Methodology: pints, coverage and listing evidence
Dehumidifier shopping got harder in 2019, when the DOE test standard changed and the same machine started advertising fewer pints per day. Our answer is to score only what each exact Amazon listing states, backed by ENERGY STAR, EPA and identified manufacturer manuals. Everything here is a research summary, not a physical test.
Pints and square feet, as stated
When a listing states both a daily capacity and a coverage area with explicit units, the documented spec-fit score is 100 × [0.6 × min(stated pints per day / 120, 1) + 0.4 × min(stated coverage / 5,000 sq ft, 1)], used as the documentation component in the review blend below. We take the first value the listing states, and we flag that rating test conditions vary by seller — a 50-pint claim under the old standard is not a 50-pint claim under the new one. Listings missing either value fall back to a documentation completeness score.
Three shortlists, five listings each
Appliances, pump-feature listings and direct accessories are separated on purpose, ranked by raw editorial score after requiring captured public reviews; alphabetical sorting is an optional reader control. Amazon titles, photos and feature bullets are seller-provided evidence, displayed as claims — not laboratory performance.
Drainage and parts: exact-manual territory
Model suffixes, drain port threads, pump lift limits and replacement filter numbers must match in the exact manual. A shared brand or a similar photograph never establishes that a hose or filter fits your unit.
Review-weighted scoring
The basement-appliance index applies 100 × [0.45 × (Amazon average / 5) × min(review count / 50, 1) + 0.35 × min(log10(1 + review count) / log10(1 + 5000), 1) + 0.20 × documentation score / 100], rounded to a whole number. Captured average stars supply 45% after a confidence discount below 50 reviews, logarithmic review volume supplies 35%, and the documented pints/coverage component supplies 20%. Review popularity does not reconcile two different humidity and temperature test conditions. Nor does a seller coverage claim tell us the moisture load from seepage, laundry or an open stairwell. The raw result becomes a one-decimal score out of ten by division by ten; it is not a measured extraction rate. Ties are kept, with slug deciding only repeatable order between equal raw values, and no floor or target winner is imposed. Records lacking reviews can retain a documentation score in the catalog but do not satisfy the reviewed comparator rule above. A higher pump-model rating is not confirmation of drain lift, hose fit or continuous unattended operation: those limits belong to the exact appliance instructions.
Photos, illustrations and freshness
Amazon images appear only before their supplied expiry, never past 24 hours after retrieval; expired photos give way to a listing link. Editorial scenes are illustrations, not photographs of listed products. Price and availability pills use separately refreshed Amazon observations and are hidden after expiry. No shipping promise is inferred.
Corrections
Email the page, exact model and supporting source to [email protected]. Our affiliate disclosure explains the Amazon relationship.
Publisher-assigned rating of the first-ranked listing
On each comparison page, the first-ranked listing may display a publisher-assigned editorial rating (publisher_assigned) instead of the formula result. Elias, the publisher, assigns this value manually; it is a subjective editorial judgment, not the output of the Amazon-review formula, not an Amazon customer rating and not a physical test result. The assigned value is between 9.1 and 9.4 and is stepped from the listing's unchanged formula score: 9.4 when the raw score is 88 or more, 9.3 for 84 to 87, 9.2 for 80 to 83 and 9.1 below 80. Where the formula already yields a displayed rating above 9.0, no exception is applied and the first-ranked listing shows the formula result. Every other listing on the page shows the formula result (formula_calculated). The exception replaces only the displayed rating on its named comparison; raw scores, Amazon review evidence, shortlist eligibility and order are unchanged. Each comparison page identifies its assigned rating in its method section, and the rating badge carries a data-rating-origin attribute naming its origin.
Spec-based ratings
Products without enough customer-review data still get our rating, built only from the exact Amazon listing. We score four criteria from 0 to 10: key specifications for the product type, stated build quality, warranty and certifications, how completely the listing documents what a buyer needs, and how clearly it states fit and compatibility. The rating runs from 4.5 to 8.5: 4.5 + the average of the four × 0.4. A thin listing lowers the rating but never below 4.5, because a short listing is not proof of a poor product; the 8.5 cap means that, without customer evidence, a product cannot outrank the review-backed picks of our comparisons. These are editorial judgments from documented facts, not hands-on tests, and they are labelled "Spec-based" wherever they appear.