most efficient space heater

Karl Home 10000 BTU Wi-Fi Enabled Portable All-in-One Window Air Conditioner

SereneLife Smart Space Heater (White) – Wi-Fi Enabled, Digital Thermostat, Energy-Efficient Heater for Home and Office Use

Philips 3000 Series 7.6qt Air Fryer Black

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

Comfort Glow® QDE1250 1,500-Watt-Max Tabletop Infrared Quartz Heater with Thermostat and Remote, Black

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

ZAFRO Electric Fireplace Stove, Freestanding Electric Fireplace Heater with Adjustable Flame Brightness, Overheating Protection, 1000W/1500W,

Costway 36'' Indoor Electric Fireplace Recessed Ultra Thin Heater w/ Multicolor Flame

Cascade Portable Heater with Handle Dark Gray

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

Optimus 700-Watt Electric Portable Oil-Filled Radiator Heater

BLACK+DECKER Ceramic Oscillating Tower Heater with Remote Control, Digital LED Display, Adjustable Thermostat, 3 Heat Settings, 1500W, BHTC209, Black

Handy Heater Copper Core Tower

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

Cascade Portable Heater with Handle Black

Ninja Fireside360 Outdoor Heater & Fire Pit Black

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

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