4 Mistakes That Can Jeopardize Your Cannabis Grow Room Project
Photo courtesy of Quest

4 Mistakes That Can Jeopardize Your Cannabis Grow Room Project

A look at some of the most serious errors and how you can avoid them.


Editor’s Note: This article has been adapted from Chapter 10: Mistakes That Can Jeopardize Your Project from Getting Grow Rooms Right, written by Geoff Brown, Quest’s VP of Technical Solutions, and Dan Dettmers, Quest’s Applications Engineer.

Unlike many other subjects in the construction field, information is scarce when it comes to grow room designs and control practices. As a result, there are common mistakes that can be made by almost anyone—mistakes that hold the potential to limit your grow room project’s success. The consequences of these oversights vary, but in all cases, they could possibly damage your long-term viability by reducing your business effectiveness, increasing your operating expenses, reducing your crop output and quality or posing various other problems.

Here, we review some of the most serious errors and how you can avoid them in your cannabis grow room project.

1. Not Understanding and Articulating Your Desires

Many problems that can happen in a project trickle down from the fact that people involved in the project are not entirely clear on what kind of results the grower is seeking.

It’s very important that you nail down early in the project exactly what it is you’re looking for, why you’re looking for that, and communicate it clearly. Grower expectations can vary quite a bit depending on the type of facility and intended final use of the product. What is needed for fine bud may not be the same as what is required for oil extracts. As a result, key design factors such as the type and intensity of lighting and temperatures/humidity levels for each room must be agreed upon by all involved parties. These operating conditions form the basis for all other aspects of the design as well as the capital, operating and maintenance costs of equipment required to maintain desired conditions.

Considering different product purposes and grower expectations, clearly there is not a “one size fits all” formula for the “perfect” or even “standard” grow facility. Each project should be approached with a blank slate and designed with specific goals in mind.

Ensure that you have every aspect of the space conditions and related factors agreed upon before you move into the design phase, in what’s called a “design intent” document, created by the engineer. This is the only way to ensure that the project will meet grower expectations and stay within the allocated budget.

The first and single most important step in grow room design is for all parties to meet during the preliminary stages. By involving everyone from the start, you can clarify expectations for the project at the initial stage. This vital step ensures that everyone is on the same page and lays the foundation to keep the project on track. An initial meeting is both time and cost effective, plus it goes a long way in establishing a good working relationship with everybody involved in the project.

Do not use “expected” operating conditions from a generic table. Everyone should take the time to review the requirements of this specific grow room. It’s important to be aware that some facilities operate with temperatures and humidity requirements outside of what we would generally consider standard. It is essential to recognize that different grow rooms may call for different conditions either due to their strain, plant species or intended purpose.

When expectations have been expressed and are understood by everyone involved in the design process, it’s time to figure out which solutions can satisfy the requirements.

The operating budget needs to be considered in the planning stage. Every cost, from energy to water, materials to maintenance, should be factored in.

If for some reason the projected operating costs are higher than the available budget, you might have to go back to the drawing board and determine what you can adjust to bring costs back down. Remember that energy costs will be volatile over time and inflation will also have its impact. To play it safe, it’s advisable to make sure that the operating costs fall well within the budget and do not reach the upper end of what’s affordable. This is also why it’s very important to strive for energy-efficient equipment as it provides more predictability in the long term.

Once the operating conditions are agreed on by all involved parties, make sure to create a document regarding the exact conditions to serve as a reminder of what was agreed. If expectations are not firmly decided on and communicated, the grower could end up with the wrong solutions for their needs.

2. Misguided Value Engineering

Value engineering is a technique used in project management that seeks to decrease the purchase price of equipment. Ideally, it would result in a product that costs less but delivers the same performance as a more expensive option.

Value engineering is often used in a budget crunch to bring down the price of HVAC equipment in grow rooms through the elimination of several key functions that contribute to a good environment. The thinking is that, while these features are important, they are not technically required for the unit to operate. But this represents a profound misunderstanding of how these features work and the value of having them in place.

There is also a misunderstanding of the difference between first-cost and total cost of ownership. Often, in the bid and procurement process, there is a motivation to obtain equipment at the lowest possible first-cost. However, this analysis neglects the overall investment of buying equipment which, if done correctly, will pay dividends for many years in reduced costs for operating and maintaining the unit.

Selecting equipment for a grow room is an investment in the facility. Spending more allows you to get better equipment that offers more high-performance features that improve efficiency and longevity. Just like any other product, there are HVAC manufacturers that offer cheaper, but inferior, products. Avoiding this low-quality equipment is important if you’re aiming for a high-performing facility.

While value engineering is a legitimate technique to use when there is a limited capital budget in place, everybody involved in the project should understand the dangers of seeking only the lowest bid.

