and no figure on this site is generated by a language model.
We think the distinction matters more than a blanket claim either way, so we state it plainly rather than leaving it to be guessed at.