Which types of greenhouse heating systems are available?
Greenhouse heating systems play an important role in horticulture. Just as in houses, greenhouses are usually heated by means of central heating. The volume of that central heating is however many times larger. In addition to central heating there are other techniques that can be applied to heat greenhouses, including a cogeneration installation, hot air heating and electrical heating. In this article we will further discuss these heating systems.
Central heating
In case of central heating warm water is directed through pipes to locations where the heat is needed. This can be done in different ways:
- Floor heating: as the name suggests, in case of floor the greenhouse is heated via the floor. This is done through pipes that are situated under the floor. Since the pipes are vulnerable to fertilizer and organic substances, they were made of polythene. The maximum water temperature for floor heating is 40 degrees C.
- Bed heating: in contrast to floor heating, when using bed heating the pipes are on the floor instead of under it. As such, the pipe radiates heat upwards as well as downwards. And that is good for the roots and the crop itself. The maximum water temperature is 40 degrees C.
- Crop heating: when applying crop heating, the pipes are hanging above the crop. This is also known as the lower net. Steel and aluminum pipes are being used for this purpose. The advantage is that the pipes can be heated to a maximum of 50 degrees C.
- Greenhouse air heating: the air in the greenhouse can also be heated via the so-called upper net, up to a maximum of 90 degrees C. The steel tubes with a 51 mm diameter are hung from a tension rod in the top of the greenhouse and are used only when the lower net has reached its maximum temperature.
- Table heating: in some cultivations, growing takes place on tables. These tables are fitted with aluminum supports. When applying table heating, polythene tubes are used to heat the aluminum supports up to 70 degrees C maximum. The supports heat the aluminum bottom on which, for example, pot plants are placed.
Cogeneration installation
A Cogeneration installation consists of two key parts; a natural gas engine and a generator. Together they generate electricity. The energy generated can subsequently be used in a smart way. Some 91% of the generated energy is actually being used. With all that energy a company can, for example, illuminate and heat its own greenhouses. In addition, the cogenerate installation develops CO2, that can be used to increase the CO2-content in the greenhouse.
Hot air heating
In contrast to central heating, hot air heating does not make use of water, but of air. Via ventilators hot air is blown into the greenhouse by hot air heaters. This hot air warms the greenhouse. A disadvantage is that the heat supply cannot be meticulously adjusted. This way of greenhouse heating is, as such, not suitable for every cultivation. Hot air heating by use of hot air heaters is often chosen when the installation of central heating or a cogeneration installation is not beneficial.
Electric heating
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Which types of greenhouse heating systems are available?
Greenhouse heating systems play an important role in horticulture. Just as in houses, greenhouses are usually heated by means of central heating. The volume of that central heating is however many times larger. In addition to central heating there are other techniques that can be applied to heat greenhouses, including a cogeneration installation, hot air heating and electrical heating. In this article we will further discuss these heating systems.
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Central heating
In case of central heating warm water is directed through pipes to locations where the heat is needed. This can be done in different ways:
- Floor heating: as the name suggests, in case of floor the greenhouse is heated via the floor. This is done through pipes that are situated under the floor. Since the pipes are vulnerable to fertilizer and organic substances, they were made of polythene. The maximum water temperature for floor heating is 40 degrees C.
- Bed heating: in contrast to floor heating, when using bed heating the pipes are on the floor instead of under it. As such, the pipe radiates heat upwards as well as downwards. And that is good for the roots and the crop itself. The maximum water temperature is 40 degrees C.
- Crop heating: when applying crop heating, the pipes are hanging above the crop. This is also known as the lower net. Steel and aluminum pipes are being used for this purpose. The advantage is that the pipes can be heated to a maximum of 50 degrees C.
- Greenhouse air heating: the air in the greenhouse can also be heated via the so-called upper net, up to a maximum of 90 degrees C. The steel tubes with a 51 mm diameter are hung from a tension rod in the top of the greenhouse and are used only when the lower net has reached its maximum temperature.
- Table heating: in some cultivations, growing takes place on tables. These tables are fitted with aluminum supports. When applying table heating, polythene tubes are used to heat the aluminum supports up to 70 degrees C maximum. The supports heat the aluminum bottom on which, for example, pot plants are placed.
Cogeneration installation
A Cogeneration installation consists of two key parts; a natural gas engine and a generator. Together they generate electricity. The energy generated can subsequently be used in a smart way. Some 91% of the generated energy is actually being used. With all that energy a company can, for example, illuminate and heat its own greenhouses. In addition, the cogenerate installation develops CO2, that can be used to increase the CO2-content in the greenhouse.
Hot air heating
In contrast to central heating, hot air heating does not make use of water, but of air. Via ventilators hot air is blown into the greenhouse by hot air heaters. This hot air warms the greenhouse. A disadvantage is that the heat supply cannot be meticulously adjusted. This way of greenhouse heating is, as such, not suitable for every cultivation. Hot air heating by use of hot air heaters is often chosen when the installation of central heating or a cogeneration installation is not beneficial.
Electric heating
Contact form
Can't find your answer? Fill out the contact form and our specialist Ben Peters will get back to you. On weekdays, even within 24 hours.
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