In today’s world, with limited fuel reserves and humanity’s growing need for energy, fuel prices are constantly on the rise. This increasingly highlights the need to use new and optimal technologies in every field. Greenhouse owners and plant growers are no exception to this rule and are always seeking to increase their productivity and product quality through the use of modern technologies. In this context, heating greenhouses with a greenhouse radiant heater or greenhouse radiant heating system has become one of the best methods for providing greenhouse heating, and it has gained increasing popularity in recent years. This system, inspired by nature and the sun’s heating performance, has shown high efficiency and effectiveness in heating industrial greenhouses since the 1970s.
What Is a Greenhouse Radiant Heater and How Does It Work?
A radiant heater provides heat uniformly with minimal energy consumption through radiant heat transfer. Unlike traditional methods that rely on heating the air in a greenhouse, a greenhouse radiant heater offers a different approach. In traditional methods, such as unit heaters, furnaces, and jet fans, the heated air becomes lighter and accumulates under the greenhouse roof. This causes a significant increase in temperature under the roof, leading to heat exchange with the outside and increased heat loss. Due to the high humidity in greenhouses, this issue causes condensation and water droplets to fall from the roof, as well as dew on the plant surfaces, which leads to an increase in pests and diseases. Furthermore, in these methods, the temperature of the soil surface is not adequately maintained.
In a greenhouse radiant heater system, however, heat is transferred through infrared waves. These waves, after striking the plant surface and its bed, are absorbed and converted into heat. Radiant thermal energy does not turn into heat until it is absorbed by an object and is directed toward the objects that need to be warmed. For this reason, the temperature under the greenhouse roof does not increase much, and heat loss from the roof is drastically reduced, which results in substantial fuel savings. Radiant heating provides warmth similar to the heat from the sun. In this scenario, the temperature of the soil and plant surfaces is slightly higher than the air temperature in the greenhouse.
Unique Advantages of Greenhouse Radiant Heating
The radiant heating system offers numerous advantages compared to common heating systems. These benefits have made the radiant heater (also known as a tubular heater) one of the best and most optimal options for greenhouse radiant heating:
Significant Energy Savings (Gas and Electricity)
- At least 50% reduction in fuel (gas) consumption: These devices convert fuel (natural gas or diesel) into radiant heat with very high efficiency. This allows the heat transfer to be directed to the floor of the hall, providing a uniform and balanced heat distribution.
- At least 90% reduction in electricity consumption: The absence of a blowing fan in the greenhouse radiant heater is one of the main reasons for its lower electricity consumption.
- Reduced energy loss: The temperature of the soil and plants is fundamentally about 0.7 degrees Celsius warmer than the ambient air temperature. This temperature difference prevents heat stratification (colder at the bottom, warmer at the top) in the greenhouse, keeping the temperature uniform from the soil level upwards. According to the ASHRAE standard, heat loss in halls equipped with a greenhouse radiant heating system is 15% to 20% less.
Providing an Optimal Environment for Plant Health and Growth
- Optimal heating of the soil and plant roots: Radiant thermal energy is directed downward to the soil and plants. This causes the soil to warm up with the help of the greenhouse radiant heater, activating the roots and helping the plant grow faster.
- Significant reduction in diseases: Wetness on plants (free moisture on the plant surface) is the main cause of many diseases, such as fungal spots, gray mold, downy mildew, and root rot, which are completely eliminated by greenhouse radiant heating. This system removes the environmental factor that causes diseases.
- Uniform plant temperature day and night: Since the plant and soil are heated directly (not just the air), the plant’s temperature will be higher than the surrounding air day and night, similar to the effect of the sun. This eliminates destructive temperature fluctuations for plants and reduces thermal shock caused by turning off the greenhouse radiant heater system due to the large thermal source present in the soil and plants.
- Optimal air quality: Due to the lack of air movement in the greenhouse, the air quality is very good, and the need for a high rate of fresh air intake is greatly reduced.
- Quick drying of cement walkways: The use of greenhouse radiant heating on the floor causes the walkways to dry quickly, as they also absorb the heat and dry out rapidly.
Operational Benefits and Easy Installation
- No Loss of Usable Space: Greenhouse radiant heaters are installed at a height, so they don’t take up any physical space on the floor of the hall.
