What Does The Inside of A Closed Loop Cooling Tower Look Like

A closed loop cooling tower — also called a water cooled tower or closed loop cooling tower system — is a specialized type of water cooling tower designed to cool down process fluids (e.g., water, glycol, oil) without exposing them directly to outside air. Inside this tower is a carefully arranged system of components: sealed coils, spray water distribution, air flow, and drift-elimination. The internal structure ensures efficient heat rejection while protecting the process fluid from contamination. In this article, we explore what the interior of such a tower looks like, how each component functions, and how the system operates as a whole — with reference to MACH Cooling’s design.

Overview: What Makes a Closed Loop Cooling Tower Different

Closed Loop vs Open (Direct) Cooling Towers

• In an open cooling tower, the water to be cooled is sprayed directly into the tower and comes into direct contact with air. As a result, the water is exposed to ambient air, which can introduce contaminants, scale, or biological growth. 

• By contrast, in a closed loop cooling tower system, the fluid being cooled (process fluid) circulates inside a sealed coil (or heat exchanger) and never contacts external air. 

• The tower also contains a second loop — the “spray water + air” loop — which evaporatively cools the coil, thus indirectly cooling the fluid inside. 

This separation ensures the process fluid remains clean, free from airborne dirt, debris, and other contaminants — a major advantage for industrial, HVAC, or process-water applications that demand fluid purity. 

Because of this architecture, if you peered inside such a closed-loop (water cooled) tower, you would not see the hot process fluid directly spraying or dripping — instead you’d see coils, spray nozzles, fill media, air louvers, fans, a water basin, and other structural components arranged for indirect cooling.

 Key Internal Components & Layout of a Closed Loop Cooling Tower

Below is a schematic-like description of what you'll find inside a typical closed loop cooling tower (such as those built by MACH Cooling), along with images and a summary table.

Main Components Inside

1. Heat-Exchanger Coil (Closed Circuit Tube Bundle)

• The heart of the system — a sealed coil (made of copper, stainless steel, or galvanized steel) through which the process fluid (the fluid you want to cool) circulates. 

• Because the coil is sealed, the fluid is not exposed to outside air — preserving cleanliness and preventing contamination or fouling. 

• The coil can be arranged in a serpentine or multi-pass layout to maximize surface area and heat exchange efficiency. 

2. Spray Water Distribution System & Nozzles

• Surrounding the coil, a spray water loop sprays water over the outer surface of the coils. This spray water — not the process fluid — is what interacts with ambient air. 

• The spray helps to form a thin water film or fine droplets, increasing surface area and im

• proving heat transfer by evaporation/convection. 

• Materials for spray headers and nozzles can be PVC, brass, stainless steel depending on design and environment. 

3. Air Flow System (Fans, Louvers, Air Inlets)

• To remove heat, ambient air is drawn or forced across the coil and spray-water film. Fans (axial or centrifugal) create airflow, either as induced draft (pulling air up through the tower) or forced draft. 

• Air inlets or louvers at the bottom or sides allow fresh air into the tower housing. 

• As air moves over the wetted coil/spray, evaporation and convection remove heat; the warm, moist air then is exhausted out of the tower.

 4. Drift Eliminators & Fill Media (or Equivalent)

• A drift eliminator is installed above the coil/spray zone to catch water droplets carried upward by the airflow, preventing excessive water loss and minimizing “drift.” 

• Depending on design, the tower may also incorporate fill media or structured packing to encourage uniform distribution of spray water over the coils and maximize contact area for evaporation/heat transfer. 

5. Cold Water Collection Basin (Spray Water Basin) & Recirculation Pump

• At the bottom of the tower there is a basin ( sump ) that collects the spray water after it has cascaded down from the coils. 

• A pump draws water from this basin back to the spray distribution system, maintaining continuo

• us circulation of the spray water loop. 

• Only minimal make-up water is needed to replace what evaporates out, meaning lower water consumption than open systems, and less maintenance on the process fluid side. 

6. Tower Shell / Casing / Structural Frame

• The exterior shell or housing of the water cooled tower provides structural support, airflow channels, and protection from environment. Materials vary (FRP, galvanized steel, stainless steel, depending on design). 

• Louvers or air inlet panels at lower levels. Access doors/panels for maintenance may be included. 

Summary Table: Internal Components vs Their Function

How the Closed Loop Cooling Tower System Works (Inside View)

 Step-by-Step Inside the Tower

1. Process Fluid Enters the Coil (Primary Loop)

• The hot process fluid — which needs cooling — enters the sealed coil inside the tower. Because the coil is closed, the fluid remains uncontaminated and isolated from outside air or spray water. 

2. Spray Water & Air Work Together (Secondary Loop)

• Simultaneously, the spray pump pushes water from the basin up to the spray nozzles. This water is distributed over the coil’s outer surface. 

