Our mushroom heaters are great for patios, decks and open areas. They are not allowed to be used in tents or inside buildings. If you need tent heating solutions our duct heaters are the answer. Please ask your A-1 Rentals Representative for proper guidance on the sizes and amounts of heaters needed. Price includes a 20 pound propane tank. The propane tank can last up to 8 hours. It depends on the heater setting and ambient temperature. Each patio heater generally heats up a 100 sq.ft. area. Hi winds will lower the effectiveness of the heater.