How we verify specs and prices

Specs and prices run on separate tracks, because the documents that carry one never carry the other. For specs, three document classes count as sources; nothing else does. In order of authority:

1. The AHRI Directory of Certified Product Performance, the filing of record for capacity and efficiency ratings.
2. Manufacturer engineering documents: spec sheets, submittal sheets, service manuals, and warranty PDFs, cited by revision.
3. The NEEP cold-climate directory, for capacity-at-temperature points.

Retailer listings, press releases, and marketing pages are never sources for specs. They are sources only for prices, and only with the retailer and the date checked named on the page. A cost guide never backs a spec figure, and a spec sheet never backs a price.

Every published figure resolves to a dated row in our source register before it ships. Forum and review-site anecdotes validate topics and phrasing; they are never a source for a figure.

Every spec and price renders with the month we last checked it against its source, the "verified Aug 2026" mark you see across the site. On this site a spec without a date is a build error: the page will not publish.

When two sources disagree, we do not pick the flattering number. We publish both values side by side with their sources, use the filing of record in our tables, and say so on the page.

We do not estimate specs. No interpolating capacity between rated temperature points, no converting SEER to SEER2 by formula, no deriving amperage from BTU. A figure we could not verify is marked unverified or omitted, never guessed. A price older than six months is re-checked or removed before the page is otherwise edited.

The tier describes the refrigerant line set and the warranty's install clause, never our opinion of your skills.

Prices name the retailer and the date checked, always, and say what the number includes: equipment only is not an installed cost, and we never derive one from the other. Once an affiliate program approves us we may earn a commission on some links; every verdict is set before any link is added, and pages will recommend against units we could earn on. Buttons say "Check price at [merchant]"; we do not do urgency. The full terms are in the affiliate disclosure.

Found a figure that does not match its source? Tell us through the contact page with the page and the document. Verified errors are fixed within 72 hours, dated in a correction note on the page, and the reader is credited unless they ask otherwise.

The mini split BTU calculator is a hybrid, and we separate the two halves on purpose. One half is a published table we did not write. The other half is our own judgement. You should be able to tell which is which before you trust a number.

Cooling: a cited base

The cooling base is ENERGY STAR's published area-to-capacity table for room air conditioners, used verbatim. It runs from 100 ft² (5,000 BTU) to 2,500 ft² (34,000 BTU); we cap our own use of it at 1,400 ft². ENERGY STAR states the table assumes an 8 ft ceiling. Sun exposure is theirs too: reduce capacity 10% for a heavily shaded room, increase it 10% for a very sunny one. We do not adjust these numbers. The page is captured in our research corpus and registered with its access date, like any other source we cite.

The modifiers: ours, and labelled as ours

Ceiling height (8 ft ×1.00, 9 ft ×1.06, 10 ft ×1.12, 12 ft or more ×1.25), insulation (good ×0.85, average ×1.00, poor ×1.30), and climate zone (cooling ×0.90 to ×1.15 across zones 6-7 to 1-2) are MiniSplitsHQ editorial factors. No Tier-1 published table covers them for mini-splits. They are screening judgement, not a standard, and we do not attribute them to ACCA, ENERGY STAR, or anyone else. Cooling applies them in that order on top of the ENERGY STAR base, then the sun adjustment.

Heating: an editorial load, and where it stops

The heating figure is also ours: 24 BTU per ft², adjusted by ceiling height, insulation, and a climate-zone heating factor (×0.60 in zones 1-2 up to ×1.40 in zones 6-7). It is a load — the heat the room needs at 5°F — and that is where we stop.

Why we do not convert heating into a unit size

We used to. A single factor turned the load into a nameplate rating, and it was wrong to do so, because real capacity at 5°F varies far too much between models for one number to describe it. Among 12,000 BTU units in our own verified spec set: a budget model makes 6,600 BTU at 5°F, a cold-climate model holds 13,500, and another reaches 16,600. Any single conversion factor would badly misprice most of that range. So the calculator hands you the load and names the real step: compare it against a specific model's verified 5°F capacity from NEEP or AHRI, not against the number on its box. Cooling still maps to a purchasable class (6,000, 9,000, 12,000, 18,000, 24,000, 36,000 BTU), always rounding up, because no unit is sold between those sizes.

Where the calculator stops

Above 1,400 ft², or once either figure passes 36,000 BTU, the calculator declines to give a number and points at a Manual J load calculation instead. In a cold zone with poor insulation that bound arrives well before 1,400 ft². Rule-of-thumb sizing is for narrowing the field; a Manual J, which measures your walls, windows, and orientation, is what a final equipment decision should rest on.

Research, document diffing, and drafting are done with AI assistance. A human editor reviews every page before publish and owns every verdict. The verification dates are real: they record when the figure was confirmed against the source document. The fuller standard is in the editorial policy.