CLIMATE TECHNOLOGIES / EQUIPMENT

[Virtual Presenter] Good morning! Today we are here to discuss how climate technologies and equipment can be used to optimize the microclimate in greenhouses for higher production and quality, as well as better managing greenhouse design and production costs. Let's take a look at the various solutions that are available!.

[Audio] When it comes to greenhouses, controlling the microclimate is essential for optimal growth of plants. This requires a combination of heating, cooling, lighting and ventilation, but managing the energy needed for this can be costly. In the Mediterranean basin, the climate requires heating and artificial lighting in the winter, and cooling and a reduction of lighting in the summer, making it a difficult task to keep greenhouse conditions economically feasible..

[Audio] Greenhouse technology has become integral to modern farming, allowing for the regulation of microclimates within greenhouses to maximize production. The market for greenhouses in the Mediterranean basin is growing at a rate of over 3% annually through 2027, largely due to commercial and institutional investment. Similarly, the global market is also expanding due to advances in greenhouse technology and higher demand of locally-grown produce. To make the most efficient and effective use of climate technologies and equipment, it is essential to understand the distribution of greenhouses in both the global and the Mediterranean basin markets..

[Audio] Greenhouses have been revolutionized with modern climate technologies and equipment, particularly in the Netherlands. These high-tech greenhouses create the ideal environment for growing crops such as cucumbers and tomatoes either on a substrate made of stone wool or hydroponically in hanging gutters. This technology allows for the regulation of microclimates within the greenhouses, resulting in higher yields and healthier produce..

[Audio] Climate control in greenhouses can be challenging as conditions can be widely variable and require swift and precise responses. It is crucial to maintain a precise environmental control for maximum plant growth, but it can be tricky or expensive to accomplish. Externally changing temperatures and the task of regulating humidity can add complexity to the situation..

[Audio] Using technology to control microclimate in greenhouses can significantly boost output. By properly regulating temperature, humidity, light and carbon dioxide levels, production can be increased by a minimum of 30 percent. This technology is applicable to both arched and glass greenhouses, with the most important improvements seen when both light and carbon dioxide levels are managed. Farmers and agriculturalists can now get higher yields than ever before, thanks to this technology..

[Audio] Microclimate control plays an essential role in attaining maximum output from greenhouses. Spain and the Netherlands, two of the major providers of tomatoes around the world, record different costs associated with labor, capital, fertilizers, crop protection and electricity - at 5.560 Ccent/kgtruss tomatoes. This data has been supplied by the Cajamar Foundation in Spain and the Wageningen Greenhouse Horticulture in the Netherlands. By utilizing the correct technological tools, these expenses can be optimized to yield the highest production possible..

[Audio] It is quite evident that the resources used and the yields obtained for lettuce cultivation in greenhouses are much higher than those gotten in the field or in vertical farms. Specifically, water consumption in a greenhouse is 10gr per kg, compared to 20gr per kg in a field and between 80 to 120gr per kg in vertical farms. Additionally, the crop yield in greenhouses is 41 kg per m2 per year, whereas in the field it is only 250L. Not just that, the area required for 1 kg of fresh lettuce in greenhouses is also much lesser than that in fields or vertical farms. Moreover, the fresh weight per m2 per day in greenhouses is 112gr, while in the field and vertical farms it is merely 10gr and 3110gr respectively..

[Audio] Climate control technology is a critical element in modern greenhouses. To achieve optimum plant growth and quality of produce, microclimate needs to be carefully managed. This involves regulating radiation, heat, humidity, and carbon dioxide in the upper atmosphere, and water, oxygen, inorganic nutrients, and pH in the root system. Through the utilization of technology, greenhouses are able to maintain a precise level of control over these factors, while also making sure that design and production costs are kept to a minimum. These features make climate control technology an irreplaceable part of a successful greenhouse operation..

