Tag Archives: flowering

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.

solsticegrowop_feb
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.

Talltrees
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.

Image 2: Temperature display provides quick view of sensor data

10 Questions To Ask Before Installing a Remote Monitoring System

By Rob Fusco
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Image 2: Temperature display provides quick view of sensor data

No matter the size of your cannabis greenhouse operation, keeping your plants alive and healthy requires the best possible growing environment. This means greenhouse managers and personnel must frequently monitor the status of environmental conditions and equipment. The sooner someone discovers extreme temperature fluctuations, rising humidity or equipment failure, the more inventory you can save.

Image 1: Cloud-based remote monitoring system in protective enclosure
Cloud-based remote monitoring system in protective enclosure

That’s why integrating a remote monitoring system into your greenhouse operation can save you time, money and anxiety. Monitoring systems that use cloud-based technology let you see real-time status of all monitored conditions and receive alerts right on your mobile device.

Installing a monitoring system and sensors can be easier than you might think. Here are answers to ten questions to ask before installing a cloud-based monitoring system:

  1. What is required to use a remote monitoring system?

Most remote monitoring systems require an internet or WiFi connection and access to an electrical outlet. Programming is done through a website, so it’s easiest to use a computer for the initial setup. If you don’t have an internet connection at your location, you’ll want to choose a cellular system. Make sure that there’s sufficient signal strength at your site, and check the signal quality in the area before purchasing a cellular device.

2. How do we determine what kind of monitoring system and sensors we need?

A reputable manufacturer will have a well-trained support team that can assess your needs even without a site visit to determine which products are best for your application. If you feel you need them to check out your greenhouse operation,many companies can set up a video conference or FaceTime chat to substitute for being on site.

You will want to provide details about the scope and purpose of your cannabis growing operation. Important factors to discuss include:

  • Skeletal structure of the greenhouse (metal, plastic, wood, etc.) and the covering material (glass or plastic).
  • Floor space square footage and height of each of your greenhouses.
  • Number of greenhouse structures in your operation.
  • Outdoor climate to determine if you rely more on heating or air conditioning and the level of humidity control needed.
  • Space dedicated to phases of growth (cloning and propagation, vegetative, flowering) and the microclimates needed for each.
  • Types of lighting, ventilation and irrigation systems.
  • Level of technological automation versus manual operation in place.

The monitoring system representative will then determine the type of system that would best serve your operation, the number of base units you will need and the types of sensors required.

Image 2: Temperature display provides quick view of sensor data
Temperature display provides quick view of sensor data

The representative should also be able to provide tips on the placement of the sensors you’re purchasing. For example, to ensure thorough air temperature coverage, place sensors throughout the greenhouse, next to the thermostat controlling the room temperature and in the center of the greenhouse out of direct sunlight.

Note that there shouldn’t be a cost for a demo, consultation or assistance throughout the sales process. Be sure to ask if there are any fees or licenses to keep using the monitoring equipment after you purchase it.

3. Are sensors included with the monitoring system?

In most cases, sensors are sold separately. The sensors you select depend upon the conditions you want to monitor and how many you can connect to your base unit. Certainly, temperature is critical, but there are many other factors to deal with as well, such as humidity, CO2, soil moisture, water pH, power and equipment failure, ventilation and physical security.

For example, humidity has a direct impact on the photosynthesis and transpiration of plants. High humidity can also cause disease and promote the growth of harmful mold, algae and mildew. Sensors can detect changes in humidity levels.

Image 3: Water pH sensor
Water pH sensor

Like any other plant, cannabis needs COto thrive, so it’s a good idea to include a COsensor that will signal to the monitoring device when readings go out of the preset range. There are even sensors that you can place in the soil to measure moisture content to help prevent over- or underwatering, budget water usage costs, promote growth and increase crop yield and quality.

Of course, all the critical systems in your growing facility—from water pumps to irrigation lines to louvers—rely on electrical power. A power outage monitoring sensor detects power failure. It can also monitor equipment for conditions that predict if a problem is looming, such as power fluctuations that occur at specific times.

Ventilation systems not only help control temperature, they also provide fresh air that is critical to plant health. Automated systems include features like vented roofs, side vents and forced fans. Sensors placed on all these systems will send personnel an alert if they stop running or operate outside of preset parameters.

To monitor the physical security of your greenhouses, you can add sensors to entrance doors, windows, supply rooms and equipment sheds. During off hours, when no staff is on duty, you can remain vigilant and be alerted to any unauthorized entry into your facility.

