An effective greenhouse is the engine of your business. Without the proper environment, you can encounter many issues that harm your crop. Investing in greenhouse environmental control systems can simplify or automate many essential aspects of growing, from nutrient supplementation to temperature management.
But what should you consider before choosing an environmental control system?
Every greenhouse is unique, and every space in it serves a specific purpose. Depending on your crop, climate, and equipment layout your needs as a grower will vary significantly from the next. Still, every cultivator should assess several factors to determine which control systems suit their business, including budget, crop value, and desired complexity of features.
It is very important to understand that an improved or updated control system is only as good as the equipment it is controlling.
Types of Environmental Control Systems
Greenhouse environmental controls come in several general categories based on purpose, cost, and features. Depending on the scale or layout of your greenhouse, you may need more or less automation.
All environment control systems operate by sensor(s) that enable, disable, or modulate greenhouse equipment in sequences to create the growing environment.
To deliver optimal levels of light, temperature, airflow, water, and nutrients to your crop, environmental control systems will operate your equipment in strategic sequences. This corresponds with setpoints decided by the grower, typically influenced by the season.
Automated greenhouse controls let growers create the desired environment without constant management of equipment sequencing. However, no system is ‘set-and-forget,’ and all will require regular observation to ensure the system is performing as intended, particularly with seasonal changes.
The broad categories of greenhouse environmental controllers can be broken into a few groups like listed here. Depending on the unique factors of your greenhouse as discussed above, one category may be a more sensible choice than others when choosing a controller.
- Thermostat, Humidistat, or Timer Controls: The simplest type of controller, this will turn equipment on or off based on single set points or time periods. This type of controller does not integrate several types of equipment but controls them separately. An example is a thermostat that enables a heater when a setpoint is reached or a timer that enables lights to turn off at a specific time.
- Step Controls: These controllers allow for multiple set points that can stage equipment to come on in groups. This allows for different control strategies to be used for different weather conditions. An advantage that this type of controller has over simple non-integrated thermostats and timers is efficiency and accuracy, particularly in the shoulder months. For example, a step before enabling exhaust fans in a greenhouse can be opening vents and allowing passive exhaust of hot air.
- Single-Zone Controllers: These controllers can be a cost-effective and simple form of step controllers if operating a 1-2 zone greenhouse. Modern single-zone controllers can sometimes have advanced features like data logging, push notifications, or cloud-based interfaces.
- Advanced Integrated Controllers: These are the most complex digital controllers and can be customized to any combination of equipment, or facility size. They can stage equipment in multiple setpoints, but also create custom programming and dependencies. This allows for the most advanced levels of integration of the different parts of the greenhouse system. This level of technology is the most expensive type of greenhouse controller with regard to cap-ex investment, but more efficient and intelligent control strategies can translate to op-ex savings.
How to Choose Environmental Control Systems for Your Greenhouse
There can seem to be innumerable environmental controls on the market, but by narrowing it down to a category type you can simplify the selection process. It can take time to evaluate your needs relative to your greenhouse system but is worthwhile for an investment of this nature.
Consider the sophistication of your greenhouse equipment. Are there pain points with regard to creating the type of environment you need? How tight of tolerances to setpoint does your crop require? Do you wish to evaluate the data from the previous years to develop a path of continuous improvement?
Either way, start from the ground up by examining your production needs, finances, and equipment setup.
1. Determining the Needs of Your Greenhouse
Consider your current operation, but also plan for future expansions. The sophistication and amount of environmental control equipment of your greenhouse play a critical role in determining how much automation you need.
Assess your overall layout and different crop requirements. How many different zones with discrete settings do you wish to have? How many plants do you typically grow in a season? Does your current equipment layout allow for the desired type of control, or must you update the equipment to be controlled as well?
2. Consider Your Crop Value and Yields
Do you anticipate better yields by tighter environmental control? If so, then the environmental control system investment may pay back quickly. The limiting factor in your growing system may not be in the equipment sequencing but in the need for supplemental lighting. This may impact the priority you put on updating or renovating controls.
Alternatively, implementing more complex environmental controls for all aspects of cultivation operations (e.g., nutrient supplementation, humidity management, airflow, etc.) may be ideal for greenhouses with multiple hundreds or thousands of plants.
3. Ensure your Heating and Cooling Equipment is Sized Properly
If your fans are not properly sized to exchange the air in the greenhouse as the temperature increases with the solar gain, a new environmental control system will not create a cooler environment. Evaluate your structure and the equipment capacity before assuming that a controller will solve environmental problems.
4. Identify Potential Risks and Pain Points to Your Operation
A control system can monitor critical parameters and send alarms in the event of adverse conditions or equipment failures. The cost to add these features may far outweigh the outcomes of an unnoticed or unchecked equipment failure in the greenhouse.
A weather station add-on to your control system can offer added protection to roof vents by modulating them based on wind speed.
Using this information, you can determine which systems are necessary for your business and which are add-ons (if budget allows).
5. Conduct a Cost-Benefit Analysis Regarding Sophistication
Budget is a major barrier for many greenhouse growers. While you may want to pursue automation in every cultivation area, your revenue may not allow such growth. Time studies can help with focusing on what aspects of cultivation will benefit most from added automation.
Start by listing your desired options with a detailed description of their benefits, drawbacks, features, and costs. Use this sheet to compare each system. Which implementation will save you the most time and money in the long term? Does one require less construction or maintenance?
In the end, you should have a general idea of the best type of option for your operation.
6. Explore the Environmental Impact
With advancing climate change concerns, eco-friendly environmental control systems are a must for many agriculturists. Superficially, automation appears more efficient and energy-saving than traditional cultivation methods. For example, they reduce waste through controlled water allotment and timed lighting schedules.
Irrigation timed to be delivered automatically at a slow rate, directly to the plant media is far more efficient and less wasteful than hand-watering the same crop. This is true for labor and water usage.
For additional information and details on environmental control choices and options, please read the original article from LLK Greenhouse Solutions.
