Greenhouse Heating

There are many types of heating units. Choose one which will keep the temperature of your greenhouse at desired levels for the full 24 hours. With any of the nationally advertised heating systems, spare parts are easily purchased. This is a good feature as it may save you time (and thus money) in case of a breakdown.

Hot Water and Steam Heat
In cold areas, hot water systems using coal, oil, or natural gas are the most popular for greenhouses.
If you have a large enough household heating system, you may be able to pipe hot water into the greenhouse pipes. This furnishes economical heat. But if the greenhouse is very large or is located over 100 feet from the household boiler, it may be better to install a separate system.

Hot water furnishes an even, warm temperature minus the harmful fumes that are produced by some portable-type heat¬ers. With a separate hot water system, it is necessary to install a boiler. The boiler can be automatically fired with oil, stoker, or gas, thermostatically controlled, or hand-fired with coal. If it is fired by hand, it should have sufficient capacity to run for 10 or more hours without attention.
Automatic firing and thermostatically controlled tempera¬tures are a saving in time and money. They also assure more accurate heating.
If you are using coal, artificial gas, or a mixture of natural and artificial gas, the boiler must be placed in a separate room or building, since fumes from these fuels are detrimental (some¬times fatal) to plant life.
The heated water circulates through pipes or fin radiation. I have fin-type radiation. Each foot of fin radiation has several times the radiating surface of a foot of standard pipe, and much less footage is required to maintain desired temperatures. For easy calculation, 1 foot of 2-inch fin-type radiation will equal about 6 feet of standard 2-inch pipe. These figures vary with the size of the fin and the number of fins per foot. The hotter you need to keep your greenhouse, the more pipe or fin sections you should have.
Steam heat, which also utilizes piping or fin radiation, is cheaper to install but it dries out the air and the plants.