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Alexander Korovaev 04/30/2020
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In central Russia, it is simply impossible to get a good harvest of heat-loving crops without greenhouses. If they are also heated, then from the beginning of March you can plant seedlings of any plants in it, and also get early greens for the table. Moreover, installing most greenhouse heating systems with your own hands is quite simple and does not require special skills.
Infrared heaters
The latest developments in greenhouse heating include ceiling-mounted infrared heaters. They consume a minimal amount of electricity, plus the effect of their action far exceeds any other types of heating devices, including water radiators and even heated floors.
Infrared heaters
The heat from them does not rise upward, but spreads evenly throughout the room. Moreover, it is the soil that warms up most intensively, and not the air, which is very important for plants.
It should be noted that to heat greenhouses it is necessary to use only long-wave devices (preferably ceramic) with heating of the working fluid to 270-300°C. Unlike medium-wave emitters, which heat up to 1700-1900°C, they are not capable of burning plants.
Significant advantages of infrared heating also include:
- environmental friendliness and harmlessness: such heaters do not emit carbon dioxide and other combustion products into the air that are harmful to plant health
- infrared devices do not dry the air at all, since they do not heat it, but any objects and surfaces; no humidification of the room is required during their installation
- no heat loss - the efficiency of such heaters is 95%
- efficiency: since they heat the soil rather than the air, the required volume of thermal resources is reduced by 35%; Plus, such devices consume a minimum of electricity
- installation of systems is simple
- the risk of fire when using infrared devices is minimized
Choosing the optimal boiler
It is necessary to select a boiler model taking into account the size of the installed greenhouse, as well as the crops being grown. If there is gas, then it is better to use gas models. For year-round models, solid fuel boilers are a good option. For small greenhouses with periodic use, installing a solid fuel boiler is not suitable. It is much more profitable to install a low-power electric one. It does not require space or the construction of a chimney, and electricity costs are minimal.
When using radiators, a number of calculations are required. To achieve a good result and maintain a constant microclimate, you should contact a specialist. In this case, the following are taken into account :
- dimensions of the building;
- thermal power ;
- number of radiators.
The sections must be distributed throughout the greenhouse in several rows. It is better to opt for low radiators for good soil heating.
Water heating using radiators Source th.decorexpro.com
Underfloor heating system
Installation of heated floors
An ideal option for heating the soil in a greenhouse is also a heated floor system. After all, for successful plant growth, it is the roots that need to be warmed up.
Since heating a greenhouse with electric heating elements will cost a lot of money, it is better to install a stove or boiler in it. The heating system can be combined by installing radiators around the perimeter.
- It is better to use polyethylene pipes to heat the greenhouse. They are buried to a depth of about 40-50 cm in the drainage - a layer of crushed stone and sand
- It is not advisable to use metal-plastic for laying in the ground. After all, its fittings (connecting elements) require regular tightening. If you still decide to use such hard plastic, use compensation loops when laying the pipeline
- The first to be laid is a polyethylene film , which serves as waterproofing.
- Next, a layer of thermal insulation made of polystyrene foam or expanded polystyrene
- You can also reduce the thermal conductivity of the soil using compacted sand , which is poured over the heat-insulating layer to a height of 10-15 cm
- The distance between the pipelines should be 0.36 m. To ensure uniform heating, 2 collectors are placed along the edges of the greenhouse. Pipes are connected to them alternately
- To protect the pipeline from damage when digging the soil with a shovel or pitchfork, slate or metal mesh is laid on top of it
- The next 35-40 cm layer is fertile soil
Heating with gas
Infrared burner
The disadvantages of such heating include the need for mandatory coordination with special services. Moreover, you will not be able to provide gas heating for the greenhouse - the design and installation of such systems is carried out only by specialists. Due to the high risk of ignition during operation, the operation of gas boilers will need to be constantly monitored. Due to the excess carbon monoxide generated during fuel combustion, ventilation .
But still, such devices have much more advantages. The cost of gas is not that high. You will only have to spend money on purchasing a boiler and equipment for it. Such designs ensure uniformity and rapid heating of the greenhouse, plus they are as easy as possible to maintain. But in order for it to heat up evenly, it is better to install heaters or connect several burners at once.
We list the main types of gas equipment used for heating greenhouses:
- convectors: industry produces special devices of this type specifically for heating greenhouses; built-in heat exchanger distributes heat evenly throughout the room; ventilation in it is provided using a coaxial (pipe in pipe) chimney
- heater with two open burners (the second of them serves as a spare) and a vertical chimney; the ventilation system is installed separately
- burners with infrared radiation: they are located in separate zones for local heating of certain types of crops or accelerating seed germination; equipped with a smoke exhauster that throws combustion products into the chimney; their operation does not require the installation of forced ventilation systems - natural is sufficient
In most cases, gas heating in greenhouses is combined with water heating . The principle of its arrangement is similar to that described above.
