The most controlled environmental option available on the greenhouse market at this time. A totally enclosed greenhouse utilizes the design of positive pressure along with traditional HVAC heating and cooling to consistently set the temperature and humidity to the exact set points desired and the ability to achieve those set points year-round regardless of outside temps or humidity. The capital expense of this option, as well as the ongoing energy use make this the highest price option; however, it is the most accurate control. In this option, growers have the result of an indoor growing facility with complete control of temperature and humidity, but one key factor that makes this option attractive in today's cannabis market- Natural sunlight! That sunlight, however, has played a major role in limiting the success of year-round cultivation of high-quality flower in other greenhouse ventilation and cooling options previously discussed. As the sunlight rises above the horizon it immediately begins creating a solar buildup in the greenhouse.
The thermal load from the sun, especially when humidity levels are very high, is less than ideal for cannabis in flower making it at times almost impossible to maintain acceptable plant health during this period and can lead to crop failure and loss. DLI (Day Light Integral) is a measure of the total light accumulated in a 24-hour period. When growing in a greenhouse, growers can reach a DLI of 40 moles per day per meter squared, which is an ideal light accumulation and is unobtainable in an indoor growing environment with only grow lights. There truly is no substitute for the sun when growing plants, but a totally enclosed greenhouse provides growers with a clean, exact condition while still letting the sun in.