A lot goes into designing a good indoor agriculture environment, from selecting the right lights, to ensuring proper irrigation, optimizing airflow, and more. But while the big four – light, water, nutrients, and air – are the major keys to plant growth, the size and quality of a crop is highly dependent on a number of other factors as well. Environmental factors like humidity and temperature have a major impact on plant growth and, as a result, precision climate control has become an increasingly important part of successful indoor growing.
by Ted Tanner, Growlink CEO and Co-Founder
The importance of the perfect climate
As with all living things, plants thrive in some climates and struggle – or die – in others. The impacts of that are obvious out in nature where frigid winter temperatures or scorching desert heat render the landscape all but barren, but even in the relative comforts of an indoor grow space, small swings in temperature and humidity can have big impacts on growth, affecting both quality and yield.
Ideal growth climate
Different types of plants have different preferred climates in which to grow. Those preferred ranges aren’t necessarily static either, and while some plants will grow happily in one climate throughout their entire life cycle, others grow best in one climate during the vegetative stage and another during the flowering stage. Lettuce, for instance, grows best at around 60°F – much too cold for cannabis plants, which prefer temperatures of around 70-80°F in the vegetative stage with a bit of a cool-down when they flower.
In nature, plants get a chance to cool off when the sun goes down, and in an indoor environment, the lights-off period provides the same opportunity. The problem is that just as with day-time temperatures, plants have ideal “lights out” temperatures. The risk of cooling down too much is very real, especially in places where the outdoor nighttime temperature drop is significant. In addition to the growth problems that overly cold temperatures present, colder air also increases the risk of condensation forming on the plants – a haven for damaging molds and fungi. That makes it extremely important for growers to carefully control the temperature drop that comes along with shutting off the lights.
Most of the lights used in indoor growing give off a huge amount of heat. As a result, the risk of overheating a crop’s canopy exists even in rooms that are otherwise set to the correct ambient temperature. An overheated canopy leads to all kinds of problems, including sucking moisture out of the plants and reducing their ability to perform photosynthesis – both of which could kill a crop outright in extreme instances. Canopy overheating can be fixed by simply increasing the distance between lights and plants, or by employing LED lighting which gives off very little heat.
Heat mapping – A game-changing climate control tool
As with all indoor climate control, the first step to getting things properly dialed-in is monitoring. Traditional thermostats, while fine for setting a comfortable temperature in a home or office, have major limitations that make them generally unsuitable for serious indoor growing.
The primary drawback is that most thermostat systems only measure part of the room. Dialing in a perfect climate for a grow operation is pointless if that climate isn’t even across the entire environment. Likewise, a simple thermostat only takes into account ambient temperatures – it can’t pinpoint specific trouble areas, like a partially overheated canopy, for instance.
The solution is heat mapping. Heat mapping employs an array of thermal imaging sensors placed across an environment to accurately measure the temperature of not just the ambient air, but of all the surfaces including the canopy. The result is a clear picture of all the hot and cold areas of a room and the gradients in between them – either in the form of a color visual image or as a set of raw data points.
From a growing perspective, the benefit of heat mapping is an unparalleled level of insight into the temperature and other climate variables not just in the room as a whole, but on a plant-by-plant basis (depending on the number of sensors employed). For instance, if bad air flow in a growing environment is causing overheating in one portion of the canopy, a thermostat won’t provide that information, but a heat-map will. That kind of intelligence is invaluable when it comes to maximizing crop health.
The advanced data provided by Growlink's real-time and historical playback heat-map tool can be used to make manual adjustments or, in the case of larger operations, to control an automated climate control system that can automatically adjust room heating, lighting intensity, and humidity as necessary to keep the growing environment at an optimal setting 24-hours a day.
One of the primary goals of growing indoors is maximizing control over the many factors that go into producing the best crop possible. Of those factors, the climate is both one of the most important and the most controllable. However, it’s impossible to tightly control something that can’t be accurately measured, and measurement has long been the weak point in climate control. Thanks to high density sensors and visual heat mapping, indoor growers can now access a real-time picture of the exact profile of their growing environment, allowing them to fine-tune their systems to a level never before possible. The result is perfectly tuned growing environments that boost productivity by increasing yields, reducing losses and cutting down input costs.