The hidden costs of blocked airflow in the greenhouse

Sylvia Courtney, VP of Design at LLK, has walked into countless facilities where the layout looked perfect on paper… until operators started using the space. What she finds most often isn't a design flaw. It's a storage problem masquerading as a cooling problem.

"The biggest thing I've seen often is growers using the corridor as a storage facility," Courtney explained. And it's not just taking up space, it's directly impacting system performance and operational costs.

The corridor isn't a warehouse
In facilities with evaporative pad systems, corridors serve a critical function: they're the pathway for air intake. Block that pathway, and the entire cooling system suffers.

"They're placing pallets of soil right in front of the intake for the pad systems. In some cases, they may even put a cabinet," Courtney noted. "Anytime we block the flow, it reduces the efficiency of the cooling system if we're using a fan and pad system."

The logic seems sound from a labor perspective: store materials close to where you'll use them. But the hidden cost shows up in your climate control bills and crop performance.

Courtney has seen it taken even further: "Some places where they have pallets, they also have potting benches, and so all the dirt and dust from the potting bench gets sucked into the pad system, and it impacts the performance."

When convenience becomes costly
Operators sometimes justify these placement decisions as labor efficiency. After all, if you're potting plants, why not do it right there in the corridor near your growing space?

"They see it as labor efficiency because they're doing the potting right there close to where they are," Courtney says. "But then there's a converse effect of, you know, reducing the efficiencies of the performance of the cooling system."

It's a classic example of optimizing one metric while degrading another, often without realizing the trade-off you're making.

The problem extends beyond equipment and work surfaces. Even inventory storage creates issues: "I've been in a lot of school greenhouses, and they'll put a storage shelf with pots on it right in front of the fan. That isn't labor, but placing storage shelves in front of exhaust fans reduces the performance of the ventilation system."

The plant placement problem
Equipment and supplies aren't the only culprits. Sometimes it's the crop itself.

Courtney recalled visiting a facility where "they had all these really tall vertical plants right in front of the pad system, which was also blocking the [air]flow."

The principle is straightforward but often violated: "We don't want to place equipment or tall plants where it impedes the flow of air through the space. [Then] we get the ventilation that we are shooting for within that space."

Every obstruction — whether it's a pallet, a potting bench, a storage shelf, or a tall plant — forces your cooling system to work harder while delivering less. The equipment runs longer, uses more water and electricity, and might not be able to achieve your environmental targets.

Control panel placement: Another common mistake
The corridor clutter problem extends to permanent infrastructure. Control panels often end up in corridors by necessity, but their placement requires more thought than they typically receive.

"Often, the control panel may be in the corridor, and it may be on a floor stand, and often they want to put it right in front of where the pad system is. And that's never a good idea," Courtney warns.

These decisions usually happen during installation when contractors are looking for convenient locations with good access to power and communication lines. But convenience for the electrician shouldn't override system performance.

Why this keeps happening
The pattern Courtney describes isn't malicious, it's the natural result of competing priorities and limited square footage. Greenhouse space is expensive. Storage areas cost money. Labor efficiency matters.

But when you calculate the true cost of blocked airflow (higher energy bills, inconsistent climate control, increased maintenance on overtaxed systems, and potentially compromised crop quality), the "savings" from using corridors as storage areas run dry rather quickly.

The fundamental issue is that corridors don't feel like productive space. They're transitional. They don't generate revenue. So they become catch-all zones for everything that doesn't have an obvious home.

What actually belongs in corridors
Courtney says: very little.

Tools, materials, and equipment should be stored in dedicated spaces: either in a head house area or in short cabinets specifically designed not to obstruct airflow. The corridor's job is to move air efficiently, not to provide convenient storage.

Even when space is tight, blocking intakes and exhausts should be non-negotiable. These aren't just design preferences, they're functional requirements for the system to work as engineered.

The fix isn't always easy
Unlike design decisions that need to happen during initial planning, this is a problem existing facilities can address. But it requires operational discipline.

You need to audit your current corridor use and identify obstructions; create alternative storage solutions (even if it means investing in a small storage structure); train staff on why clear corridors matter for system performance; and make corridor clearance part of regular facility inspections.

The challenge is that this requires changing habits and possibly spending money on storage infrastructure you thought you'd avoided by using corridors.

Clear pathways are crucial
Your cooling system was engineered based on specific airflow assumptions. When you place pallets in front of pad intakes, install potting benches in corridors, or position storage shelves near fans, you're fundamentally changing how that system operates.

"We want optimal performance of the system so that [plants] are going to get the environment they want in that space," Courtney emphasizes.

That optimal performance requires clear pathways for air to move as designed. Storage convenience and labor efficiency matter, but not at the expense of the environmental control that makes the entire operation possible.

The solution isn't complicated: keep corridors clear, store materials in appropriate spaces, and treat airflow pathways as the critical infrastructure they are. Your cooling system (and your energy bills) will thank you.