4. Do monitoring systems only work with the manufacturer’s sensors?

Not necessarily. For example, certain monitoring units can connect with most 4-20mA sensors and transmitters regardless of the brand. When selecting sensors, you might have a choice between ones that are designed by the manufacturer to work specifically with the monitoring system or universal components made by a third party. If the components aren’t made by the system manufacturer, you’ll want to find out if they have been tested with the monitor you are choosing and if you need to work with another vendor to purchase the parts.

A humidity sensor mounted in a weatherproof enclosure
A humidity sensor mounted in a weatherproof enclosure

5. Is a monitoring system easy to set up, or do we need to hire an electrician?

Many monitoring systems are quick and easy to install, and users can often set them up without hiring an outside expert. Look for one that requires only a few simple physical installation steps. For example:

  1. Mount the device to the wall or somewhere secure;
  2. Plug it into an electrical outlet and an internet connection;
  3. Connect the sensors.

You connect the sensors to the base unit’s terminal strip using wire, which is included with many sensors. The range of many wired sensors can be extended up to 2,000 feet away from the base unit by adding wire that can be easily purchased at any home store. It’s a good idea to hire an electrician if you need to run wires through walls or ceilings.

Usually, once you plug in the device and connect the sensors, you then create an account on the manufacturer’s designated website and begin using your device. There should be no fee to create an account and use the site.

If the manufacturer doesn’t offer installation services, ask if they can recommend a local representative in your area who can set up your system. If not, make sure they provide free technical support via phone or email to walk you through the installation and answer any questions you might have about programming and daily usage.

6. Is there a monthly fee to access all the functionality of a monitoring device?

Many web- or cloud-based systems provide free functionality with some limitations. You might have to purchase a premium subscription to unlock features such as text messaging, phone call alerts and unlimited data logging access.

 7. Should we get a system that is wired or wireless? Will we need to have a phone line, cable, internet or something else?

Wireless can mean two different things as it relates to monitoring: how the system communicates its data to the outside world and how the sensors communicate with the system.

The most popular systems require an internet or WiFi connection, but if that’s not an option, cellular- and phone-based systems are available.

A hardwired monitoring system connects the sensors to the base device with wires. A wireless system uses built-in radio transmitters to communicate with the base unit. Some monitoring systems can accommodate a combination of hardwired and wireless sensors.

8. Can one system monitor several sensor inputs around the clock?

Once the monitoring system is installed and programmed, it will constantly read the information from the sensors 24/7. Cloud-based systems have data logging capabilities and store limitless amounts of information that you can view from any internet-connected device via a website or app.

If the system detects any sensor readings outside of the preset range, it will send an alarm to all designated personnel. The number of sensors a base unit can monitor varies. Make sure to evaluate your needs and to select one that can accommodate your present situation and future growth.

When a monitoring system identifies a change in status, it immediately sends alerts to people on your contact list. If you don’t want all your personnel to receive notifications at the same time, some devices can be programmed to send alerts in a tiered fashion or on a schedule. Multiple communications methods like phone, email and text provide extra assurance that you’ll get the alert. It’s a good idea to check the number of people the system can reach and if the system automatically cycles through the contact list until someone responds. Some systems allow for flexible scheduling, so that off-duty personnel don’t receive alerts.

9. Do monitoring systems have a back-up power system that will ensure the alarming function still works if the power goes out or if someone disconnects the power?

The safest choice is a cloud-based system that comes with a built-in battery backup that will last for hours in the event of a power failure. Cloud-based units constantly communicate a signal to the cloud to validate its online status. If the communication link is interrupted—for example by a power outage or an employee accidently switching off the unit—the system generates an alarm indicating that the internet connection is lost or that there is a cellular communications problem. Users are alerted about the disruption through phone, text or email. All data collected during this time will be stored in the device and will be uploaded to the cloud when the internet connection is restored.

If you opt for a cloud-based monitoring system, make sure the infrastructure used to create the cloud platform is monitored 24/7 by the manufacturer’s team. Ask if they have multiple backups across the country to ensure the system is never down.

10. What should we expect if we need technical support or repairs to the system?

Purchase your system from a reputable manufacturer that provides a warranty and offers full repair services in the event the product stops working as it should. Also, research to make sure their tech support team is knowledgeable and willing to walk you through any questions you have about your monitoring system. Often, support specialists can diagnose and correct unit setup and programming issues over the phone.

It helps to record your observations regarding the problem, so the tech team can look for trends and circumstances concerning the issue and better diagnose the problem. Ideally, the manufacturer can provide loaner units if your problem requires mailing the device to their facility for repair.

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Are LED Grow Lights Worth It?

By Dr. Zacariah Hildenbrand, Robert Manes
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There really is no question that Light Emitting Diodes (LEDs) work, but just how well do they work?

For the last 50+ years, indoor cannabis cultivators have used High Pressure Sodium (HPS) lights to illuminate their flowering crops. This technology was developed for, and is still used, as street lighting and there really hasn’t been a fundamental change to the output in the last half century.LED technology showed great promise to solve some of the primary drawbacks to the use of HPS technology for indoor cannabis cultivation. 

We are often asked why this technology was used to grow cannabis, and the answers are simple: 1) due to strict legislation and even stricter penalties for growing cannabis, growers wished to move their crops indoors, and, 2) there really hasn’t been another technology that would allow us to cheaply place 400, 600, or even 1000W of light on a crop. In addition, HPS technology is rich in certain frequencies of red light, which is so important to flowering crops. Unfortunately, HPS lamps have their drawbacks, such as high heat output and lack of other “colors,” along the lighting spectrum. In fact, up to 95% of light produced by an HPS lamp is emitted in the infrared range, which we perceive as heat.

Enter the Light Emitting Diode. LED technology showed great promise to solve some of the primary drawbacks to the use of HPS technology for indoor cannabis cultivation. The ability to manipulate spectrum, precision delivery of light, elimination of dangerous heat, and lack of substantive toxic chemical makeup are a few reasons to deploy LEDs. However, as with any new technology, there were some significant hurdles to overcome.

Early experimentation using Light Emitting Diodes (LEDs) to grow cannabis, suffice to say, did not go well.  Poor performance, misleading advertising and equipment failures plagued the first mass-produced LED grow lights. The aspect of poor performance can be blamed on several factors, but the most prominent are very low efficacy, in terms of light produced per Watt consumed, and incorrect application of spectrum (color) for horticultural purposes. Causes of “misleading advertising” was a mixed bag of dubious sales pitches and lack of understanding the technology and of horticultural lighting requirements. Additionally, there certainly were some quality control issues with LEDs and electronics equipment in general, especially from offshore manufacturers in China and Korea.

A plant in flowering under an LED fixture

That legacy of poor performance still has a partial hold on the current indoor cannabis cultivation industry. Many of the current “Master Growers” have tried LEDs at some point and for the various reasons mentioned above, reverted to HPS lighting. Some of this reluctance to embrace LEDs comes from unfamiliarity with application of the technology to grow better cannabis, while some can be attributed to stubbornness to deviate from a decades-long, tried-and-true application of HPS lighting.

Certainly, growing with LEDs require some changes in methodology. For instance, when using true “full spectrum” grow lights, more nutrients are consumed. This is caused by stimulation of more photoreceptors in plants. To further explain, photoreceptors are the trigger mechanisms in plants that start the process of photosynthesis, and each photoreceptor is color/frequency-dependent. True full spectrum LED systems fulfill spectrum shortages experienced with HPS technology. Anyone that grows with LEDs will at some time experience “cotton top,” or bleaching at the upper regions of their plants.  Increased nutrient delivery solves this issue.

As we continue to uncover the vast medical potential of cannabis, precise phytochemical composition and consistent quality will become all-important.While the industry is still saturated with confusing rhetoric and some poorly performing equipment, LEDs are gaining momentum in the cannabis market. LED efficacies have increased to levels far greater than any other lighting technology. Broad spectrum white and narrow-frequency LEDs in all visible (and some invisible to the human eye) colors are being produced with great precision and consistency. Quality control in manufacturing is at an all-time high and longevity of LEDs has been proven by the passage of time since their introduction as illumination sources.

As the world embraces LED horticultural lighting, probably the most encouraging news is that current and upcoming generations of cannabis growers are more receptive to new ideas and are much more tech-savvy than their predecessors. Better understanding of cannabis-related photobiology is helping LED grow light manufacturers produce lighting that increases crop yields and perhaps more importantly, cannabis quality. As we continue to uncover the vast medical potential of cannabis, precise phytochemical composition and consistent quality will become all-important.

