Today we discuss popular cannabis greenhouse models offered at Atlas Greenhouse – Totally Enclosed and Hybrid!
What is a Totally Enclosed Greenhouse?
Totally Enclosed Greenhouses are 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.
What is a Hybrid Greenhouse?
Hybrid Greenhouses utilize the design concept of a Positive Pressure Greenhouse but adds one additional and very useful item- Air conditioning!
Hybrid greenhouses can utilize dehumidifiers, chillers, coolers, or traditional HVAC. This allows the grower to use the greenhouse as a traditional greenhouse most months of the year, utilizing outside air. During those months when the air is too hot, or more likely, too humid, the outside vents close and instead of pulling outside air into the greenhouse, chillers or air conditioners scrub the air free of humidity, mold, pollen, spores and of course lower the temperature. This cold air is then pumped into the cooling chamber where it is pulled into the greenhouse and distributed through the ducts under the crop’s root structure and is forced through the canopy. During this period, the greenhouse remains closed, and the air is returned back to the cooling chamber to be scrubbed of humidity, and heat and then pumped back into the greenhouse.
While this offers incredible control and the most ideal environment, the utility expense during this period can be 10 times or more expensive than the traditional positive pressure method of cooling a greenhouse through evaporation of outside ambient air temperature. Many growers will argue that this is the best option available today giving them the ability to utilize many different environmental control options as the seasons change to make their operation as efficient as possible.