Tag Archives: infrastructure

Why the Central Chiller Isn’t So Central to Grow Room HVAC

By Geoff Brown
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There’s a better way to design HVAC for cannabis grow rooms, and it may seem a little odd at first.

Central chillers are a tried-and-true solution for projects requiring large refrigeration capacity. They’re found in college campuses, hospitals, office buildings and other big facilities.

While central chillers are a good default for most large-scale applications, they fall short in this industry. Grow rooms, with their need for tight, variable conditions and scalable, redundant infrastructure, have HVAC requirements that the central chiller model simply can’t deliver on.

Let’s unpack the shortcomings with the central chiller in this niche and explore some possible solutions.

What’s Wrong With Chillers?

Building a scalable HVAC system is essential for the cannabis industry as it continues to ramp up production in the U.S. and Canada.

Many growers are building their large facilities in phases. In Canada, this is common because growers must have two harvests before they can receive a production permit, so they build just one phase to satisfy this requirement and then build out the facility after the government’s approval.

This strategy of building out is less feasible with a central chiller.

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Indoor cultivator facilities use high powered lights that give off heat, requiring an efficient air cooling system.

A chiller and its supporting infrastructure are impractical to expand, which means it and the rest of the facility needs to be built to full size for day one, even though the facility will be in partial occupancy for a long time. This results in high upfront capital costs.

If the facility needs to expand later down the road, to meet market demand for example, that will be difficult because, as mentioned, it’s expensive to add capacity to a central chiller.

Additionally, the chiller creates a central point of failure for the facility. When it goes down, crops in every room are at risk of potentially devastating loss. Grow rooms are unusual because of their requirement for strict conditions and even a slight change could have big impact on the crop. Losing control due to mechanical failure could spell disaster.

One Southern Ontario cannabis grower met with some of these issues after constructing their facility, which uses a central chiller for cooling and dehumidification. The chiller was built for full size, but the results were disappointing as early as phase one of cultivation. While sensible demands in the space are being easily met, humidity levels are out of control – flowering rooms are up to 75% RH.

Humidity is one of the most important control aspects to growers. Without a handle on it, growers risk losing their entire crop either because there’s not enough and the plants dry out, or there’s too much and the plants get mold disease. This facility has fortunately not yet reported serious crop issues but is mindful of the potential impact on harvest quality.

By going unitary, capital costs scale on a linear basis.If tight control over humidity is what you need, then a chilled water system needs very careful consideration. That’s because typical chiller system designs get the coils cold enough to lower the air temperature, but not cold enough to condense water out of the air as effectively as a properly designed dehumidifier coil.

A chilled water system capable of achieving the coil temperatures needed for adequate dehumidification in a typical flower room will also require full-time reheat to ensure that air delivered to the plants isn’t shockingly cold — either stunting their growth or killing them altogether. This reheat source adds complexity, cost and inefficiency which does not serve growers well, many of whom are under pressure from both utilities and their management to minimize their energy usage.

How Do Unitary Systems Solve These Problems?

Compared to central chillers, a unitary setup is more agile.

A facility can commence with the minimum capacity it needs for start-up and then add more units in the future as required. They’re usually cheaper to install than a central system and offer several reliability and efficiency benefits as well.

The real business advantage to this approach is to open up the grower’s cash flow by spreading out their costs over time, rather than a large, immediate cost to construct the entire facility and chiller for day one. By going unitary, capital costs scale on a linear basis.

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One of the flowering rooms in an indoor set up (Image: Tall Trees LED Company)

Growers can have more control over their crop by installing multiple units to provide varying conditions, room-by-room, instead of a single system that can only provide one condition.

For example, flowering rooms that each have different strains of crop may require different conditions – so they can be served by their own unit to provide variability. Or, rooms that need uniform conditions could just be served by one common unit. The flexibility that growers can enjoy with this approach is nearly unlimited.

Some growers have opted for multiple units installed for the same room, which maximizes redundancy in case one unit fails.

A cannabis facility in the Montreal area went this direction when building their HVAC system. Rather than build everything in one shot, this facility selected a unitary design that had flowering rooms served independently by a series of units, while vegetation rooms shared one. The units were sized to provide more capacity than currently required in each room, which allows the grower to add more plants and lighting in the future if they choose.

This facility expects to build more grow rooms in a future phase, so it was important to have an intelligent system that could accommodate that by being easy to add capacity to. This is accomplished by simply adding more units.Multiple, small systems also have a better return-on-investment.

The grower, after making a significant investment in this facility, was also averse to the risk of losing crop due to mechanical failure, which is why they were happy to go with a system of independent grow room control.

Multiple, small systems also have a better return-on-investment. Not only are they easier to maintain (parts are easier to switch out and downtime for maintenance is minimal) but they can actually be more efficient than a large, central system.

Some units include heat recovery, which recycles the heat created by the dehumidification process to efficiently reheat the unit’s cold discharge air and keep the space temperature consistent, without needing expensive supplementary heaters. There’s also economizer cooling, which can be used to reduce or even eliminate compressor usage during winter by running the unit on dry outside air only.