- Precise Temperature Control: Controlling the plants’ temperature becomes easy and precise because the temperature measurement device receives the same radiant heat that the plants do. It’s possible to install thermostats on Dadman Tahvieh‘s devices. With proper design and installation, a temperature difference of less than 0.5 degrees Celsius can be achieved across 95% of the greenhouse area.
- Fast Heating: The space heats up quickly. As soon as the burner is turned on, the tubes heat up rapidly, and the resulting radiant heat can be felt within minutes. This is much faster than air heating systems.
- High Reliability from Multiple Burners: Unlike traditional systems that have one or two burners, each greenhouse radiant heater has its own separate burner. Therefore, if one burner stops working, the others will continue to operate.
- Effective Use of Entire Space: The uniform heating increases the suitable area for growing plants, as even the sides and far corners of the walls are well-heated. Greenhouse radiant heating makes it possible to grow multiple layers of plants from the floor to the ceiling of the greenhouse at a uniform temperature.
Reduced Maintenance Costs
- Lower Investment: Compared to engine rooms and hot water or steam piping, a greenhouse radiant heater requires less investment.
- Return on Investment in Approximately 2 Years: All costs for purchasing the devices are recovered through reduced gas and electricity consumption, typically within two years.
- Prevents Theft and Tampering: Because the heaters are installed at a height, there is less chance of theft or tampering by unauthorized people.
Important Tips for Choosing and Maintaining a Greenhouse Radiant Heating System
Choosing a safe and high-quality greenhouse radiant heating system is one of the most important factors in building and outfitting a greenhouse. To choose the most suitable radiant heater system for your greenhouse, you should consider the following:
- The Plants’ Temperature Needs: First, you must determine the required temperature for the plants you are cultivating in the greenhouse.
- Dimensions and Structure of the Greenhouse: The area and dimensions of the greenhouse hall are very important. The larger the space, the higher the heating capacity required from a greenhouse radiant heater to warm it and keep the temperature uniform. The type of covering and insulation of the greenhouse’s structure (roof, walls, seals) also has a direct effect on the required heating capacity calculations, and proper insulation can drastically reduce energy consumption.
- Fuel Type and Budget.
- External Environmental Conditions: Knowing the temperature conditions outside the greenhouse is also an important factor.
- Number and Capacity of Devices: The number and heating capacity of the devices are related to the dimensions and area of the greenhouse, and can vary from one to dozens of units.
Maintenance of Dadman Tahvieh Heating Systems
At the beginning of the cold season, it’s recommended that greenhouse owners schedule service and maintenance for their radiant heaters to ensure the devices are operating correctly and that all of them are working. Every gas-fired appliance requires annual servicing to check its safety and performance. This includes checking the burner and flame quality, inspecting the exhaust of combustion products and the fan’s performance, and cleaning the reflectors to optimize heat radiation. The Dadman Tahvieh greenhouse radiant heater system has simple maintenance instructions and few components that are easily visible and inspectable. This makes them less prone to breakdowns and easier to troubleshoot and repair.
Free Design and Services
The design of a greenhouse heating system is performed free of charge by the company Dadman Tahvieh. Additionally, free on-site visits and consultations are also offered. For this purpose, please get in touch with our experts.
Other Dadman Tahvieh Radiant Heater Products
- Radiant Heater for Dairy and Cattle Farms
- Radiant Heater for Poultry Farms
- Industrial Electric Radiant Heater
- Heating for Sports Halls
- Heating for Industrial Warehouses
- Heating for Open Spaces
Frequently Asked Questions About Greenhouse Radiant Heaters
1. What is a radiant heater and how does it work in greenhouses?
A radiant heater is a radiant heating system that transfers heat in a greenhouse through infrared waves, similar to the sun’s warmth. These waves are absorbed by the plant surface and its bed upon contact and are converted into heat. Unlike convection systems (such as heaters and jet fans) that produce hot air and cause it to accumulate under the roof, a greenhouse radiant heater delivers warmth directly to objects and surfaces. This method causes the temperature of the soil and plant surfaces to be slightly higher than the air temperature and prevents heat loss caused by hot air accumulating under the greenhouse roof.
2. What are the main advantages of using greenhouse radiant heating compared to traditional methods?
A greenhouse radiant heater has numerous advantages over traditional systems:
- Reduced Energy Consumption: At least a 50% reduction in gas consumption and a 90% reduction in electricity consumption.