Heat gas gun
Heat gas gunsused for spot heating can be easily connected to both a gas main and a cylinder. Such structures are light in weight and quite mobile; they can easily be moved to any other place. The fuel in them burns completely, so the risk of carbon monoxide poisoning during their operation is minimal. Modern gas-fired heat guns are equipped with a temperature and even humidity control system.
Price issue
The easiest way to find out the exact cost and required amount of heat for a structure is to ask the manufacturer. To calculate the required power, you need to multiply the values of the total area of its glass, the heat transfer coefficient and the temperature difference. By temperature difference we mean the difference between the maximum and minimum values that are possible in a particular building. The heat transfer coefficient can be found by studying the documentation for the light-conducting material.
You can determine the most effective ways to achieve energy savings when heating by considering information about the features and location of the heated structure on the site. For example, if the greenhouse is located next to a residential building and is well insulated, you can run a heating main from the house to it by inserting a water supply hose into its channel.
In other cases, in order to save money, it is desirable to organize autonomous heating of the greenhouse using one of the methods described above.
Solar batteries
The principle of operation of a solar battery
Collecting and accumulating the heat given off by the sun's rays will help to get an early harvest in the spring. Heating a greenhouse using solar batteries can also be used as an additional option. For the winter period, the heat received only from them will not be enough.
To accumulate solar energy, the greenhouse must be installed in the most open place and located from east to west. It has been proven that arched polycarbonate structures are capable of “collecting” the maximum number of rays. Plus, the air in the cells of this material will serve as a natural heat insulator.
Solar batteries are divided into:
- water : the heat storage in this case is water containers (barrels or pools); Moreover, several small containers have a higher efficiency than one large one, because water always warms up better closer to the surface; they are distributed evenly throughout the room
- stone : this material is capable of retaining heat for a long time, so it makes sense to line the walls of the greenhouse with stone or cover it with a sufficiently large layer around the perimeter of the structure
- air : are among the most efficient battery devices (see photo); for efficient heating, heat exchangers are positioned perpendicular to the direction of the sun's rays; heated air enters the greenhouse through pipes; cold air is taken in through the second duct
When installing an air heating system in a polycarbonate greenhouse, it is advisable to use fans to ensure rapid air exchange. The inlet pipe of the air duct is located as close to the ground as possible. The pipe through which heated air enters the greenhouse is placed in the upper part of the room.
Common Mistakes
The most important mistake when heating a greenhouse with your own hands is flaws in preliminary planning. It is necessary to think through all the details in advance, calculate the costs of materials and time.
If heating work in a greenhouse is carried out in a hurry, the risk of errors increases. This leads to heat loss, malfunctions and equipment breakdowns.
There is also a risk of making mistakes in calculations and choosing the wrong boiler power for the area you plan to heat. As a result: the inability to achieve the required air temperature in the cold season. Therefore, it is recommended to consult a specialist before carrying out work.
Biological heating
Biofuel (self-heating substrate) has been used to heat plants since ancient times. Any summer resident knows that cucumbers get sick less and grow better not in open ground, but in warm manure.
Biofuel can also benefit a greenhouse. It can be used not only manure, but also plant residues, household organic waste (paper, rags, plant food residues), sawdust, leaves, straw. Later, when it completely rots and turns into humus, it is used as fertilizer. The best biofuel is obtained by mixing cow manure (1 part) with peat (3 parts). The mixture of conifer bark, sawdust and droppings heats up more slowly, so its heat lasts for a long time.
Biological heating
To heat a greenhouse using this method, it is necessary to remove the top layer of soil, lay a 15-centimeter layer of biofuel, and pour warm water over it. After a few days, when the organic mass begins to generate heat, it is again covered with removed soil and the beds are arranged.
When using straw, bales are placed in shallow ditches so that it rises slightly above the ground. To start the rotting process, the substrate is spilled with water, infusion of manure or chicken droppings. The seedlings can be planted after 2-3 days, when the temperature begins to rise.
How to heat a greenhouse with candles and bottles
This method can be useful in the event of return frosts. It allows you to increase the room temperature by several degrees in a short period of time.
When the temperature drops slightly below 0 °C, 4 candles are enough to heat a 6x3 m room . To prevent heat from immediately escaping upward, they must be covered with metal buckets, leaving a small gap between it and the ground for oxygen to enter. Buckets heated with a flame will begin to quickly heat the air.
You can replace metal buckets with ceramic pots, inserted one into the other and strung on a metal bolt. It will serve as a heat conductor.
Heating with a candle
You can also use regular water bottles to heat the greenhouse. Experienced gardeners stock up on large plastic containers and use them throughout the season. During the day, the bottles heat up in the sun, and at night, when the temperature in the greenhouse drops, they begin to release the accumulated heat into the air. Plus, in hot weather, containers with cold water save plants from excessive overheating and burns.
The best designs for greenhouse heating systems can be easily found online. For example, the author of the following video shares his own experience of heating such premises:
