If you work in the refrigerated building industry long enough, it’s bound to happen—high levels of humidity will find a way to cause all kinds of problems in the facility.

Whether it’s moisture ruining food products or ice creating safety issues, it’s rare for a humidity problem not to strike at some point. That’s why knowing the symptoms of high humidity and how to address it is critical. For years, many plant operators have tried an assortment of “fixes,” only to waste time and money.

Before jumping into the solutions, it’s important to be aware of the symptoms.

Know the symptoms of high humidity

In the cold chain, frost and condensation are the tell-tale signs that there’s a humidity problem. That may seem obvious, but sometimes folks simply assume it’s just a byproduct of working in cold environments where moisture is present, opting to ignore it rather than address it.

It’s important to also look for:

• Frost buildup on ceilings, walls and racking
• Ice buildup on the floor
• Excessive frost load on evaporators
• Dripping condensation
• Ice/frost on refrigeration system components
• Wet ceilings and staining

Additionally, mold and mildew are clear signs that you a humidity problem exists. However, they’re generally more common in smaller facilities where resources to address humidity problems aren’t as readily available. Mold and mildew are signs of an advanced humidity problem, where someone has missed the warning signs of high humidity and frost.

Develop holistic humidity solutions

It’s best to approach humidity problems with a degree of thoroughness and attention to detail, while simultaneously working to simplify and provide the most efficient solution for each project.

After spending time understanding the details of a facility, including its size, production process, primary symptoms and the HVAC&R design, there are several steps to improve the situation, many of which work in conjunction with desiccant dehumidification.

Walk through the entire design with a contractor and try to offer multiple solutions, ask them what they’ve tried. Also, work within the parameters specific to the problem to create customized solutions.

1.Adjust temp set points on evaporators

Is the problem due to an operational change to the space, or could an adjustment to evaporator temperature solve the issue? Always explore operational set point changes to alleviate the issue before buying equipment.

2.Door management

This may sound obvious, but it’s one of the trickiest areas for cold chain facilities to manage. Whether it’s a torn strip curtain or a door propped open, doors need to be properly maintained and used properly.When issues of frost buildup or infiltration still exist, a small desiccant dehumidifier can provide a localized solution.

3.Investigate air balance for the problem area

Determine the source of the moisture. Often, the moisture originates elsewhere and is drawn into the problem area by an air balance issue.
 

4.Capture the moisture before it reaches the problem area

If preventing the moisture from entering a problem area is impossible, why not address it at its source? One fix is to place a refrigerant dehumidifier in an adjacent room, which may be contributing to the moisture problem. Once humidity is controlled in that space, it can stabilize the relative humidity in the cold chain facility.

Desiccant dehumidifiers to the rescue

Once you’ve optimized a facility by working through the steps above, add desiccant dehumidifiers as needed, rather than trying a handful of other solutions that may or may not work.

Historically, contractors don’t like the idea of adding more equipment to a design. But, a majority of the time, they’re going to need them regardless, so it’s best to avoid wasting time and money and install them sooner rather than later.

Another reason desiccant dehumidifiers aren’t the first option is that sizing and pricing have been a mystery to contractors. But, that’s different now because contractors want to be transparent about how they size and work with customers to solve issues. Often it’s a back-and-forth to help customers be informed and know how the solution was designed. That means you don’t have to just hope the money you’re spending on dehumidifiers will fix the problem.

Also, some desiccant dehumidifiers are easier to work with now. For instance, some come modular, meaning each unit can be upgraded to handle more capacity as needed.

That’s a significant feature because rather than having to replace units, you can swap a few parts and handle more humidity with the same dehumidifier.