- Optimal Heating of Soil and Roots: Radiant waves are delivered directly to the soil and roots, increasing their activity.
- Reduced Diseases: It prevents the formation of dew and moisture on the plant’s surface, which is the main cause of many fungal and bacterial diseases.
- No Loss of Usable Space: The devices are installed at a height, so they don’t occupy any useful space in the greenhouse.
- Temperature Uniformity: The environment’s temperature remains uniform from the soil level to the ceiling, with very little temperature difference (less than 0.5 degrees Celsius across 95% of the area).
- Fast Heating: The fire tubes heat up quickly, and the heat is felt within minutes.
- High Reliability: The presence of several separate burners in greenhouse radiant heating ensures that if one fails, the others continue to operate.
- Reduced Maintenance Costs: The system has few and visible components, making it easy to troubleshoot and repair.
- Fast Return on Investment: The cost of buying a greenhouse radiant heater is usually recovered within approximately two years through energy savings.
3. How can a radiant heater control plant temperature more precisely than hot air systems?
In greenhouse radiant heating systems, the temperature measurement device (thermostat) can receive the same radiant heat that the plants do. By placing the temperature sensor in a housing exposed to the air, it is shielded from the heat waves and only shows the air temperature, not the temperature of the objects. Additionally, with radiant heating, the air temperature can be 3 to 5 degrees Celsius lower than required in central air systems to achieve the desired temperature for the plants and soil. This feature provides more precise and optimal control over the plant’s temperature.
4. Does radiant heating have a positive effect on plant health?
Yes, a greenhouse radiant heater has many positive effects on plant health. By preventing the plant’s surface from becoming moist (which occurs in convection methods due to condensation), this system prevents the onset and spread of fungal diseases like fungal spots, downy mildew, leaf rust, and root rot. Additionally, by creating an optimal temperature in the soil and roots, this system facilitates faster plant growth and minimizes destructive temperature fluctuations, as the plant’s temperature will be higher than the surrounding air’s temperature both day and night.
5. How does a radiant heater help with productivity and maximizing greenhouse space?
The uniform heating from a greenhouse radiant heater system increases the suitable area for plant cultivation because the temperature difference between different points in the greenhouse will be very small. Even the sides and far corners of the walls that are not well-heated by traditional air heating systems are completely warmed by using greenhouse radiant heating. This allows greenhouse owners to use more effective space for growing plants and even cultivate multiple layers of plants from the floor to the ceiling at a uniform temperature.
6. What is the process for installing and maintaining a radiant heater system in a greenhouse?
The most suitable time to install a radiant heater in a greenhouse under construction is after the hall’s roof is completed. After installation, piping and wiring are done, and installing each device with the right tools takes about 4 working hours. For maintenance, it is recommended that greenhouse owners schedule annual servicing for their greenhouse radiant heating at the beginning of the cold season. This includes checking the burner and flame quality, inspecting the exhaust of combustion products, the fan’s performance, and the condition and cleanliness of the reflectors. These services are performed by the company’s technical experts to ensure the device operates correctly and optimally.
7. What factors should be considered when choosing a quality radiant heater for a greenhouse?
Choosing a safe and high-quality greenhouse radiant heater is of great importance. When selecting one, you should pay attention to the following points:
- Plant Temperature Needs: The required temperature for the cultivated plants.
- Greenhouse Dimensions and Area: Determining the necessary number and heating capacity of the radiant heaters.
- Greenhouse Covering and Structure Type: The effect of insulation, roof type, and walls on heating calculations.
- Fuel Type and Budget: Choosing a greenhouse radiant heating system compatible with available fuel and budget.
- External Environmental Conditions: Considering the coldness of the outside air.
- After-Sales Service and Warranty: Ensuring proper services and quality from the supplier.
- Proper Structural Insulation: To drastically reduce energy consumption and prevent heat loss.
8. How cost-effective is the investment in installing a greenhouse radiant heater?
The investment in installing greenhouse radiant heating is very cost-effective. In cold regions, and considering the at least 50% savings in gas consumption and 90% in electricity consumption, it can be expected that the entire cost of purchasing the devices will be recovered within approximately two years through energy savings. Additionally, benefits such as increased product quantity and quality are considered economic added value that accelerates the return on investment. A greenhouse radiant heater also requires a lower initial investment compared to engine room systems and hot water or steam piping.