most efficient space heater

Milex Insta Heater Fireplace – Portable Electric Space Heater with LED Flame Effect & 3 Heat Settings, White

White-Rodgers 70 Series, 7-Day Programmable Thermostat, Heat Pump (2H/1C), 1F75H-21PR

ROVSUN 1500W Wall Heater with Remote, Freestanding & Wall-Mounted Electric Space Heater with Handle, Timer for Indoor, Bedroom

Garage/ Shop Ceiling Mount Utility Heater

ZAFRO Electric Fireplace Heater 17" , Different Flame Effects, Adjustable Brightness and Heating Mode, Overheating Safe Design

EZ Heat Portable Fireplace Fan Heater, 1200W Compact Design with Realistic Flame Effect

Optimus Portable Oscillating Ceramic w/Thermostat Heater Grey

White Rodgers Heating and Cooling Push Buttons Single Pole Thermostat

LG Electronics 12000 BTU Window Air Conditioner Heater

Pelonis 22'' Digital Convertible Ceramic Tower Heater

Bestier Electric Fireplace Heater 24.25" with Remote, Adjustable Brightness and Heating Mode, Flame Effects & Log Colors

HEATDAZ 2-Pack Air Purifier with Essential Oil Diffuser - Perfect Christmas Gift, 108 Sqft Bedroom Air Purifier & Aromatherapy, Holiday Gift Set

Portable Oscillating Fan Heater with Thermostat

Comfort Glow Electric Indoor & Outdoor All Seasons Fan and Heater With 2 heat settings

Portable Oscillating Ceramic Heater with Thermostat

Optimus Portable Oscillation Ceramic Heater w/ Thermostat & LED

Portable Utility Heater with Thermostat-Full Size

Amana 6000 BTU Window Mounted Air Conditioner and Dehumidifier: Programmable Timer, Remote, 3 Speeds, 200-500 sq. ft.

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

Heat Storm 1000W A-1000-WX-WIFI Infrared Wi-Fi Heater White

Optimus Portable 360 Surround Ceramic Heater w/ Thermostat

GDFStudio Rabun Portable Electric Fireplace Stove with Adjustable Heat

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