[Audio] Solar radiation plays a key role in the development of plants in greenhouses. Ultraviolet radiation, photosynthetically active radiation (PAR), and near-infrared radiation (NIR) all come from the Sun and they are necessary for plants to be able to photosynthesize and respire properly. Inside greenhouses, these radiations offer warmth, energy, and can influence the shape of plants. By accurately controlling the amount of solar radiation getting into greenhouses, we are able to achieve ideal growth as well as productive harvests..

[Audio] Plants have adapted to perform an incredible process called Photosynthesis, which unlocks energy from light to convert atmospheric carbon dioxide into biomass. Photosynthesis requires Photosynthetically Active Radiation, or PAR, in order for it to occur in greenhouses. To maximize photosynthesis rates and the overall production of plants within a greenhouse, the proper control of PAR is essential by using climate technologies and equipment..

[Audio] Photosynthesis is arguably the most impressive natural superpower. To maximize the efficiency of greenhouses, it is paramount to recognize the importance of Photosynthetically Active Radiation (PAR). The McCree Curve graphically shows which wavelengths of light are the most effective for photosynthesis, indicating that blue (350-450 nm) and red (600-700 nm) regions of the spectrum of visible light are the most useful. Consequently, it is vital to make sure the light reaching the greenhouse is full of these wavelengths in order to get the maximum benefit from the photosynthetic processes and optimize the productivity of the greenhouse..

[Audio] Solar radiation is a major factor in determining the thermal environment in a greenhouse. The cover absorbs some of the radiation, but much of it passes through the walls. Heating and cooling costs are a substantial part of the cost of cultivating plants in a greenhouse, and they can also lead to environmental concerns. Furthermore, the walls of a greenhouse are very thin and allow for 6 to 12 times more heat loss than a standard building of the same size. This can result in very high temperatures on a sunny day and low temperatures on cold nights..

[Audio] The growth of vegetables in greenhouses is heavily affected by temperature. For instance, lettuce, tomatoes, and cucumbers can develop at a quicker pace when indoor temperatures are regulated. Likewise, the rate of water evaporation is influenced by the temperature of the greenhouse, and specific instruments can be used to control the temperature and ensure optimal growth and higher produce yields..

[Audio] It is important to study the energy exchanges between the elements of a greenhouse and the outdoor space in order to understand the heating and ventilation requirements, as well as evaluate energy-saving solutions. Through these solutions, we can reduce energy costs and increase crop yields while still maintaining suitable environmental conditions..

[Audio] The energy exchanges in a greenhouse can be split into five different categories. Firstly, leakage and ventilation energy losses occur through the parts of the building that are not airtight. Secondly, conduction energy losses happen through the cover of the greenhouse. Thirdly, convection energy losses are the result of air that is warmer escaping through the cover. Fourthly, radiation energy losses occur when heat escapes through the cover in the form of solar energy. Finally, there are conduction losses from the soil to the subsoil. Other sources of energy exchange include solar radiation, the interior of the earth, plant respiration and the heating system..

[Audio] Conventional heating systems play an essential role in regulating the microclimate of greenhouses. They can either circulate hot water through pipes or utilise direct air heaters. This will keep the greenhouse's temperature close to, though slightly higher than, the desired temperature for the plants. Horizontal airflow fans are also employed to move the air and keep the temperature even throughout the area. Through the use of conventional heating systems, the ideal temperature can be assured to enable the best conditions for plant growth..

[Audio] In order to create an isothermal climate in a greenhouse, the temperature of both the indoor air and the plants must almost be identical, or slightly higher when restoring stable conditions. This balance between the environment and the plants is essential for a successful growing season. However, the greenhouse's environment tends to be slightly warmer compared to the plants. Therefore, understanding the dynamics of these systems is key..

[Audio] For conventional heating systems, an indirect heating system is capable of providing temperatures of up to 150 Watts per square meter in the air, and up to 5 to 10 Watts per square meter of energy for transpiration and heat distribution. This type of system has been incredibly successful in greenhouses all around the world..

