How a Well-Designed Automation System Can Contribute to a More Sustainable Grow
Written By: Alex Fermon, Rico Garay, Justin Jacobs & Eric Schmidt of Argus Controls
An automated system provides full control of the processes, equipment and resources used
Environmental control systems have proven to be a key element for indoor and greenhouse growers, helping users to improve plant quality, control temperature and other variables, collect useful data and be an important labor-saving tool; however, only well-designed systems will elevate an operation to optimal efficiency levels.
What is a well-designed automation system?
A well-designed automation system is a fully integrated system. There are things that affect your grow and the yield of your crop, such as different watering techniques, fertilizer systems, lighting, venting, heating, and cooling approaches. The more of these methods you include under one platform, the better position you will be in when it comes to automation.
Implementing theses systems allows you to know how equipment is affecting different dynamics within the the grow, and you’ll have a macro and micro view of everything from what your horticultural facility is doing to what your equipment and mechanical systems in a specific zone are performing. Such a system will constantly collect data. Having this data will be key to help you drive desired results as you achieve more sustainable practices and greater efficiency. Having the data integrated with what each piece of equipment is doing is helpful. You can have pre-programmed parameters to know that everything is operating within their pre-designed setpoints and operating conditions, so you can focus on the things that are not working within that dead band. It helps you optimize so you can spend more time with the crop.
Predictive algorithms are an advantage of a high-end control system. They can consider outdoor climate conditions and anticipate what you need and where you need to be with your equipment, rather than you needing to figure it out. It allows for the environment to not have a hiccup and tries to follow setpoints as closely as possible to keep it optimized. Ultimately, you are chasing optimal environmental needs which vary from cultivar to cultivar. If you want to chase a certain vapor pressure deficit (VPD), it is going to be difficult without a good control system. Powdery mildew in your crop can be very detrimental while stressed plants are more susceptible to this and other pathogens. Therefore, if your control system does not do much – perhaps opens and closes some ridge vents but doesn’t go into deep parameters like VPD – you’ll have a harder time optimizing your operation and reaching your sustainability goals. If you have a well-designed control system, you can measure parameters like your outside temperature and what the RH is. When you start to look at psychrometrics, you can determine what kind of equipment (i.e. heaters) you would need to utilize to bring that down to both your temperature and RH setpoints. Those calculations and decisions can be automated and made for you.
Macro and micro views of your facility provided by your fully automated controls systems are key to understand processes and achieve a sustainable operation.
Argus OmniSensor in the Greenhouse.
Photo credit: Andy Colwell, Special to The Colorado Sun
One of the advantages of a fully integrated control system is having visibility of what is going on throughout the entire facility. It will give you a good view of what’s going on at your entire horticultural facility, and you can dive deeper to see a more micro view per zone. When looking at that zone view, you are looking not only at environmental parameters, but also comparing them to external parameters such as the weather station data (for greenhouses) and seeing what the equipment is actually doing. Part of an automation system – and control strategies in general – is trying to optimize how equipment and mechanical systems are utilized.
First, understand what is going on outside, then look at the equipment within a zone and try to create strategies around how to use it efficiently. In greenhouses, for example, being able to use those outdoor conditions, whether it be through solar gain or air exchange, along with having a macro view of the facility and a micro view of what the equipment is doing. This is crucial to a well-designed automation system as it allows you to see cause-and-effect.
You can make decisions within your greenhouse or growing environment related to equipment election, control strategies, and more. When you graph results, you will be able to see cause-and-effect relationships at work. Understanding this cause-and-effect at a grand scheme of things will lead to understand how you are using the resources within your facility and make the necessary changes to achieve more sustainable practices.
Another point to consider is where the water is coming from – is it fresh water, leachate, or a blend? In an indoor environment, you are often capturing condensate water. If you can reuse water, it can add to the efficiency of an automated facility, and therefore the design of a good automation system. Do not just look at why you’re watering but look at where you’re sourcing from, and why. Automating your irrigation system is also important. The decisions that go into the planning require a lot of thought – the number of feed and branch valves needed, whether you’re going onto benches, if you’ll have flood floors, decisions for watering and its timing, or are you using thresholds of VPD. With a strong automation system, you can address those decisions, chart them, see the results, and rely on data to make informed decisions in the future on how to improve the use of water.
By implementing a good automation system in place, you can add sensors and begin identifying microclimates within your zone, then make decisions such as adding equipment, heaters, half fans for better air circulation, etc. to try and homogenize the environment. If your equipment is not in place and you don’t have a good automation system, you’ll be guessing -- especially with large zones in greenhouses. Indoor grows tend to be smaller because of the real estate, but in greenhouses, growers may be making decisions on a much larger scale. Growers have made equipment changes simply because they are able to graph and document data that clearly justifies new equipment being added, exactly where and why.
How can people use the monitoring data to become more efficient and reduce costs?
Environmental Controls System Panel
The first step is to trend absolutely everything you have a sensor for, and trend it against your parameters. This means seeing the real time values of what is going on and comparing it to what you want to happen. Look at the correlations between those factors. When you have a well-designed, fully integrated automation system, you can see the direct cause and effect between what’s trending and the desired outcome you are looking for. Analyzing the data should be one of the first things you do each day when you have a fully integrated system. Look at daily, monthly, and seasonal trends. The more data, the better; it allows you to make smarter decisions around how to optimize your strategies with the equipment, and ultimately, your facility. Try to utilize equipment that costs you the least amount of money before using other pieces of equipment. That will be crucial to a well-run system and facility.
Consider running stages of cooling set up and it take into consideration the different pieces of cooling equipment available to work on a strategy, and when you want them to take effect. As you are watching or analyzing your collected data, you may find you can change some of the staging to allow for some of the less expensive equipment – such as natural ventilation – to run longer before other stages of more mechanical equipment. You can also use data to catch an event that is occurring that would otherwise go undetected until there’s an obvious failure somewhere. If you are monitoring them on a regular basis however, you are going to notice deviations that you might start paying attention to, such as a pump, fan, or other type of equipment that seems to be contributing to it going outside of its boundaries. If you did not have that data, you would probably not be able to tell until it’s having a significant impact.
Systems that have event timers tied to all the equipment in place can tell you how many times it turned on and off, and the duration. This can be quite advantageous for preventative maintenance scheduling. For example, with preventative maintenance, you want to have scheduled downtime rather than unexpected maintenance. If you have a motor running for 30,000 hours, you can set an alarm for when the motor meets certain thresholds so you know when you might need to replace it - which is much better than experiencing a breakdown, having to wait for a repair and disrupting your operation. This way you can replace it proactively, log it, then reset the event timer. With that, your preventative maintenance schedule is integrated into one system. Having the equipment working optimally, not only can save monetary resources but it is key to achieve more sustainable practices.
All these different aspects of one automation system can help create a consistent yield. For example, if you want tomatoes at a certain temperature and RH, but after some research you decide that it is a different cultivar and you want to push it and the RH a few degrees another direction, you can graph it and collect the data. Being able to measure the yields allows you to determine if you are pushing in the right direction or not.
Automation in any horticultural facility will ensure a more efficient use of resources and a more sustainable operation. With advanced algorithms, users can determine the most efficient use of resources, including using lights more efficiently, optimal use of water, heating and cooling among many other items to the extent of knowing when the equipment needs to be serviced to ensure it is working at an optimal level. Although there are many levels of automation, having a fully automated and centrally operated control system can elevate these sustainable practices to the next level.
