Building Your Own Greenhouse - Storing Heat

In many greenhouse cases, heat must be stored to keep the temperature of the greenhouse as constant as possible. This is more so if plants require warmer temperatures that your location cannot provide, particularly during the winter or after the sun sets.

For storing heat, you could use water, rocks, or concrete exposing this to direct sunlight. These materials will absorb heat that you could use later. If you use bricks, tiles, or rocks remember that the darker the material is the more capacity it has for storing heat and that the heat will penetrate four inches of rocks piled on top of the other. The heat stored is then radiated throughout the greenhouse when the temperature drops. When using rocks for heat storage, use rocks that are about + to 1 + inches in diameter as it has better surface area ratio. Pile the rocks in a wire mesh to contain them.

If you want to use water to store heat, use ordinary 55-gallon drums. Paint the drum dark and fill with water placed in strategic locations inside the greenhouse. Water absorbs and disperses heat that is ideal for greenhouse use. You could use smaller jugs and water containers. Smaller water containers are even more effective than large water drums due to its higher surface ratio that enables it to absorb heat faster. Plastic containers are good except that it degrades after a few years in contrast to glass water jugs.

Using trombe wall are also efficient ways of storing heat. If a trombe wall is required for heat storage, construct the walls facing the southern side of the greenhouse to absorb the most heat during the day. You will need about six inches of masonry constructed outside the greenhouse, connected to one of its walls. Coat the wall with a dark color to maximize its ability to retain heat. The heat conserved inside the trombe wall is then radiated into the greenhouse through small outlets in the greenhouse wall. The trombe wall is very useful especially during drops in temperature.

A variation of the trombe wall is the water wall. While the trombe wall uses masonry to store heat the water wall use water containers and water bags instead. The water-filled bags are placed between the working space and the glazing inside the greenhouse but are exposed directly in the sun's rays. The water inside the tubes, jugs and containers absorbs the heat and is dispersed slowly throughout the night.