most efficient space heater

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

JIONJOY 26" Electric Fireplace Heater - Freestanding Stove with 3D Flame Effect

Kismile Electric Fireplace, Realistic Flame Effects Fireplace Heater Stove, Adjustable Brightness and Heating Mode, Overheating Safe Design (Black)

Portable Oscillating Ceramic Heater with Thermostat

Costway 25''Electric Fireplace Freestanding & Recessed Heater Log Flame Remote 1350W

Optimus Fan Forced Tower Quartz Heater with Thermostat

EAGLE PEAK 1500W Indoor Heater with Thermostat, IPX 4 Splash-proof, Overheat Protection, Radiant Heating

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

Mydepot 19” Freestanding Electric Fireplace Heater Black

VOLTORB 3-Sided Flame View Infrared Quartz Heater Stove, Free Standing Electric Fireplace for Indoor Use w/Remote Control & Programmable Timer, Black

Pelonis Portable Ceramic Electric Oscillating Fan Space Heater, White

Portable Space Heater with Handle, 2-Speed PTC Fast Heating Ceramic Heater, 1500W/750W for Indoor Desk & Personal Use

Garage/ Shop Ceiling Mount Utility Heater

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

Kismile 21" Electric Fireplace Logs Set Heater,Realistic Flames, Overheated Protection, Realistic Ember Bed for Home and Office, 750W/1500W

LG Electronics 12000 BTU Window Air Conditioner Heater