[Audio] Conventional heating systems are widely utilized in greenhouses to maintain the preferred temperature. Heat transfer in the system can be achieved by conduction, convection and radiation. Conduction occurs when heat moves between substances in direct contact with each other. Convection is the transfer of heat through the movement of fluids. Radiation is the transfer of heat through open space. Every part of a common heating system in a greenhouse can add to energy losses. Consequently, it is essential to guarantee that the components are appropriately managed and functioning correctly to achieve an optimal energy balance in the greenhouse..

[Audio] Infrared Heating (IR) is a useful technology for providing targeted, direct heating and energy replenishment in places with low thermal insulation, such as greenhouses and livestock buildings. Using IR heating can reduce energy requirements and the environmental footprint by up to 40-50%, as it heats the plant canopy directly without needing to heat the greenhouse interior - this is known as the Cold Greenhouse concept. IR heating creates a local climate for these areas, delivering efficient heating solutions with lower energy consumption..

[Audio] Infrared heating technology plays an essential role in controlling the microclimate in greenhouses. Through exchanges of energy between the plant canopy, the indoor air, and the greenhouse cover, a uniform climate can be achieved in the area over the plant canopy. This ensures a distinct difference between the temperature of the plant (Tp), the temperature of the air (Ta), and the temperature of the cover (Tc). Because the air and cover temperatures are commonly lower than the temperature of the plants and are often unknown, this technology is crucial for maintaining the desired indoor environment..

[Audio] When dealing with microclimate control in greenhouses, energy distribution should be taken into account. According to the data, 18% of the energy goes to the leaves, 22% goes into the soil, and 25% is directed into the air. This adds up to a total of 35% of the energy, which is equal to 170 W. Additionally, 60 W m-2 is equivalent to transpiration, and infrared heating and direct heating systems are suggested to be utilized..

[Audio] Having the correct temperature in a greenhouse is an important factor in the success of crops. There are two main methods of heating greenhouses. Option (a), conventional heating, increases the air temperature within the greenhouse to the optimum temperature for the crops. However, this causes thermal stratification and higher energy losses. Option (b), infrared heating, only heats the direct area of the plant canopy, while keeping the air temperature inside the greenhouse at 3-5C lower, resulting in an energy saving of up to 40-50%..

[Audio] A comparison between a conventional and an infrared heating system was conducted to maintain an optimal climate in greenhouses with minimal energy losses. The results revealed that the energy loss values for the infrared system were significantly better than the conventional one, reducing absolute losses from the cover by up to 40-50%. This leads to a great energy savings to restore the greenhouse to its stable operating conditions..

[Audio] The distinction between heating systems is based on their energy source. Infrared heating systems are a type of conventional heating system, with their heat being carried by air, hot water, steam and/or radiation..

[Audio] Conventional Heating Systems are a popular choice for managing the climate in greenhouses. Such systems generally include a source of thermal energy, a distribution network (if using a central system), a way to dissipate the heat in the greenhouse, and various regulation and safety components. Local heating systems, where the components are situated within the greenhouse, are more common in small greenhouses..

[Audio] Fan heating is an often employed conventional heating system in greenhouses as it requires an average investment capital and can achieve a high efficiency through automation. However, it is more energy-intensive than other heating methods, and can cause the greenhouse to cool down abruptly in the event of a malfunction. Moreover, compared to a central heating system, the soil is not heated as much..

[Audio] Hot water fan heaters can be an ideal heating option for greenhouses. Boilers are used to heat water and this hot water is then circulated through large pipes which are then heated by electric fans. The airflow created by the fan heaters is used to heat up the air in the greenhouse. The fan heaters tend to be installed at a high level, as this facilitates air circulation within the greenhouse, creating the best conditions for the plants..

[Audio] Hot water fan heaters can be used to regulate temperature when controlling the microclimate in greenhouses. This type of heater uses a water-based heat exchanger and can effectively heat large areas. A virtual representation of the hot water fan heater can be used to show its location inside the greenhouse and help maintain an optimal microclimate..