Demand for cannabis continues to increase and many growers are looking to expand their businesses by adding new facilities or augmenting existing ones. Faced with the limitations of the traditional chiller system, like the lack of flexibility, scalability and redundancy, they’re looking for an intelligent alternative and the unitary approach is earning their trust. It’s expected this option will soon become the leading one across North America.

Seven Steps To Avoid the Green Rush Blues: Investigate Water Supplies Before Planting Cannabis

By Amy M. Steinfeld
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A clean, reliable water supply lies at the heart of every successful cannabis farm. It’s no surprise that the stakes for finding land with ideal growing conditions, including adequate water, are high. But new buyers (and lessees) caught up in the green rush often gloss over water rights or are unaware of California’s byzantine rules governing the irrigation of cannabis.

Water rights are complex. Water regulations applicable to cannabis cultivation are even more complex. And our new climate reality convolutes things further. Longer droughts, more volatile weather, political uncertainties, increased groundwater regulation and water quality concerns are exacerbating tensions over local and statewide water supplies. In many areas of California, landowners can no longer rely on local water districts to meet their needs.

A robust investigation of the property must consider water supplies. Because a property’s water supply is dependent on water rights, local ordinances, state regulations, politics and hydrology, it’s important to consult a water lawyer (and in some instances a hydrologist) before closing. A bit of foresight can prevent a grower from being left high and dry.

The following checklist provides a roadmap to conduct water rights’ due diligence. While many of these details are California-specific, this type of due diligence applies throughout the West.

Step 1: Identify Available Water Supplies and Consider Potential Limitations On Irrigation, Including Potential Future Changes

Conduct a site visit to identify existing water infrastructure, natural water features and existing or potential water service options. Next, determine if the property is served by a public water supplier. If that’s the case, the California State Water Resources Control Board (“State Water Board”) does not require any specific documentation to irrigate cannabis, but the water supply must be disclosed in the CalCannabis license application.

Groundwater is generally the best supply for cannabis, but the era of unregulated groundwater pumping is over. Many groundwater basins in California are now governed by the Sustainable Groundwater Management Act (“SGMA”), which requires water agencies to halt overdraft and restore balanced levels of groundwater pumping from certain basins. As a result, SGMA may result in future pumping cutbacks or pumping assessments. It’s imperative to identify the local groundwater basin via the Department of Water Resources’ Bulletin 118, and determine whether the groundwater basin is adjudicated or governed by a groundwater sustainability agency. Growers should also test the local water supply’s pH and salt levels because cannabis plants are finicky and water treatment can be cost prohibitive. If a new well is needed, growers should consult with their local county before drilling a new well. In some areas, moratoriums and restrictions on drilling new wells are on the rise.

As a rule of thumb, cannabis cultivators should avoid using surface water to irrigate cannabis. Surface diversions are subject to the California Department of Fish and Wildlife’s permitting authority. And under the interim State Water Board Cannabis Policy, commercial cannabis cultivators cannot divert anysurface water during the dry season (April 1 through Oct. 31), even if they have a riparian right that can be used to irrigate other crops. During the dry season, cultivators may only irrigate using water that has been stored off-stream. And even during the wet season, cannabis cultivators must comply with instream flow requirements and check in with the state daily to ensure adequate water supplies are available. Cannabis cultivators are also required to install measuring devices and track surface water diversions daily. And buyer beware, a groundwater well that extracts water from a subterranean stream may be considered a surface-water diversion. So be especially cautious if the well is located close to a creek or river.Develop a water use plan to optimize water efficiency 

Step 2: Identify Water Supplies Used On the Property, Including the Basis of Right, and Quantify Historical Use

Review information on historic and existing water use. This may include past water bills and assessments. If there is a well on the property, the seller or lessor may have metering data, electrical records and crop data that can establish historic groundwater use. Cultivators must submit a well log to CalCannabis as part of the cannabis cultivation application. If surface water is available, the purchaser should review the State Water Board eWRIMs database for water rights permits, licenses, stock pond registrations and certificates, decisions and orders. The purchaser should also identify surface water diversion structures and review annual filings to determine compliance with all terms and conditions of the water right. Lastly, the purchaser should request all documents and contracts pertaining to water rights.

Realistically estimate water demand for irrigation and other on-site purposes.Step 3: Confirm Ownership of Right and Assess Any Limitations On Water Right

Determine whether the right has been abandoned, lost to prescription or forfeited. Evaluate the seniority of the water right, availability of the right, adequacy of place of use, purpose of use (must include irrigation), season of use, and quantity of any permitted or licensed post-1914 right. Determine whether historical diversions pursuant to an appropriative right support the full amount of the claimed right, and whether any changes to the water right are needed to support the proposed new use. Cultivators in California who plan to utilize surface water also need to file for a “Cannabis Small Irrigation Use Registration” to store water during the wet season for use during the dry season.

