{
 "analysis": {
  "decile": 149.0,
  "higher_better": true,
  "label": "Smoke CADR",
  "median": 110.0,
  "pool": 68,
  "top_beats_pct": 94,
  "top_name": "Bosch Air 4000",
  "top_value": 156.0,
  "unit": "cfm"
 },
 "criteria": [
  {
   "direction": "higher",
   "key": "smoke_cadr",
   "label": "Smoke CADR",
   "unit": "cfm",
   "weight": 0.55
  },
  {
   "direction": "lower",
   "formula": "certified kWh per year x EIA U.S. average residential price x 5",
   "key": "cost5",
   "label": "5-year electricity cost",
   "unit": "USD",
   "weight": 0.45
  }
 ],
 "filters": [
  {
   "field": "ozone_emissions_ppb",
   "op": "==",
   "value": 0
  },
  {
   "field": "room_size_sq_ft",
   "op": "<=",
   "value": 250
  }
 ],
 "items": [
  {
   "brand": "Bosch",
   "id": "bosch-air-4000",
   "name": "Bosch Air 4000",
   "rank": 1,
   "score": 98.3,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4471345, retrieved 2026-11-01",
   "specs": {
    "cost5": 113.0,
    "smoke_cadr": 156.0
   }
  },
  {
   "brand": "Greenlite",
   "id": "greenlite-g-pure1-22w",
   "name": "Greenlite G-Pure1-22W",
   "rank": 2,
   "score": 97.4,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4672534, retrieved 2026-11-01",
   "specs": {
    "cost5": 117.0,
    "smoke_cadr": 158.0
   }
  },
  {
   "brand": "Midea",
   "id": "midea-kj250g-z43",
   "name": "Midea KJ250G-Z43",
   "rank": 3,
   "score": 96.2,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4439574, retrieved 2026-11-01",
   "specs": {
    "cost5": 114.0,
    "smoke_cadr": 151.0
   }
  },
  {
   "brand": "CUCKOO",
   "id": "midea-793k18a",
   "name": "Midea 793K18A",
   "rank": 4,
   "score": 95.5,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4439566, retrieved 2026-11-01",
   "specs": {
    "cost5": 114.0,
    "smoke_cadr": 149.0
   }
  },
  {
   "brand": "LEVOIT",
   "id": "levoit-lap-c341s-wusz",
   "name": "LEVOIT LAP-C341S-WUSZ",
   "rank": 5,
   "score": 93.5,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4614674, retrieved 2026-11-01",
   "specs": {
    "cost5": 132.0,
    "smoke_cadr": 161.0
   }
  },
  {
   "brand": "CLOROX",
   "id": "clorox-type-ap32-11030",
   "name": "CLOROX TYPE AP32 (11030)",
   "rank": 6,
   "score": 92.9,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4439467, retrieved 2026-11-01",
   "specs": {
    "cost5": 120.0,
    "smoke_cadr": 148.0
   }
  },
  {
   "brand": "Alen",
   "id": "alen-breathesmart-35i",
   "name": "Alen BreatheSmart 35i",
   "rank": 7,
   "score": 92.6,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4481445, retrieved 2026-11-01",
   "specs": {
    "cost5": 123.0,
    "smoke_cadr": 150.0
   }
  },
  {
   "brand": "Dreo",
   "id": "dreo-dr-hap005as",
   "name": "Dreo DR-HAP005AS",
   "rank": 8,
   "score": 90.2,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4670514, retrieved 2026-11-01",
   "specs": {
    "cost5": 133.0,
    "smoke_cadr": 152.0
   }
  },
  {
   "brand": "Honeywell",
   "id": "honeywell-hpa4200b",
   "name": "Honeywell HPA4200B",
   "rank": 9,
   "score": 90.2,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4518201, retrieved 2026-11-01",
   "specs": {
    "cost5": 124.0,
    "smoke_cadr": 144.0
   }
  },
  {
   "brand": "Longstar",
   "id": "maxlite-ap215sf4b",
   "name": "MaxLite AP215SF4B",
   "rank": 10,
   "score": 89.4,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4654774, retrieved 2026-11-01",
   "specs": {
    "cost5": 131.0,
    "smoke_cadr": 148.0
   }
  },
  {
   "brand": "Dreo",
   "id": "dreo-dr-hap007s",
   "name": "Dreo DR-HAP007S",
   "rank": 11,
   "score": 88.9,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4528733, retrieved 2026-11-01",
   "specs": {
    "cost5": 127.0,
    "smoke_cadr": 143.0
   }
  },
  {
   "brand": "Dreo",
   "id": "dreo-dr-hap009",
   "name": "Dreo DR-HAP009",