[Audio] Greenhouses of today are created to provide the optimum level of microclimate for successful plant growth. Fan heaters are a key part of controlling the temperature, functioning by using gas, oil, or solid fuel. Fan heaters consist of a combustion chamber which contains an oxygen source, a heat exchanger, and a fan which circulates the air within the greenhouse. Smaller heaters draw oxygen from the air in the greenhouse for combustion, while the exhaust gases are released back into the greenhouse. As a benefit, the plants also take in the carbon dioxide emitted from these exhaust gases during daylight hours, providing it with nutrients..

[Audio] Hot air can be efficiently spread throughout larger greenhouses using plastic perforated pipes. These pipes are closed off with two sets of holes, each approximately 4-6 cm in diameter. The pipes can either be placed on the ground or hung from the ceiling, and they are connected to a fan heater that emits hot air at a high speed. This air mixes quickly with the air in the greenhouse, allowing the microclimate to be regulated and sustained without difficulty..

[Audio] Conventional heating systems use boilers to produce heat, which is then transferred to the greenhouse through heated water or steam. These boilers can be powered using a range of fuels, including LPG, oil, fuel oil, and biomas. The heat is then sent to the greenhouse through pipes, providing a controlled and comfortable environment for plants and inhabitants..

[Audio] Central heating systems can be a great way to address the heating requirements of a greenhouse. These systems are usually part of a comprehensive climate control system that includes fans and ventilators. This system ensures uniform heat distribution, temperature control and humidity regulation in large greenhouses, while still being energy efficient. Additionally, it provides a comfortable working environment for both people and plants..

[Audio] Hot water piping is a key factor to take into account when setting up a greenhouse. It is a system composed of black iron pipes, 5 cm in diameter, that spread heat throughout the greenhouse. The length of the pipes is determined according to the necessary calories and the characteristic of the pipes. The length of the pipes should be more than twice the length of the greenhouse perimeter to evenly spread the hot water, usually ranging between 85°C and 95°C, thus regulating the microclimate inside the greenhouse..

[Audio] When designing a greenhouse, placement of the distribution pipes is essential for an even distribution of heat throughout the space. The pipes should be parallel to the plant lines so they won't obstruct movement. For taller plants, orienting them in a north-south direction is advised. The central pipes, bringing in hot water from the boiler, and return pipes, collecting water from the greenhouse, are located in the outer edges. Considering all of this provides the best design for microclimate control in greenhouses..

[Audio] Greenhouse technology has made significant strides in optimizing food production. Microclimate control is an imperative factor for achieving high yields. Heat tends to dissipate faster in the peripheral area rather than the center. To maintain uniform temperature, more energy is required to be invested in the peripheral area of the greenhouse. An ideal pipe-length distribution is typically one third placed in the periphery; the remaining two thirds can be placed lower between the plants, or half between the plants and the other half on the roof. Hot water piping is one of the essential components of this system..

[Audio] Heat loss through piping is an important element to bear in mind when constructing greenhouses. It influences the energy needs of the system and, consequently, the running expenses. A table showing the thermal efficiency for each piping diameter and set up is presented. It is visible that the larger the diameter, the higher the efficiency. This is an element to consider when determining which tubing will be the best for optimal heat distribution in a greenhouse..

[Audio] Hot water piping is a great option for climate control in greenhouses. It can be set up in either a vertical or horizontal configuration and connected by a trombone system which permits precise control of temperature and humidity. This system is effective at creating a microclimate conducive for plants in conditions which otherwise would be too hostile..

[Audio] Climate control is essential to greenhouses, and hot water piping networks are a major element of this. Pipes can be installed along greenhouse poles for efficient heat transfer. Additionally, they can be placed underneath benches or pots of plants. For cut-flowers, some of the piping should be placed higher in the greenhouse to avoid water vapor condensation on them. Following these guidelines ensures desired climate control in greenhouses..

[Audio] Metal heating pipes combined with mechanical movement and placed on the ground surface in the corridor area of vegetable greenhouses offer multiple benefits. This facilitates heating the soil and root system of the plants, resulting in better temperature distribution. Further, in snow-covered areas, a few pipes placed higher to allow faster melting of snow near the gutters can protect the greenhouse from collapse and improves the thermal radiation balance of the plants..