Step 4: Reconcile Water Demand With Available Supply

Realistically estimate water demand for irrigation and other on-site purposes. Develop a water use plan to optimize water efficiency (drip irrigation, rainwater harvesting, water monitoring, hoop structures) regardless of supply sufficiency. Many counties, such as Santa Barbara County, require that cannabis growers meet certain irrigation efficiency standards. Determine whether available supplies can meet all proposed demands, including plans for full buildout. If not, consider whether additional supplies are available for use on the property.

Step 5: Determine Water Supply Compliance Obligations

 The rights associated with water supplies are defined by their source, the time frame during which supplies can be taken, the quantity of water to which the right attaches, and any limitations on the purpose of use of the water supply. There may also be reporting requirements associated with taking and using the supply—these can include requirements to report the quantity of water used as well as information regarding the end use of the water. Failure to timely report can have serious consequences. Cannabis cultivators are also subject to additional water quality regulations and restrictions, including waste discharge requirements pursuant to the State Water Board’s Cannabis General Order.

Step 6: Negotiate Deal and Draft Conveyance Documents

After obtaining an understanding of the water supply associated with the property, the property conveyance documents may be drafted to incorporate the transfer of rights associated with the property’s water supplies. These may include the assignment of contracts pursuant to which water supplies are obtained, the transfer of permits or licenses as to the water supplies, or the transfer of water rights arising out of a judgment or decree.

Step 7: Consider Unused Water Supply Assets That Could Be Monetized 

To the extent the water supply rights associated with the property exceed the cannabis plants’ water demand, it may be possible to monetize unused or excess water supply assets through transfer of the rights to a third party.

If you have any questions about water rights related to cannabis cultivation it’s always in your best interest to contact an experienced water attorney early on in the process.

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CannaGrow Expo Heads to Palm Springs

By Aaron G. Biros
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canna grow

We’ve covered the CannaGrow Expo previously, but this time around we catch up with Joseph De Palma, founder of CannaGrow, to talk about the genesis of his conference and what makes the event so special. This year’s CannaGrow Expo heads to Palm Springs, California, a new location for the event, on May 19thand 20th.

We’ve watched De Palma’s conference grow over the years, moving around the country and becoming the tight-knit community we know it as today. The meat and potatoes of the show are definitely the educational sessions, panel discussions, roundtables and the expo hall. But covering it year after year we’ve noticed a real sense of community develop, one where genuine idea sharing, collaboration and inclusivity are preached. There are no dumb questions at the CannaGrow Expo.

Tom Lauerman speaks to a room full of attendees at CannaGrow San Diego

According to Joseph De Palma, CannaGrow started in 2014, when the original event was held in Denver. “From the beginning, we wanted to create an event specifically for growers, where the focus was always on education and ‘becoming a better grower’,” says De Palma. “We had experienced the existing events in the marketplace, and almost all fit into two categories at the time, festival, or generic tradeshow. Those were fine for their purpose, but they didn’t foster an environment of education, and that’s what we believed was most important to the emerging cannabis industry.” Back in 2014, their show only had 10 sessions and 30 exhibitors. “Passionate growers from around the country had 2 days of grow-focused sharing and learning, and you could see the energy and excitement,” De Palma says. “Discussions would dive deep, people made new friends, and it really elevated the conversation around cultivation.”

Attendees gather at a lighting exhibit at CannaGrow San Diego

Since the show’s debut, it’s grown substantially. The 7th CannaGrow Expo is fast approaching, and this upcoming conference has four separate tracks and roughly 100 exhibitors. But it still keeps its sense of community, one where you don’t feel crowded, where everyone has time to chat and network, without the overwhelming feeling that can come with larger trade shows. “That inclusivity and open dialog is built in,” says De Palma. “If you go to an event that’s tradeshow dominant, most people are there to walk, shop, and leave. At CannaGrow, growers and extractors come together with a plan for the weekend, remaining in a constant state of engagement with others at the show.”

This year’s show has some exciting additions to look out for. The agenda covers a wide range of topics, including everything from an introduction to growing with living soil to a discussion of cyber security. The Extraction Summit, new to this year’s event and held on Day 2, is their response to the massive rise in popularity and demand of extracts.

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Eric Schlissel, president and chief executive officer of GeekTek

Eric Schlissel, cybersecurity specialist, president and chief executive officer of GeekTek, is giving a talk focused on IT infrastructure. “My presentation will center around the actions cannabis businesses need to take right now to repel cybercrime and potential federal seizure,” says Schlissel. “As cannabis operators build their businesses and develop their security strategies, they often focus exclusively on the physical portion of their business – the merchandise and the cash in particular – and overlook the importance of designing and fortifying a secure IT infrastructure. I will discuss the importance of a holistic security strategy that embraces both and how you can both create one and prepare it for expansion into other states or even globally from the very start.” Schlissel’s discussion is one example of just how all-encompassing CannaGrow intends to be.

De Palma and his team leave few stones unturned as the show truly delivers vital information for cannabis cultivators in every area. Some things we are looking forward to? Seeing old friends and learning everything under the sun about cannabis science, growing and extraction. “People get to know each other, and with everyone sharing a core passion for cultivation and extraction, lifelong friendships are made,” says De Palma.


To check out the agenda, speakers and exhibitors, click here.