   "rank": 12,
   "score": 88.6,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4586495, retrieved 2026-11-01",
   "specs": {
    "cost5": 147.0,
    "smoke_cadr": 158.0
   }
  },
  {
   "brand": "WOOZOO",
   "id": "woozoo-apf-20",
   "name": "WOOZOO APF-20",
   "rank": 13,
   "score": 87.9,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4515996, retrieved 2026-11-01",
   "specs": {
    "cost5": 136.0,
    "smoke_cadr": 148.0
   }
  },
  {
   "brand": "Dreo",
   "id": "dreo-dr-hap007as",
   "name": "Dreo DR-HAP007AS",
   "rank": 14,
   "score": 85.7,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4577020, retrieved 2026-11-01",
   "specs": {
    "cost5": 138.0,
    "smoke_cadr": 143.0
   }
  },
  {
   "brand": "Dreo",
   "id": "dreo-dr-hap009as",
   "name": "Dreo DR-HAP009AS",
   "rank": 15,
   "score": 84.8,
   "spec_source": "ENERGY STAR certified Room Air Cleaners dataset (U.S. EPA, data.energystar.gov gaa3-swy6), record 4586614, retrieved 2026-11-01",
   "specs": {
    "cost5": 144.0,
    "smoke_cadr": 145.0
   }
  }
 ],
 "license": "https://creativecommons.org/licenses/by/4.0/",
 "method": "We kept zero-ozone ENERGY STAR air purifiers certified for rooms of 250 sq ft or less and compared those with the highest smoke CADR, weighing smoke CADR and the five-year electricity cost (certified yearly energy use x current EIA U.S. average residential price x 5). Every model tied with the last one on the selection criterion is listed, so the cut never picks among equals.",
 "name": "Best air purifiers for small rooms (up to 250 sq ft), ranked by certified data",
 "next_refresh": "2026-12-01",
 "publisher": "ByTheRank",
 "scoring": "each value scored against the best on the page (best = 1), times its weight; total out of 100",
 "selection": {
  "best": 161.0,
  "cut": 143.0,
  "label": "Smoke CADR",
  "listed": 15,
  "listings": 106,
  "merge": "listings with identical certified values on all 23 reported fields",
  "pool": 68,
  "tied_beyond_cut": 0,
  "unit": "cfm"
 },
 "sources": [
  "https://data.energystar.gov/Active-Specifications/ENERGY-STAR-Certified-Room-Air-Cleaners-V3-0/gaa3-swy6",
  "https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_5_6_a"
 ],
 "updated": "2026-11-01",
 "url": "https://bytherank.com/best-air-purifiers-for-small-rooms/",
 "why_first": {
  "criteria": [
   {
    "difference": -0.7,
    "first_points": 53.3,
    "first_value": 156.0,
    "key": "smoke_cadr",
    "label": "Smoke CADR",
    "second_points": 54.0,
    "second_value": 158.0,
    "unit": "cfm",
    "weight_pct": 55.0
   },
   {
    "difference": 1.5,
    "first_points": 45.0,
    "first_value": 113.0,
    "key": "cost5",
    "label": "5-year electricity cost",
    "second_points": 43.5,
    "second_value": 117.0,
    "unit": "USD",
    "weight_pct": 45.0
   }
  ],
  "deciding": {
   "computed": true,
   "first_value": 113.0,
   "key": "cost5",
   "label": "5-year electricity cost",
   "retrieved": "2026-11-01",
   "second_value": 117.0,
   "source": "https://data.energystar.gov/Active-Specifications/ENERGY-STAR-Certified-Room-Air-Cleaners-V3-0/gaa3-swy6"
  },
  "first": "Bosch Air 4000",
  "first_score": 98.3,
  "flip": {
   "key": "smoke_cadr",
   "label": "Smoke CADR",
   "needed_pct": 73.3,
   "now_pct": 55.0
  },
  "headline_leader": {
   "first_value": 156.0,
   "key": "smoke_cadr",
   "label": "Smoke CADR",
   "name": "LEVOIT LAP-C341S-WUSZ",
   "needed_pct": 82.3,
   "now_pct": 55.0,
   "value": 161.0
  },
  "margin": 0.9,
  "second": "Greenlite G-Pure1-22W",
  "second_score": 97.4,
  "ties": [
   {
    "names": [
     "Dreo DR-HAP005AS",
     "Honeywell HPA4200B"
    ],
    "rank": "=8",
    "rule": "equal scores share a rank; within it products are listed alphabetically (no measured difference)",
    "score": 90.2
   }
  ]
 }
}