Irrigation systems in Vertical Farms

Unlike traditional agriculture, vertical or indoor farming uses soil-less cultivation techniques that all rely on high-precision, streamlined irrigation solutions. Whether circulating water, dosing nutrients, or controlling and balancing water flow and pressure, irrigation solutions are critical to creating an optimal indoor farming climate and favorable plant growth conditions.

Different types of irrigation methods

When you’re setting up your indoor farm, there are different types of irrigation methods, depending on how you choose to cultivate your crops, where you place your vertical farm, and which crops you choose to plant. Some of the more common methods are:

• Hydroponics, where roots are submerged into a nutrient-rich water solution.
• Aeroponics, a system that mists the root system directly with nutrients.
• Aquaponics, a system that combines raising fish with plant cultivation, utilizing fish waste to nourish plants.

Whichever method you choose, one thing is certain. You will need a system that can consistently deliver water and nutrients to your crops. One that can distribute water and/or nutrients precisely, so that nothing is wasted. This is where water and energy efficiency enter the picture.

Why you need to optimize your irrigation system

1. To use water efficiently. Distributing water evenly across the entire growing area is essential for preventing uneven crop growth and yield variability. You need to calibrate and maintain your irrigation system regularly to achieve an optimal system design with consistent pressure levels.
2. To use energy efficiently. Most irrigation systems need energy to operate pumps, valves, and other components. By minimizing energy usage and increasing efficiency, you can reduce energy-related operating costs and your indoor farm’s environmental impact.

In the next section, we’ll explore different techniques you can use and points you should consider when designing the optimal irrigation system for your indoor farm project.

Hydroponics is a method of growing plants in a soilless medium while providing all the necessary nutrients directly to the plant roots.

The correct nutrient balance is maintained by dissolving the necessary nutrients in the water that circulates directly around the plant’s roots.

What are the most common types of hydroponic systems? 

Some common types of hydroponic systems include:

• Ebb and flow system. In an ebb and flow system, also known as flood and drain systems, growers flood a grow bed with a nutrient solution and drain it again using a submersible pump. 
• Nutrient film technique. The nutrient film technique uses the combination of submersible pumps, a growing bed and a reservoir to coat plants' root systems with a nutrient film. 
• Drip system. Drip systems are a type of hydroponic system where nutrient solutions are distributed to plants through drip lines. 

What are the advantages of a hydroponic system?

Hydroponic methods consume up to 90% less water than traditional field crop watering methods because most systems use recirculation techniques to maximize water conservation. 

Variable Speed Drives (VSD)

In hydroponic systems, various types of pumps are used to circulate water and for dosing the nutrients to the plants' roots. The pump you choose will depend on factors such as system size, flow rate requirements, pressure needs and the specific hydroponic system.

Many growers choose to use Danfoss Variable Speed Drives (VSDs) with the pumps in their hydroponic irrigation systems. By combining VSDs with the pumps in your hydroponics system, you get:

• Increased energy efficiency
  VSDs allow you to adjust the pump motor’s speed based on the actual water demand. Instead of running the pump at full speed constantly, which can waste energy, VSDs can adjust the speed to match the required flow rate. This can lead to significant energy savings compared to fixed-speed pumps.

• More precise control
  VSDs provide precise control over the pump’s flow rate to easily adjust for specific requirements.
• Reduced wear and tear
  Running a pump at full speed constantly can lead to increased wear and tear on the pump motor and components. By using a VSD to adjust the speed based on demand, the pump operates more efficiently and experiences less mechanical stress, potentially extending its lifespan.
• Condition-based monitoring to optimize uptime in your pumping applications.
• Noise Reduction
  Pumps operating at lower speeds generate less noise compared to those running at full speed. This can be advantageous in indoor hydroponic systems where noise levels need to be kept to a minimum.
• Improved pressure control
  VSDs can also help maintain consistent pressure levels within the irrigation system. This is important so you can make sure you can uniformly distribute the nutrient solution to your plants.

Solenoid valves

In hydroponic irrigation systems, solenoid valves are commonly used to control the flow of water or nutrient solution to different sections of the system. There are various types of solenoid valves available, but the most common types in hydroponics are normally closed, normally open and direct acting solenoid valves.

How can I choose the right solenoid valves for my irrigation system?

When selecting solenoid valves for a hydroponic irrigation system, consider factors such as:

• flow rate,
• pressure rating,
• material compatibility
• voltage requirements

This will help you ensure that your system functions properly and extend its lifetime. Additionally, it's essential that you choose solenoid valves specifically designed for use with water or nutrient rich solutions to prevent corrosion and contamination issues.

Pressure Independent Balancing and Control Valves (PICVs and PIBCVs)

For commercial growers or more complex vertical farm systems, precise water management is critical for optimal plant growth. For these farm types, installing the Danfoss Pressure Independent Control Valves (PICVs) or Pressure Independent Balancing and Control Valves (PIBCVs) can provide you with greater control, efficiency and reliability.

What should I consider when selecting PICVs or PIBCVs?

When selecting PICVs or PIBCVs for a hydroponic irrigation system, consider material compatibility. This will help ensure your system functions optimally, extend its lifetime and prevent corrosion and contamination issues.

The benefits of using PICVs and PIBCVs are:

• Pressure Regulation
  PICVs maintain a constant flow rate through the valve regardless of fluctuations in system pressure. This ensures water is delivered consistently to the plants, even if there are variations in pressure due to changes in demand or other factors.
• Balancing
  In systems with multiple branches or zones, PICVs can help balance the flow of water to ensure equal distribution among different sections of the system. This is important for maintaining uniform growing conditions across the entire crop area.
• Energy Efficiency
  By stabilizing flow rates and reducing pressure differentials, PICVs can help optimize energy consumption by pumps and other components in your irrigation system.
• Control
  PICVs often include control features such as temperature or flow control actuators, allowing for precise adjustment of flow rates based on specific requirements. This level of control is beneficial in hydroponic systems where different plants or growth stages may have varying water needs.
• Maintenance
  PICVs can simplify system maintenance by reducing the need for frequent adjustments or manual balancing of flow rates. Once set up properly, they can operate autonomously within specified parameters.

In aeroponic systems, specialized nozzles deliver a nutrient rich solution as a fine mist directly to the plants’ root systems. These nozzles must produce droplets of a specific size to ensure optimal nutrient absorption and minimize waste.

What do I need to consider when designing an aeroponics system?

When selecting nozzles for an aeroponic system, consider factors such as:

• droplet size, flow rate, and spray angle
• operating pressure and material durability
• high-quality dimensional repeatability to keep a solid and stabile system operation

This will help you ensure your system’s optimal performance and longevity and create the right aeroponic environment for food production.

While many aeroponic nozzles operate efficiently at lower pressures, some aeroponic system components, such as micro-sprinkler nozzles, may require higher pressures.

TIP: It's essential to select the appropriate pump and nozzle combination based on your aeroponic system’s specific requirements to ensure optimal performance and efficient water and nutrients delivery to the plants. We are more than happy to find the right customizable solution for your needs, backed by the solid support of Danfoss engineering.

We’re here to help you find the best solution for your aeroponics system.

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