The greenhouse makes it possible to harvest regardless of the season. And to create optimal conditions for each crop, it is necessary to take into account the climate, the composition of the material from which the greenhouse is made, the area of the greenhouse. And based on the data obtained, choose the type of heating. In this article, we will analyze all the heating methods, their advantages and disadvantages.
Types of greenhouse heating
Solar heating is the easiest and most budget option. Heating occurs naturally and heat is released gradually, this effect is achieved due to the greenhouse effect, this method directly depends on the climate and weather conditions, so temperature adjustment is impossible.
Such a greenhouse, in this case a greenhouse, should be made of polycarbonate, since such material provides an increased greenhouse effect compared to other substances. An alternative would be glass that transmits over 95% of the light flux. The disadvantages of this method are the need to create an arched structure, as well as strictly orient the greenhouse along the axis from east to west.
The peculiarity of the biological method is that biofuel is laid under the fertile layer, which warms up the earth due to natural decomposition processes, the heat is released gradually. Due to it, less fertilizing and watering is required. As a biofuel, horse manure is often used, which can warm up to 70 degrees in 7 days and can maintain this temperature for several months. If very powerful heating is not needed, manure is mixed with straw. Less powerful methods are the use of sawdust, tree bark and food waste.
Gas heating has a relative efficiency and simplicity of the system, and the air warms up quickly and evenly, the possibility of creating it from factory components – these are the main positive aspects. However, it will be necessary, along with an accurate calculation, to prepare drawings and a package of permits. It is impossible to implement the project without the consent of the registering state bodies, and each alteration of it entails new costs. If your site is fully gasified, then you should not have problems with the installation.
To heat the greenhouse, it uses a system of gas heaters or burners, which are evenly distributed around the perimeter of the heated room. If the greenhouse is small, then gas cylinders can be used as a heat source, while for large heated areas, it will be necessary to resort to a centralized connection of the greenhouse to the main gasification system. Gas heating has a number of disadvantages: firstly, natural gas is explosive and toxic. Secondly, when it is used in a greenhouse, excess humidity appears, and the concentration of carbon dioxide increases several times. For this type of heating, ventilation is required, which also requires additional calculation, and in winter, the supply of fresh air devalues the generated energy.
Electric heating is quite efficient and does not require significant costs. According to experts, the best way to work is to use infrared heat sources, which do not waste energy on heating the air, directly transferring it to the soil and plants. However, such a solution has a technical difficulty: it is impossible to do everything properly without the help of qualified installers. But you can vary the heating in different parts of the room, creating the most attractive conditions for each group of crops.
Water heating is well suited for large greenhouses, and it allows you to give off heat both to the soil and to the air. This option can be implemented in several ways: installing a separate boiler or connecting to a house system. In another case, a separate circuit is made to turn it off and drain the water. If a separate system is being installed, then the boiler must be installed taking into account the available and profitable fuel.
Gas models are the most convenient and economical, allow you to maintain the desired temperature. Combustion products are removed using a coaxial chimney. Solid fuel models may have different modifications. Also an economical option, but there is practically no possibility of automation and constant monitoring is required. Electric models that maintain the temperature around the clock have high automation indicators. They are compact in size, safe and silent, but the cost of electricity is high. In addition to the boiler itself, it is also necessary to install pipelines and radiators associated with them. Also important are expansion tanks, chimneys and circulation pumps. It is recommended to form a pair of heating circuits, and not one. One line is being built underground, which is made of plastic pipes that serve to migrate water with a temperature of about +30 degrees. Such pipes should be laid as close to the roots as possible.
A fairly simple and budgetary way to maintain the desired temperature in a greenhouse is the presence of a “warm floor”, which is used to heat the soil. Such a soil heating system in a greenhouse is quite budgetary both at the installation stage and at the operation stage. In addition, it has the ability to automatically regulate heating and evenly distribute heat throughout the greenhouse.
The design is quite simple. The most popular system is the waterproof heating mat. To create a “warm floor” in the greenhouse, up to 40 cm of soil is removed, and pre-sifted sand is poured into the bottom of the recess with a layer of 5-10 cm. Next, a heater (polystyrene foam, polyethylene foam, etc.) is laid in the recess. We select materials resistant to moisture. The next layer is laid waterproofing material. Sand is poured on top with a layer of 5 cm. Everything is moistened with water and rammed. The wire of the “warm floor” is laid with a snake over the compacted sand with a step of 15 cm. The finished heating system is again covered with a 5-10 cm layer of sand, on which a chain-link mesh is laid. Next, the “pie” is covered with previously removed soil.
Another fairly popular and budgetary way of heating is with a stove, or rather a potbelly stove, which is able to maintain a temperature of about 18-24 ° C for quite a long time.
As already mentioned, this method of heating is economical and simple. The price of fuel for a potbelly stove is moderate, and its installation can be done independently, without the help of specialists. Also, after kindling with firewood, sawdust, packaging materials or rags, after them an excellent fertilizer is obtained for feeding the soil – ash. However, the main disadvantage of using the stove in a greenhouse is that the air does not always warm up evenly: it is too hot near the stove and the plants planted in this area will die from the wrong temperature. Do not forget that the potbelly stove is a fire hazardous design, and therefore requires compliance with safety rules. In addition, for the quality work of the potbelly stove, it is necessary to regularly throw fuel into it, in other words, to be in the greenhouse all the time.
How to choose the type of heating?
Regardless of what you decide to heat the building with wood or electricity, you first need to calculate the amount of heat needed for it. In addition, you need to have data on the lowest daily temperature for your area, and the average wind speed during that day. This information can be found in the standard called “Construction climatology and geophysics”. A calculator for calculating the amount in a greenhouse can be found on the net. It is worth considering the specifics of the material from which the greenhouses are made for high-quality selection of heating.
For example, heating film greenhouses, for example, requires more heat than heating greenhouses made of polycarbonate, a material that itself is a good heat insulator. It is necessary to take into account the features of the system. For example, some of them, due to their high cost, are not suitable for small greenhouses. Other systems require professional installation and configuration. This is especially important when it comes to heating industrial greenhouses, where advanced technologies are used, such as heat pumps, infrared heating and others. And be sure to consult with experts on all issues. Any slightest mistake can lead to a sad result – a poor harvest and slow development of plants.