• Fans draw or force ambient air across the wetted coil/spray, enabling evaporative cooling and convective heat transfer. The coil wall conducts heat from the process fluid to the spray water and air. 

3. Evaporation & Heat Rejection

• As air flows over the wet coil/spray water surface, a portion of the spray water evaporates, absorbing latent heat. This removes heat from the coil, cooling the fluid inside. 

• The warm, moisture-laden air is expelled out of the tower. Meanwhile, the remaining spray water — now cooled — drips down into the basin. 

4. Recirculation & Continuous Cooling

• The cooled process fluid exits the bottom of the coil and returns to the system (chiller, process equipment, HVAC loop, etc.) for reuse. 

• The spray water collected in the basin is pumped back up, making the spray-loop continuous. Only small amounts of make-up water are added to compensate for evaporation losses. 

This two-loop, indirect cooling method ensures high thermal performance while protecting fluid cleanliness and minimizing maintenance needs.

 Why Manufacturers Like MACH Cooling Use Closed Loop Design

Using a closed loop cooling tower system (i.e. a water cooled tower / closed loop cooling tower) brings several benefits — especially for industrial, HVAC, or sensitive process applications. MACH Cooling’s product line emphasizes these advantages. According to MACH: 

• Clean Process Fluid: Because the process fluid is sealed inside the coil, it's never exposed to outside air, dust, scale, or biological contaminants. This maintains fluid purity and reduces fouling. 

• Simplified Maintenance: Only the spray-water loop requires periodic maintenance and treatment. The main process loop remains clean and tends to require less frequent cleaning. 

• Year-Round Operation & Flexibility: Such towers can operate in a variety of settings — HVAC systems, data centers, industrial process cooling (food, pharma, manufacturing), chillers, etc. 

• Efficient Heat Rejection with Lower Water Use: Because only spray water evaporates (not the process fluid), water usage is often more efficient than open-loop towers in sensitive applications. 

From the inside, a MACH closed loop cooling tower is not just a big water-spray tower — it’s a carefully engineered heat-exchange and fluid-management system that balances thermal efficiency, fluid cleanliness, water conservation, and operational reliability.

 Practical Example: Inside a Typical Water Cooled Tower from MACH Cooling

Suppose you have a water cooled tower supplied by MACH Cooling. Inside you would find:

• A robust sealed coil bundle (copper, stainless, or galvanized) through which your process fluid circulates;

• A stainless-steel or FRP casing housing the coil and all internal components;

• A network of PVC (or stainless) spray nozzles and distribution headers above the coil;

• Air inlets or louvers at lower sections; axial or centrifugal fans on the top for airflow;

• Drift eliminators installed near the air outlet to catch water droplets;

• A basin at the bottom to collect spray water, along with a recirculation pump and make-up water valve;

• Control and instrumentation (valves, sensors) to regulate spray flow, fan speed, water level — ensuring effective, stable cooling.

If you opened a maintenance hatch, you’d see the coil bundle and spray-water arrangement first; typically you wouldn’t see the process fluid, because it remains enclosed.

 Limitations & Considerations (What Inside Means for Maintenance)

While closed loop cooling towers have many advantages, understanding their internal structure is important for proper maintenance and operation:

• Spray Water Quality Matters: Since spray water contacts the coils and air, it can accumulate impurities — requiring periodic treatment (anti-scaling, anti-microbial) especially in hard-water areas.

• Drift & Water Loss Management: Even with drift eliminators, some evaporation and drift loss occurs, requiring make-up water and possibly bleed-off to prevent mineral buildup.

• Coil Inspection & Corrosion Prevention: Over time, coils may corrode or scale (depending on spray-water quality), so periodic inspection is needed.

• Fan and Pump Maintenance: Fans and pumps are essential to airflow and spray circulation — their failure can drastically reduce cooling performance.

• System Design Must Suit Application: Choosing coil material (copper vs stainless vs galvanized), spray-loop materials, and tower housing must match environmental, water-quality, and process requirements.

Conclusion

The inside of a closed loop cooling tower (or water cooled tower / closed loop cooling tower system) — such as those supplied by MACH Cooling — is a carefully engineered assembly of sealed coils, spray-water distribution, air flow, drift control, and recirculation mechanisms. Unlike open cooling towers, the process fluid remains sealed, ensuring purity and preventing contamination, while a secondary water-and-air loop handles heat rejection effectively.

Internally, you’ll find a coil bundle, spray nozzles, fans, drift eliminators, a water basin and pump, and structural casing — all working together to deliver efficient, stable cooling. This design is ideal for industrial process cooling, HVAC, data centers, and other applications requiring clean, reliable water cooling.