Space Heater Companies methodology

Scope

Companies with a current United States portfolio of portable household electric space heaters, assessed through representative ceramic, fan-forced, oil-filled radiator, infrared or radiant, and smart-capable models. The ranked unit is the company, not a single model.

Choose a company whose current portable electric heaters offer independently supported room-heating performance, strong safety controls, practical temperature management, value, and support for a United States household.

Evidence standard

Material score inputs must resolve through a public claim and evidence record to an admissible source. Primary documentation supports specifications and policies; credible independent evidence is used for performance or experiential claims when available. AI output and search snippets are not ranking evidence.

Missing and conflicting evidence

Missing evidence is never guessed or silently reweighted. A predeclared category rule may handle a verified absence; otherwise the score remains incomplete. Conflicting source evidence stays visible, can reduce confidence, and blocks an input when unresolved.

Coverage and confidence

Evidence coverage measures how much of the frozen rubric has admissible support. Confidence reflects source strength, freshness, corroboration, and source-conflict status. Neither measure adds points to the organic score.

Deterministic scoring, rounding, and ties

Scores use the frozen weights above and full-precision deterministic arithmetic. Public scores use one decimal place, but rank order uses the unrounded value. Remaining ties use competition ranking and are never broken by editorial preference.

Versions and corrections

This page describes Version 1.0 of the methodology for Version 1.0 of this ranking. A material evidence or scoring change creates a successor version; prior published history is not silently overwritten.

The primary public ranking displays at most the Top 10 qualified companies. Complete evaluated results and immutable rank history remain in canonical data; scores are never changed to fill or enter the public list.