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Buyer's guide · 9 min read

Cooling tower selection and water treatment in Florida

Selecting a cooling tower means matching heat-rejection capacity to the chiller plant, choosing a tower type and material that survive Florida’s climate and water chemistry, and committing to a water-treatment program that controls scale, corrosion, and biological growth — including Legionella. The tower is the cheap part; the treatment and maintenance are the lasting commitment.

Section 01

What the tower has to do

A cooling tower rejects the heat a water-cooled chiller removes from the building, using evaporation. Tower capacity is matched to the plant’s heat-rejection load at design wet-bulb conditions — and in Tampa Bay the design wet-bulb is high, which directly affects how much tower you need.

Undersize the tower and the chiller’s efficiency and capacity suffer on the hottest, most humid days — exactly when the building needs them most.

Section 02

Tower types and materials

Towers come in induced-draft and forced-draft, crossflow and counterflow configurations, with materials from galvanized steel to stainless to fiberglass and engineered plastics. In Florida’s heat, humidity, and — near the coast — salt air, corrosion resistance matters, and the cheaper material can be the more expensive choice over a 20-year life.

Selection balances first cost, footprint, efficiency, sound, and durability in the local environment.

Section 03

Water treatment: the real commitment

Tower water concentrates minerals as it evaporates, so it must be treated continuously to control three things: scale (mineral deposits that insulate the condenser and kill efficiency), corrosion (which destroys equipment), and biological growth (slime and bacteria that foul surfaces and create health risk).

This is an ongoing chemical-treatment program with monitoring, not a set-and-forget item. It is the single biggest operational difference between a water-cooled and an air-cooled plant.

Section 04

Legionella risk and management

Cooling towers can aerosolize water, and warm tower water is a known environment for Legionella bacteria. Responsible operation follows a water-management plan — the approach described in ASHRAE Standard 188 — with treatment, monitoring, and documentation to control the risk.

This is a genuine public-health and liability matter. Any owner running a tower should have a written water-management program and a treatment vendor, not an informal arrangement.

Section 05

Blowdown, makeup, and water cost

Towers lose water to evaporation and drift, and they intentionally discharge concentrated water (blowdown) to keep mineral levels in check, replaced by fresh makeup water. That water use is a real operating cost and, in some jurisdictions, a conservation or permitting consideration.

Efficient treatment maximizes cycles of concentration — how many times water is reused before blowdown — which reduces both water and chemical consumption.

Section 06

Is a tower the right call?

A cooling tower pays off when the efficiency of a water-cooled plant outweighs its complexity — generally on larger, steady loads with an owner equipped to maintain treatment. Where water is costly or restricted, mechanical space is tight, or maintenance capacity is thin, an air-cooled approach may be the better total-cost choice.

That tradeoff is the heart of air-cooled vs water-cooled chillers — the decision the tower question sits inside.

Operator FAQ

Quick answers

How is a cooling tower sized?

Tower capacity is matched to the chiller plant’s heat-rejection load at the design wet-bulb temperature. In Tampa Bay the design wet-bulb is high, so the tower must be sized for it — undersizing hurts chiller capacity and efficiency on the hottest, most humid days.

What does cooling tower water treatment control?

Three things: scale (mineral deposits that insulate the condenser and cut efficiency), corrosion (which destroys equipment), and biological growth including Legionella. It is a continuous chemical-treatment and monitoring program, not a one-time task.

Are cooling towers a Legionella risk?

They can be. Warm tower water can host Legionella and towers can aerosolize water, so responsible operation follows a written water-management plan — the approach in ASHRAE Standard 188 — with treatment, monitoring, and documentation to control the risk.

How much water does a cooling tower use?

Towers lose water to evaporation and drift and discharge concentrated water as blowdown, all replaced by makeup water. The amount depends on load and cycles of concentration; good treatment maximizes reuse before blowdown, lowering both water and chemical use.

Get help

Planning a commercial HVAC project in Tampa Bay?

Suncoast Cold Systems delivers commercial HVAC design-build across Tampa, St. Petersburg, Clearwater, Brandon, Riverview, Temple Terrace, and Wesley Chapel — load calcs, equipment selection, layouts, controls, install, and commissioning under one contract. Licensed Class A A/C Contractor (FL #CAC1824642), with a Florida PE of record on sealed work.

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