Greenhouse electric heating – selection of the optimal heating system

Recommendation points

• Electric air heater
• Benefits
• disadvantages
• Infrared ceiling heaters
• Benefits
• disadvantages
• Electrical heating of the soil
• Laying heating wires
• Greenhouse Insulation Tips

In this Article: How to Heat a Home Greenhouse, Comparative Analysis of Electric Heat Transfer Fluids and Choosing the Optimal Heating System, Installation Guide for Electric Soil Heating, The Most Cost-Effective Heater, and Proper Greenhouse InsulationCommunity Q&A.

The end of winter is the beginning of a headache for gardeners who use greenhouses and greenhouses to grow seedlings and vegetables. In order for the greenhouse to function successfully, it is necessary to maintain the temperature and humidity conditions necessary for the plant. There are many ways to warm up the greenhouse, each of them has its own advantages and disadvantages..

Typically, electrical heating systems are the most popular in home greenhouses. The popularity of electric heating in greenhouses is based on economic factors that make such a system the most optimal way to achieve profit and a high yield..

The advantages of electric heating systems:

1. High efficiency and fast payback.
2. Microclimate purity (absence of gases and harmful vapors).
3. Full automation independent of human factors.
4. Reliability.

Below we will consider several popular options for electric heating and choose the most economical and optimal method for plant development..

Electric air heater

An electric heater with closed heating elements and a fan, for better circulation of warm air, as a rule, has two operating modes and is equipped with a thermostat. The power of heaters produced for greenhouses ranges from 1.1–5 kW.

Benefits

Thanks to the fan, there is continuous air circulation in the greenhouse, which significantly reduces the risk of fungal diseases in the crops grown. A sensitive thermostat allows you to adjust the microclimate required for plants with an accuracy of one degree. I would also like to note the possibility of using an electric heater as a fan. After winter frosts in the second half of spring, the solar heat, which comes from outside, is sufficient for the normal development of plants. In addition to heat, the plant needs good air circulation to avoid fungal diseases. All electric heaters produced for the needs of greenhouses are equipped with a ventilation mode without heating elements. Some modern models have two fan speed settings. Affordable price, ease of operation and automatic heating mode make the electric air heater quite profitable for use in small home greenhouses.

disadvantages

If the greenhouse is small, then one heater will do its job. With an increase in the volume of the greenhouse, it is not able to fully provide the microclimate necessary for plants. For normal circulation of warm air, it must be periodically moved to another place or another heater must be installed. An increase in the number of heaters leads to an increased consumption of electricity, which increases the total cost of vegetables grown.

Unreliability – unfortunately, not every heater model can withstand the greenhouse heating season without repair. Calling the wizard increases the overall product cost.

The main disadvantage of the air heater is the impossibility of heating the soil itself. Warm circular currents generated by the operation of the fans do not touch the ground and, accordingly, do not heat the soil and the small air gap above it. Cold soil inhibits the establishment and development of any type of plant.

But there is a way out of this situation: in order for the soil in the greenhouse to be warm, the greenhouse itself must be deepened into the ground – the lower the level, the higher the soil temperature.

You can also warm up the soil with heating wires, but we will return to them a little later..

Many greenhouses use convection heaters and tubular heating systems powered by an electric boiler. They perform their function, but their efficiency is lower than that of electric heaters.

Infrared ceiling heaters

Imagine that you have your own personal sun in a greenhouse, and then you will understand how an infrared heater works. Just like the sun, it first heats the soil, and then the surrounding air. The technical characteristics and the principle of operation of this device are described in detail in our article, so we will simply list its advantages and disadvantages.

Benefits

Energy efficiency – with low electricity consumption, a sufficiently large volume of air is heated.

Easy to install – small and lightweight for quick installation without the need for specialist assistance.

High environmental friendliness and safety – infrared heaters create natural heat that does not dry the air, the complete absence of harmful vapors and gases has a very beneficial effect on the growth and development of plants. Due to its design, the infrared heater has no causes of spontaneous combustion, which allows you to leave it unattended for a long time.

