Hot, dry climates (Arizona, Nevada, Southern California)
In these climates, we absolutely recommend indoor, sealed cultivation. While greenhouses are a great way to save energy on lighting, using the sun as your primary source of light means astronomically high solar gains– and thus, heat. Add on to that the incredible temperatures these regions experience most of the year and it is simply not economical to use sealed cooling in your greenhouse. Instead, growers end up having the vent the greenhouse with outside air at least some of the time, which can be counterproductive for most of the year due to high temps. In order to ensure a controlled, cool environment in these regions, we really recommend indoor or hybrid facilities (Check out our new hybrid facility design which gives you all the control of an indoor grow while using 60% less energy!!)
The other big issue is determining how much tonnage is needed. If you don’t already know, cooling systems are quoted by tonnage; however, what a lot of people overlook is that the tonnage quoted is done so at a specific temperature parameter– usually around 80F. However, when temperatures rise into the high 90s and even the 100s, chillers (regardless of the brand) are de-rated and begin functioning at a lower tonnage. For example, any 100 Ton chiller in Phoenix in July really becomes a 85T chiller. So, it is important to consider the de-rating of your equipment and be sure you get enough tonnage to cover your needs on the hottest day of the year.
Humid climates (Western Washington and Oregon, Northern California, Northeastern United States)
Humid climates present a similar issue for greenhouses as those in hot climates. Again, because of solar gains, it is usually not economical to seal and cool greenhouses completely and so growers resort to bringing in outside air. Because the climate is so humid already, this venting makes it virtually impossible to control humidity levels and creates a perfect environment for mold and fungus to grow. Bringing in outside air also means bringing in any bacteria or mold spores that are around the area, putting your crops at further risk. For that reason, we again recommend indoor or hybrid facilities.
Whichever way you choose to cultivate, the major consideration here will be your level of dehumidification. Often, growers underestimate how much dehumidification they need. The rule of thumb is that you should be removing the same amount of water that you put in. All dehumidifiers are rated based on how many pints per day they can remove but, like chillers, they are rated at a specific level (around 80F and 60%RH) and de-rate when they drop below that point. Because humidity is a constant moving target, we recommend you ask an expert to help you determine exactly what you need.
Cold Climates (Alaska, Colorado, Canada, Michigan, Northeastern United States)
There are some benefits to cultivating in colder climates. For one, Surna chillers work pretty efficiently in colder climates. Second, you have the option of adding a dry cooler into your cooling system. A dry, or free, cooler is a compressor-less chiller that uses ambient conditions to cool the water inside. The compressor on a chiller has the greatest power draw and so bypassing it with a dry cooler can reduce energy consumption by up to 75%! So adding one of these is a no-brainer.
In colder climates, it’s really most important that you use a cooling system that is designed for cold weather. Most of the traditional HVAC options out there are designed to cool your home, office, etc. when it’s hot outside and, thus, don’t work as well (and malfunction more often) in colder climates. A Surna hydronic cooling system is designed to cool warm rooms even when ambient conditions are below freezing. But, whichever way you decide to go, you should, at the very least, be sure that any chiller you use has a low ambient kit to keep it from freezing in low temperatures.
Surna has been designing equipment for indoor cannabis cultivation longer than any other climate control company out there. We’ve designed projects in almost every legal state and we’ve experienced first hand the unique challenges that each region presents. Get in touch with us today so we can help you design the right system for your location!