most efficient space heater

Portable Utility Heater with Thermostat-Full Size

Keystone 12000 BTU Window AC 115V Inverter Heat Cool

EZ Heat Personal Ceramic Heater and Fan w/ 1,500W Adjustable Thermostat

Optimus Portable 360 Surround Ceramic Heater w/ Thermostat

SereneLife Electric Fireplace Heater with LED Flame & Log Effects - SLFPE29WBK.5

Costway 18''Indoor Electric Fireplace Freestanding & Recessed Heater Log Flame Remote 1500W

Frigidaire Durable Oil Radiator Heater White

Heat Storm 1000W A-1000-WXG Deluxe Indoor Infrared Wall Heater Gray

Milex 360 Steam Mop ( Green )

Costway 9000 BTU Mini Split Air Conditioner & Heater with 0.75 Ton Pre-Charged Heat Pump

Costway 23'' Electric Fireplace Log Set Heater W/ Remote Control Realistic Flame 1400W

BLACK+DECKER™ 1,500-Watt-Max Infrared Quartz Tower Heater

SereneLife Electric Fireplace Heater with LED Flame & Log Effects - SLFPE36WBK.5

Heat Storm Phoenix 1500W Infrared Quartz Portable Heater

EZ Heat 1500W Baseboard Convection Heater, Adjustable Temperature with Overheat Protection

ZAFRO Electric Fireplace Log Set Heater, 21" Vintage Design Portable Freestanding Fireplace Log Heater, Realistic Flames, Overheated Protection

Optimus Electric "Flame Effect" Mini Fireplace Heater

30" Baseboard Convection Heater with Digital Display and Thermostat

Bestier Freestanding Electric Fireplace Heater with Realistic Flame & Adjustable Brightness, 1000W/1500W, Black

Costway 18" Electric Fireplace Insert 750W/1500W Fireplace Heater w/ Remote Control

Optimus 17 in. Oscillating Tower Heater w/ Remote, Digital Temperature Readout & Setting

Heat Storm 3000W In-Wall Electric Heater with Wi-Fi