Automation – just like the heater, it is equipped with a thermostat, which increases energy savings and heating efficiency.

Reliability – high-quality components and high production technology guarantee trouble-free operation for several years.

disadvantages

High price. This disadvantage is relative, since, due to their reliability and economy, infrared heaters pay off completely in two years and work in net profit for quite a long time, unlike other types of electric heaters.

Lack of ventilation – the air circulation that occurs when using an infrared heater is not enough to ensure normal ventilation of the greenhouse, so it is advisable to install a fan. Good ventilation and air circulation is essential for any greenhouse, regardless of the type of electric heater.

Electrical heating of the soil

In order to get a harvest as soon as possible and save on heating greenhouses, it is enough to rationally use the system of electric heating of the greenhouse soil. The principle of its operation is simple: heating wires are laid in the ground, and an electric current is passed through them with the help of a step-down transformer.

Today, ready-made sets of heating wires with a thermostat are sold, which operate from 220 volts. The efficiency of heating the soil is very high, which allows you to achieve a harvest in the shortest possible time, the survival rate of plants is also very high. It is most effective to use soil heating with other types of heating.

Laying heating wires

For example, consider the installation of the Green Box Agro-400 kit, which has proven itself well when used in home greenhouses. The power consumption of such a wire is in the range of 50-90 W per m²:

1. A 25 cm soil layer is removed over the entire cultivated area of ​​the greenhouse.
2. The bottom of the resulting recess should be even, we put a protective mesh on it.
3. Maintaining a distance of 15–20 cm, we lay the wire over the entire area of ​​the pit. It is imperative to fix the heating wire with the studs included in the kit, otherwise the wire will burn out if it touches each other.
4. We fill the heating wire with sand, the layer of which should not exceed 5 cm.
5. On top of the sand we lay out a protective galvanized mesh, on top of which we throw in the excavated soil.
6. In accordance with the diagram included in the kit, we connect the wire to the thermostat, which, in turn, is connected to a 220 V circuit breaker. The connection diagram is simple and a person who has basic knowledge of physics and the basics of electrical engineering can easily handle it..

1 – soil; 2 – sand filling; 3 – protective mesh; 4 – heating wire; 5 – thermostat

The method described above is identical for all types of heating wires. If the heating wires work through a step-down transformer, then you can do without a galvanized protective mesh.

All sets of heating wires for greenhouses have an additional sheath, which serves as a screening and must be grounded without fail. Failure to observe this condition may result in an accident or even death..

Having collected all the above facts together, you can choose the most optimal heating system for home greenhouses. Criteria for choosing the optimal system: energy and maintenance costs, factors that have a beneficial effect on the development of plants, and the operating time is also taken into account in net profit after self-sufficiency. Having calculated all this, you can see the following picture. The most effective system is ceiling infrared heaters, then, with a loss of efficiency, there is: electric heating of the soil, electric heaters and tubular systems powered by a boiler with an electric heating element.

Depending on regional conditions, it makes sense to use combined heating systems, electric heating of the soil plus a heater or infrared heater..

But getting heat is not the most important task, the main thing is to preserve it and make it so that the need for it is as little as possible..

Greenhouse Insulation Tips

1. Double layer of film – an air gap between the layers will reduce heat loss by 25%.

2. Choosing the right location for the greenhouse – position the greenhouse so that the south side is completely open to sunlight. The north side must be located under the wall of some capital structure.

3. Additional insulation – at night and during severe frosts, insulate the outer walls of the greenhouse with mats or rags.

4. Layer of compost between the ground and the soil of the greenhouse – when setting up a greenhouse, it is advisable to lay out a layer of compost, and then a layer of greenhouse soil. When moisture gets in, the compost generates heat, which prevents heat exchange between the greenhouse soil and soil soil.

5. The correct selection of the heating system – when choosing, take into account the regional parameters and the temperature necessary for the favorable development of the plant.

6. In winter, to save energy during the daytime, it is rational to use mirror surfaces to reflect sunlight on the north side of the greenhouse.