Types of greenhouse heating systems

A greenhouse heating system refers to a process where the air inside a greenhouse is artificially heated to maintain a temperature that will promote the plant growth. These systems are definitely used in winters in places where the climate becomes too low to grow plants and is sometimes used in summer to maintain a certain level of heat energy within the greenhouse.

Types of greenhouse heating systems:
There are 2 main heating systems that can be adopted to maintain the required temperature in a greenhouse, namely, Centralized heating systems and local heating systems. The type of heating system to be chosen for the greenhouse depends on factors such as, size of the greenhouse, energy cost budgets, size of boiler units etc. Both the systems have their own benefits and can be automated to suit the needs of the owner as well as the plants inside the greenhouse.

1. Central Heating System: A central heating system is where the heat energy is generated using a large boiler in one location and is then distributes to many locations. These systems may distribute the heat energy either as hot water or steam. Most central heating systems use steel, copper or aluminum pipes to ensure that the hot water or steam is evenly distributed throughout the greenhouse.
2. Local Heating systems: A local heating system is located in the greenhouse or a section of the greenhouse that is responsible for heating. This type of heating system is often suggested for smaller operations and is much more cost effective as compared to a central heating system. There are various types of local heating systems. The main characteristic that differentiates them from other heating systems is that they are located inside the area that they are supposed to heat. Different kinds of local heating systems use different kinds of fuels.
3. Convection heaters: These heating systems are relatively low cost and are used in either commercial or domestic greenhouses. These systems use wood, agricultural waste or coal to produce heat. The fuel is burned in a large firebox and an exhaust is vented from the firebox into a large pipe that goes out to the greenhouse before being vented outside.
4. Solar heating: This system is only used in domestic greenhouses as the solar energy may not be sufficient for a commercial greenhouse. A major disadvantage of this heating method is that sunlight is not present at night and this causes a change in the internal temperature to the air of the greenhouse every single day and can drastically damage the plants.
5. Radiant heaters: This system refers to a structure of heaters where an aluminum tube with a reflector is used to combust fuel inside it. When the tube reaches a certain temperature, the tube emits infrared radiation which is directed downwards by the reflectors. The radiation is converted into heat when it strikes an surface like the plants or infrastructure in the greenhouse and ensures that the heat is hence maintained.
6. Unit heaters: This refers to a set of heaters that burn natural gas or agricultural wastes in a firebox through a supply line. The heat generated is transferred from the exhaust that is connected to the fire box, to the metal of the heat exchanger. A fan behind the unit draws the air inside the greenhouse to the heater and the heated air is transferred to the greenhouse.

As mentioned above, there are various types of heating systems that can be used to warm the air in a greenhouse. It is best to seek professional guidance to understand the exact need of the plants and determine which heating system is best suited for the same.