Greenhouse heaters can be powered by electric or gas. There are five main types used in greenhouses: natural gas heaters, space heaters (including ceramic), forced-air, hot water or steam (thermal mass), and overhead infrared (electric). Which one you choose depends on your greenhouse environment and budget.
Greenhouse heaters powered by gas do not require electricity and can be used singly or in groups and thermostatically controlled to circulate heat from the ground up. Space heaters (including ceramic) are considered a low-cost option for small greenhouses. There are gas powered and electrical options. Overhead infrared electrical heaters can be combined with soil cable heat to make a localized plant environment.
A forced-air heater is considered by some to be the best option in small greenhouse heaters. Forced-air uses a duct or plastic tube system to distribute the heat and a thermostat can be added for more control. A hot water or steam heater operates using the principle of thermal mass and with the addition of automatic ventilation makes an adequate heating system – no gas or electric required.