Obviously, the indoor cannabis industry is expanding rapidly and this expansion raises deep environmental concerns. More power is being used for indoor lighting, and for the cooling required by this lighting. Power systems are being taxed beyond forecasts and in some cases, beyond the capabilities of the infrastructure and power companies’ ability to produce and deliver electricity.  Some states have proposed cannabis-related legislature to limit power consumed per square foot, and some are specifically requiring that LEDs be used to grow cannabis. While some business leaders and cultivation operators may groan at the acquisition cost and change in operating procedures when deploying LEDs, common sense states that it is imperative we produce cannabis applying the most environmentally friendly practices available.

Operational Inefficiencies in Commercial Cannabis Cultivation

By Drew Plebani
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From the perspective of sustainable cannabis cultivation models, it seems clear that outside of the particular cultivation methodology adopted, that operational efficiency and the implementation of lean manufacturing principles will be necessary for successful and truly “sustainable” businesses, in the current, ever growing, cannabis space.

Implementing lean manufacturing principles as an integral part of the cannabis cultivation facility just makes sense- it is a manufacturing operation after all. From a lean perspective, doing away with the non-value-added costs in the supply chain and production model are quite important.

Let’s look at this case study as evidence for the necessity of operational efficiency:

A 300-light flowering, indoor cultivation facility in Colorado.

The system was purchased with ongoing pest/disease issues, recent updates to Colorado’s approved pesticide list, had prompted the implementation of an updated integrated pest management (IPM) program, which had been moderately successful in developing an albeit short-term solution to keeping ongoing root aphids, powdery mildew, and botrytis, to name a few, at bay.

This existing facility was producing roughly 60 pounds of trimmed cannabis per week, equivalent to almost $6M annual gross, however they were losing a percentage of their yields to product that did not pass Colorado’s contaminant testing requirements.

It is important to note that any deviation from the existing manufacturing schedule and system would create a change to the potential productivity of the system, for better or worse.

At the most basic level, one would hope that a new operator taking over an existing facility would analyze the system and implement incremental or perhaps major changes to create more efficient and profitable outcomes. That being said, currently the average grower likely doesn’t have much understanding of the lean manufacturing process. That will undoubtedly change.

When we look at basic manufacturing facility operations, on an annual gross potential basis, each daily task not completed on the existing manufacturing timeline is, at least, a 0.3% (1/365) loss in potential productivity. In monetary terms, for this particular facility, each 0.3% equates to a potential $18,000 in lost productivity.

The information that follows is taken from observations during the first week of this facility ownership transition and below is a generalized outline representing just one aspect of the operational inefficiencies (created or existing) that were observed :

  • Plant group A put into flowering 4 days behind schedule (4 days x 0.3%) =1.2%
  • Plant group B transplanted 3 days behind =0.9%
  • Plant group C transplanted 7 days behind =2.1%
  • Plant group D (clones) taken 7 days behind =2.1%
  • IPM applications not completed for 7+ days

That equals a 6.3% loss in potential annual productivity, which translates into a rough estimate of up to $378,000 in lost revenue.

Changes to the nutrient program in the midst of the plant’s life cycle had created nutrient deficient plants in all stages of vegetative and flowering growth, coupled with changes to the existing IPM program, all add to the potential losses incurred. Deviations in the plant nutrition program and IPM scheduling are hard to quantify mid-cycle, but will certainly be quantifiable when the hard numbers come home to roost.

These inefficiencies, once compounded, could potentially equal more than a 20% loss in potential productivity during the subsequent 3.5 month plant cycle. The current 60 pounds-per-week would likely be reduced for the next 2 months, down to roughly 50 pounds, or even much less, per-week. This could become a loss upwards of $500,000 in annual potential revenue in the first quarter of operation alone.

These seemingly small and incremental delays in the plant production cycle are all greatly compounded. The end result is that each subsequent cycle of plants is slightly smaller due to delays in transplanting and less days at maximized vegetative growth, etc. Undoubtedly, the cumulative effect of these operational inefficiencies creates a significant drop in the existing level of productivity, with the end result being a significant, undesired loss of revenue.

The sum of the lessons learned from this cultivation facility, is this: a sustainable operation, in the most pragmatic sense, is an efficient one both in terms of productivity and in terms of the carbon footprint and waste generated. The more streamlined and successful the operations are, the greater likelihood of success. Perhaps all of this is to say don’t forget about all the little parts that make up the whole, and strive to create a work environment/corporate culture that empowers your employees, your managers and all involved to participate and contribute to the process of improving the operations for mutual benefit.

Lessons learned from the aerospace manufacturing industry: Even the smallest zip tie on a spaceship matters! Some food for thought: If it’s truly beneficial it should stick around… If it is beneficial and it’s not sticking around, then there are limiting factors in the system that need to be addressed.