The optimal balance of capital-cost, installation costs, and maintenance and operating costs will deliver outstanding return-on-investment for the grower. First-cost is, simply, the initial cost to buy the equipment. It considers factors like whether there are any add-on features to the HVAC (like economizer cooling or heat recovery) and can vary depending on the brand and quality of equipment. First-cost can also be called capital cost and that is usually how it’s expressed in a budget line.

Installation carries its own costs that need to be carefully considered in the total purchase price. Total cost of ownership is everything that happens after first-cost, such as the cost of energy to run the unit, the effort required to maintain it, whether the grower will need expensive repairs, and how soon the unit will need replacement. Total cost of ownership can easily, over time, eclipse the first-cost of some equipment. Therefore, both of these costs must be estimated and considered before making any buying decisions. Spending more on the front-end (CAPEX) can avoid greater costs on the back-end (OPEX).

The grower should get involved in the procurement of their equipment because they will be saddled with the long-term costs associated with whatever is purchased. They need to understand what the cost breakdown is for all the equipment that’s being considered in order to decide what works best for their business objectives. The grower should ask many questions and make sure they are being told the reasons for certain equipment recommendations and existing alternatives.

There are some features for HVAC that are considered “optional” add-ons. These may include economizer cooling and heat recovery. These features may be eliminated to pare down the cost of equipment. But does it really result in the same performance? And is eliminating some of these features a smart investment?

Another important issue to consider that is easily forgotten is how much maintenance the selected equipment will require. Every piece of equipment needs some attention periodically. But cheaper equipment can require closer attention than those of a higher grade. By choosing higher-quality components that are more efficient and require less annual maintenance, facilities can realize greater profit over time.

3. Don’t Take a Piecemeal or Band-Aid Approach

Creating a grow facility needs to be a holistic process that considers all the systems as contributing to one environment.

The grower needs to have a plan for how they’re going to tackle every aspect in the near and long term. Most growers build their facilities in multiple stages, which is a smart way to go, but there needs to be come detailed central planning behind it. Know how you’re going to scale that first phase after it’s built.

It’s also important that everything be ready when it’s time to hit the “on” switch, figuratively speaking. If you try to get started, for example, with your HVAC equipment but the building management software is not yet operational, there could be serious problems that occur as a result of launching a half-baked system.

The same goes for relying on cheap band-aid solutions for problems entirely created by short-sighted decisions in the design process. An example of this are extra fans many growers have added to their grow rooms to increase air churn because the HVAC specifications are insufficient to provide the turnover a grow facility needs. While they do improve the churn, it comes at a cost of adding more heat into the space, something often not accounted for in the cooling load calculations.

4. Don’t Pick Vendors—Pick Partners

Picking someone who is looking to be a vendor to you, and not a partner, is a potential mistake for your business.

A partner in this sense means someone you work with who genuinely has your company’s best interests in mind. You should choose someone who is invested in working with you for the long haul to ensure your total success.

Partners understand your business, including all aspects, not just the particular area they deal with. Partners want to help solve your problems. They should also be willing to provide advice based on their experience, even if it means there may be no sale in the end. Partners are willing to make what they sell work for you, and keep it working for the long term.

When you have found one you trust, put that trust where it matters and collaborate with them on whatever solution they are providing. There is certain key information you need to provide to an HVAC partner to allow them to investigate the right equipment for your needs. Because of the proprietary nature of this business, most growers would only feel comfortable about discussing some of these details with someone they trust—a partner, not just any vendor.

Listen to your partner’s recommendations, particularly when it comes to installing their equipment and interfacing it with your grow rooms. Not all solutions are the same, and what may have worked in a previous phase or with previous equipment may not work the same way with new gear. Just as how the master grower knows about their plants, manufacturers know about their equipment. This work requires a high level of trust and confidence in each other, which is why it’s so important you find a manufacturer you can consider a partner.

Dan Dettmers is an Applications Engineer at Quest and its Controlled Environmental Agriculture division. Before Quest, Dettmers dedicated over 20 years to research and instruction at University of Wisconsin-Madison, primarily in industrial refrigeration for food and pharmaceutical processing. In his current role, Dettmers leads efforts to develop more efficient methods for handling latent loads and improving the air quality for cannabis and all controlled environmental agriculture operations. He is a contributing member to The American Society of Agricultural and Biological Engineers (ASABE) X653 guideline “Heating, Ventilating, and Air Conditioning (HVAC) for Indoor Plant Environments without Sunlight.”

Geoff Brown started his HVAC career over 15 years ago and has honed his expertise, dealing in every aspect of dehumidification throughout his career. Prior to his position with Quest, Brown was a senior sales manager and sales engineer, who consulted on and managed various successful dehumidification projects. As one of North America’s leading authorities on HVAC for grow rooms, Brown participates in various advisory boards in the cannabis industry and is a contributing member to ASABE X653 guideline “Heating, Ventilating, and Air Conditioning (HVAC) for Indoor Plant Environments without Sunlight."