Greenhouse Heating Methods
- A greenhouse keeps plants growing year round, but it must be heated in the winter.Metal greenhouse in summer with open door image by Scott Latham from Fotolia.com
When the weather gets colder you want to find a way to heat your greenhouse and keep your precious plants healthy and growing. Fortunately there are several methods available to you. These methods include simple low-cost, low-output solutions for mild winters to high-cost, high-output solutions for regions where winters can be harsh. - Shop lights are an effective way to produce heat for your greenhouse because most of the energy produced by these type of lights is heat. To use shop lights to heat your greenhouse you must position them throughout the building. Make sure the lights aren't too close to plants because the direct heat may kill some species. Shop lights are very effective in mildly cold weather but in very cold weather you must consider another heating source.
- Water drums are by far the most economical way to heat a greenhouse. For this method you must paint 55-gallon drums or large steel trashcans black. Position the trashcans or drums on the side of your greenhouse where the sun will hit them all day. Once you have the drums in position, fill them with water and replace the lid. The sun will heat the drums all day and the drums will radiate heat throughout the night. This method will work for mildly cold nights and is the most cost effective heating method.
- Space heaters work well to heat a small greenhouse in very cold weather. Space heaters consume between 1500 and 3000 watts of power. The advantage of space heaters is their low cost, which enables you add multiple space heaters to either generate more heat or to heat a larger area. Space heater are less economical then either shop lights or water drums but by using a space heater you may effectively heat your greenhouse even if the weather is very cold.
- A greenhouse heater is the most effective way of heating your greenhouse when you are dealing with very cold temperatures. A greenhouse heater also is the most expensive way to heat your green house, both because of the initial cost of the unit and because you must integrate it properly into the structure for it to operate safely and effectively. Greenhouse heaters use either electricity or gas. For gas heaters it is critical that you provide a way for fresh air to get inside the greenhouse and a way for gases to escape from the heater to outside air.