[Audio] Climate technologies and equipment are enabling us to control the microclimate in greenhouses. Hot water piping on the ground surface combined with mechanical movements for harvesting is an example of this. This results in a more efficient way to harvest produce like tomato plants. Integrating AI-equipped robots to farms with this type of system in place provides employment solutions. This is a great contribution to advancing agriculture in many areas of the world..

[Audio] To achieve optimal microclimate control in greenhouses, it is important to prevent temperature stratification. Horizontal air flow fans are typically utilised to achieve this, reaching air flow speeds of over 12 meters per minute. This helps to ensure a better, more even temperature distribution throughout the greenhouse, thus creating better conditions for plant growth..

[Audio] Low temperature hot-water heating systems offer an effective way to control the microclimate in greenhouses. Combining water with a temperature of 20-60 °C with renewable energy sources or conventional fuels, pipes made of polyethylene and polypropylene are used to evenly distribute the heat throughout the greenhouse. These systems have the benefit of using low-cost heating elements and make it cost effective to maintain the microclimate on a year round basis..

[Audio] Low temperature hot-water heating systems are a great option for greenhouses as they provide better temperature control and energy distribution. Compared to traditional systems, the main differences are that it requires a larger heating element surface area to disperse the same amount of heat or a higher heat transfer coefficient. Moreover, the water temperature leaving the generator is lower, necessitating larger pipes to transport the increased water volume..

[Audio] Conventional heating involves the use of different fuels depending on the situation: availability, price, efficiency, and environmental impact. Among all available fuels, LPG offers more benefits due to its easy automation, lower initial cost, lack of need for storage tanks, and high efficiency rating. Following LPG are oil and fuel oil in second and third position, respectively. Nonetheless, these require more maintenance than LPG as the burner needs to be serviced every 10 days during winter..

[Audio] Infrared heating is an effective substitute for traditional methods of heating. SYSTEMA S pa - Italy, NATURAL GAS - Thessaloniki, and the Department of Agriculture at the University of Patras have successfully implemented infrared heating systems in Greek commercial greenhouses for the cultivation of seedlings and floriculture. With infrared systems, farmers can obtain more precise temperature regulation and energy savings, which enables them to make the most efficient use of natural resources in their greenhouses..

[Audio] A solution for microclimate control in greenhouses has been developed using infrared heating technology. The system uses Infra Monotube 18MI, which has a heat capacity of 45 KW each and is powered by LPG (Propane) fuel. It consists of six radiant tubes, each 18 metres long and providing 45 KW of thermal power. These tubes have been placed 3.0 metres above the plant canopy. This system has been installed in an arched greenhouse in Koropi, Attica, Greece. This type of heating system is very efficient and easy to install, so you can create the ideal microclimate in your greenhouse..

[Audio] Infrared heating systems have shown to be one of the most advantageous for greenhouses, as they are able to create more favourable temperature conditions for what is being cultivated. This is beneficial to both aiding plant growth while also lessening the probability of diseases developing. By increasing the temperature of the plants, condensation is less likely to form, thereby decreasing the humidity in the greenhouse and decreasing the chance of fungal diseases. Additionally, replacing other traditional heating systems with IR systems can slash carbon dioxide emissions by up to 50 percent, providing a variety of advantages that makes them the optimal choice for managing the climate in the greenhouse..

[Audio] Microclimate control in greenhouses requires energy cost comparisons estimated based on the area of the greenhouse, temperature difference, energy losses coefficient, and coverage material area. In this example, the power demand is 120 kW, and the cost of conventional and IR systems with hot water heating, air heating, and radiation heating energy sources such as petroleum, biomass/petroleum, and LPG-gas would be between 13.000 and 15.000 euros for a conventional system and between 10.000 and 12.000 euros for an IR system. The installation cost of the first one would be 1.500 euros, the second one 1.500 euros, and the third one 7 days. Operating costs per year for glass/PC with a conventional system range between 34.500 and 8.400/10.000 euros, and for PE (polyethylene) between 36.000 and 10.600/12.500 euros..