If greenhouses are going to produce the majority of the world’s food in the future, they must be efficient.
Greenhouse facilities can help the agricultural industry accelerate innovative, sustainable and technically advanced solutions. Through the controlled environment of a greenhouse, growers can mitigate impacts to crops from adverse weather and prevent delays in new seed development. What’s key, however, is to have control over this controlled environment.
There are many systems at play with greenhouse facilities that need to be properly tested upon commissioning so that major issues don’t crop up. If any system impacting the temperature of the greenhouse were to fail — even for just two hours — it could result in significant losses. A greenhouse can build up a massive amount of heat in a short time. This temperature directly impacts whether the seed can progress to the next stage of development and how efficiently the plants grow.
Greenhouse facilities should seek to maximize the amount of air movement through the space to cycle out the hot air that comes from the facility’s lighting and the thermal gain from the sun shining into the greenhouse. While complex, there are various strategies to maintain the temperature while maximizing energy savings without causing too much discomfort within the greenhouse. Facilities are usually designed with a tiered approach that offers flexible variation depending on outdoor conditions. For example, one tier may be to open ridge vents and get a natural stack effect to drive natural ventilation. If further cooling is needed on a hot day, the facility could then employ another tier that involves a mechanical method to achieve the necessary cooling.
Commissioning provides intentional steps to minimize risk and check that the greenhouse’s programs and systems are designed and installed correctly. It’s a process for verifying that you get what you pay for. Commissioning processes allow a facility owner to document that systems work, materials are as expected, and that overall project performance meets defined objectives and criteria.
Throughout the early stages of a greenhouse project, a commissioning team reviews the design and construction plans so that the project is set up for successful commissioning. A commissioning team works closely with the greenhouse facility controls contractor, who will be responsible for the daily management of the facility.
Once the greenhouse is constructed, the commissioning team conducts an on-site visit. After the initial walk-through, preliminary testing is completed. This often includes an array of temporary sensors placed throughout the greenhouse, spread evenly apart horizontally and vertically, to essentially make a 3D grid of the temperature in the greenhouse. These sensors — which can be installed for weeks or months to mirror a growing season — identify any hot spots or sections in the greenhouse that are not getting proper air movement. This 3D grid is critical because as crops, such as corn, progress through the growing process, the temperatures across the entire house need to be maintained. With this data, the commissioning team can recommend any necessary system changes.
Commissioning teams also look into the resiliency of greenhouse facility systems to identify key challenges and solutions for owners. For example, a greenhouse facility needs to have a plan for when the power goes out or when water is unavailable for periods of time. Commissioning efforts can provide full disclosure so that owners have the insight to inform their response plans.
Whether caused by a power outage or a program failure, crop devastation in a greenhouse can become a reality within hours. If a commissioning team can identify issues that may result in the loss of future product, commissioning efforts pay for themselves. This step also offers peace of mind that professionals are on-site with the technical and mechanical background to collaborate with contractors and see that the key aspects of a facility’s functionality are aligned — with the highest in importance — with the facility owner.
The participation of commissioning professionals throughout the life of a project as a strong owner-advocate contributes to the project’s success.