most efficient space heater

Comfort Glow® EFH1518 1,500-Watt-Max Portable Electric Fan Heater with Thermostat, White

Optimus 700-Watt Electric Portable Oil-Filled Radiator Heater

Emerald Compact & Portable, 1000W Electric Single Burner 6.1" Coil Less Plate Stovetop

R.W.FLAME 17" Electric Fireplace with Remote, Cathedral Design, Adjustable Flames, Brightness, Heat, and Overheat Protection

Handy Heater Copper Core Tower

BLACK+DECKER™ 1,500-Watt-Max Personal Desktop Heater with Fan Setting in White

Whirlpool 6000 BTU 115V Window Mounted Air Conditioner and Dehumidifier: 3 Speeds, 8-Way Air Control, 200-500 sq. ft.

Vie Air 1500W Portable 2 Settings Black Ceramic Heater with Adjustable Thermostat

Frigidaire Portable Neck Heater Black

ZAFRO Electric Fireplace Log Set Heater, 21" Vintage Design Portable Freestanding Fireplace Log Heater,Realistic Flames,Realistic Ember Bed for Home

LP500APHTR LivePure 2 in 1 Clean Heat Air Purifier & Heater

Cascade Portable Heater with Handle Slate

BLACK+DECKER Window Air Conditioner, White

Cascade Portable Heater with Handle Goldenrod

Costway 1500W Electric Indoor Oil Heater W/3 Heat Settings & Safe Protection for Home

BLACK+DECKER Electronic Heater with E-Saver Function

HEATDAZ Smart Air Purifier - Perfect Christmas Gift, WiFi with PM2.5 Sensor & Sleep Mode, HEPA Filter for 2050 SqFt Home

Optimus Fan Forced Tower Quartz Heater with Thermostat

Dan’s Originals for Lasko 2033624 Space Heater Remote Control - 2033624