One of the more stressful parts of planning a vacation is packing for air travel. What comes and what stays requires careful strategy because suitcase space and weight are everything.
The same is absolutely true for cooling towers. There is only so much space available and weight a roof can take. The tower, the foundation on which it sits, and the equipment needed for installation all draw on the precious, limited commodity of weight.
A surprising source of extra weight in a cooling tower requires a look inside the tower. While some newer materials have replaced traditionally heavy components, heavy cooling elements — coils and condensing units — remain a source of extra weight.
The Weight of Compromise
Old-fashioned coils and condensing units were made of metals that were highly susceptible to rust and corrosion. This reduced the efficiency of the tower, created a welcoming environment for scale and biofilm, and required a ton of maintenance and replacement.
The industry soon replaced these rusty materials with bacteria- and rust-resistant materials, like copper and stainless steel, with similar weights. A typical closed-circuit cooler weighs approximately twice as much as an open-loop cooling tower in the same box size.
This weight isn’t just a problem for total rooftop weight; it also complicates maintenance. Heavy metal coils take many days to transport to sites on 18-wheeler trucks, and they must be unloaded and put in place using cranes. Numerous, heavy, metal coils are many stories in the air, inside the tower on top of a building. This makes changeout for cleaning or maintenance logistically tricky at best and unsafe at worst.
When weight is so precious, polymers offer a lightweight alternative to copper and stainless steel coils. Like their copper and stainless steel cousins, polymer coils are innately corrosion-resistant and resist scaling and fouling. A closed-circuit polymer cooler is about 15% heavier than its open-loop sister but is 50% lighter than its competition in a similar box size. Polymer coils need to be replaced less frequently than metal. When changeout is necessary, the coil can easily be removed, lifted, and replaced without large cranes or lifting equipment. At 12 pounds, they are light enough that they can be shipped by general mail and be lifted and installed by hand in most cases.
But, unlike these metals, polymer coils bring additional benefits, including:
• Less chemical treatment and cleaning to maintain peak performance;
• Less maintenance because they are more corrosion-resistant than metal;
• Greater resiliency and redundancy because they are impact resistant and modular; and
• High heat transfer performance: the pressure drop through polymer coils with process water is up to 50% less than metal coils.
Shed the Extra Weight
Polymer elements in cooling towers — or entire towers made of composite materials, like Fiber Reinforced Polymer (FRP) — can reduce the weight by up to 50%. Polymer coils do all the work of metallic coils without adding extra weight or expense. When weight is a scarce resource, the lighter the better. With polymer coils, you can lose weight without losing performance.
Research cooling tower options and their internal components today — long before it’s time for an emergency replacement — so you can find the very best tower for your needs.
