STC EGH520 Portable Greenhouse Heater (Discontinued by Manufacturer) Portable greenhouse heater is perfect for small spaces Generates 5,120 BTU and will heat up to 120 square feet of space Two heat settings and a fan-only setting Includes a 6-foot cord with a 3-prong NEMA plug Measures 10.5 Inch by 6.5 Inch by 15 Inch