Cooling Tower Hire Guide for Industrial Applications
Heat rejection is one of those things nobody thinks about until it stops working. When a water-cooled system starts struggling — whether the cooling tower trips, capacity runs short during peak demand, or a planned shutdown takes the permanent unit offline — the knock-on effect moves fast. Chillers overheat. Processes stall. In data centres, industrial facilities, and large commercial buildings, that’s not a situation that can wait.
Hiring a cooling tower gives you a fast, temporary way to restore heat rejection capacity without committing to a permanent installation. What follows covers the technical side — how cooling towers work, how to size them, which type fits your application, and where most people go wrong before they call. Get those things sorted early and the right unit arrives without delays.
Temporary cooling towers installed to provide additional heat-rejection capacity at an industrial facility.
What Is a Cooling Tower and How Does It Work in Industrial Hire Applications?
Most people understand the idea but not the mechanics. A cooling tower removes heat from water through a combination of evaporation and airflow — and in most applications, it sits alongside a water-cooled chiller, pulling heat out of the condenser water so the chiller can keep doing its job.
Here’s the process. Warm condenser water flows into the tower and gets distributed over fill media, spreading it across a large surface area. Air moves through — either drawn or forced — and a small portion of that water evaporates, carrying heat with it. The cooled water then recirculates back into the system. Repeat.
The principle is straightforward. The sizing and selection side is where it gets technical.
Cooling Tower Hire: Key Technical Concepts for Sizing and Selection
Three technical concepts come up in every sizing conversation. Get any of these wrong and the problems show up quickly. Either the unit falls short and condenser water temperatures start climbing, or it’s oversized and you’re paying for capacity the site never needed. Neither outcome is good.
Wet-Bulb Temperature
Wet-bulb temperature is the number that governs what a cooling tower can actually achieve. It’s the lowest point evaporative cooling can reach under current atmospheric conditions — and it shifts with humidity. Two sites at the same air temperature can have very different wet-bulb readings depending on how much moisture is in the air. That difference shows up directly in cooling tower performance. Local wet-bulb figures matter more than most people realise when they first start the sizing conversation.
Approach Temperature
Approach temperature is the distance between the cooled water exiting the tower and the ambient wet-bulb temperature. Closing that gap — getting the cooled water closer to wet-bulb — means better performance. It also means a bigger system. Knowing what approach temperature your process actually requires is what stops you from over-specifying or under-specifying the unit.
Range
This is the temperature difference between hot water entering the tower and cooled water coming out. It tells you how much heat the tower is actually rejecting and determines whether it’s sized correctly for your load. Get the range wrong and every other spec decision gets dragged off course.
Cooling Towers vs Chillers: Understanding the Difference
This comes up regularly. Worth being direct about it.
A cooling tower and a chiller are two parts of the same system. Take one away and the other stops working properly. A chiller generates cooled water for air conditioning or process cooling. A cooling tower rejects the heat that the chiller pulls out of that water. In a water-cooled system, the chiller dumps heat into condenser water — and the cooling tower dumps that heat into the atmosphere. One generates cooling. The other removes the consequence of generating it.
| Feature | Cooling Tower | Chiller |
|---|---|---|
| Function | Heat rejection | Cooling generation |
| Role | Removes heat from condenser water | Produces chilled water |
| Dependency | Works with water-cooled systems | Can operate independently |
| Application | Industrial and large HVAC systems | Broad cooling applications |
Cooling towers support chillers. They do not replace them.
When a cooling tower goes down, condenser water temperatures start climbing. The chiller works harder, efficiency drops, and if nothing changes, it faults. That’s the sequence. It’s why a cooling tower failure often triggers a chiller problem shortly after — and why hire of both together is sometimes the right answer, not just one or the other. For chiller hire options that work alongside temporary cooling towers, see our full chiller hire range.
Types of Cooling Towers Available for Hire
Not all cooling towers are built the same. The right type depends on what your system actually needs — not just what’s available.
Open Circuit Cooling Towers
Water is directly exposed to air during the evaporation process. The most common type. Well suited to most industrial process cooling applications where direct exposure isn’t a concern. Efficient, straightforward to deploy, and the go-to for most general hire situations.
Closed Circuit Cooling Towers
The process fluid stays in a sealed loop, completely separated from the evaporating water and the air moving through the tower. The right call when contamination is a concern — pharmaceutical applications, food processing, sensitive industrial processes. If the fluid touching air is a problem, this is the answer.
Modular Cooling Towers
Modular units work well when the cooling need is temporary, predictable, or both. A planned shutdown that runs for six weeks doesn’t justify a permanent installation. Neither does a seasonal demand peak that arrives the same time every year. Modular hire fills that gap cleanly — right-sized for the period, returned when it’s done.
When Should You Hire a Cooling Tower?
From a technical standpoint, cooling tower hire is typically triggered by one of four situations. A planned shutdown or upgrade where the permanent tower needs to come offline. An emergency equipment failure where condenser water temperatures are rising and the chiller is at risk. A chiller maintenance or replacement period where heat rejection capacity needs to be maintained while the primary unit is out of service. Or a seasonal demand spike where the existing system can’t handle the additional heat load without supplemental capacity.
Sometimes the trigger isn’t sudden. A new piece of equipment gets added to the water-cooled loop. Production volumes increase. Operating hours extend. None of these individually look like a cooling tower problem — but together they push the existing tower past what it was designed for. If condenser water temperatures have been creeping upward gradually rather than jumping, that pattern is the signal. The tower is running out of headroom.
When you may not need cooling tower hire: Not every cooling problem needs a cooling tower. Small-scale applications, sites without water-cooled processes, and situations where an air-cooled chiller can handle the load — none of these require condenser water infrastructure. Worth checking which category your situation falls into before specifying anything.
How to Choose the Right Cooling Tower Hire Solution
Getting the sizing right comes down to matching thermal performance to your actual site conditions. Not ideal conditions. Not average conditions. The worst-case conditions your site is likely to see.
The inputs that drive the selection:
- Heat load in kW or BTU/hr
- Water flow rate in L/s or GPM
- Required approach temperature
- Ambient wet-bulb temperature at the site
- Available space, height limitations, and airflow clearance
- How the hire unit integrates with existing pipework and pumps
Wet-bulb is the sizing input that trips people up more than any other. It’s easy to reach for the air temperature and work from there — but dry-bulb and wet-bulb can diverge significantly depending on humidity. A tower sized on dry-bulb assumptions looks adequate on paper and falls short in practice. Size from worst-case wet-bulb for your location and the time of year the unit will be running. Not the average. The worst case.
Common Mistakes When Hiring a Cooling Tower
These come up on jobs across every industry. Most of them are avoidable — but only if the right information is in hand before the call goes in.
Sizing errors — too small or too large. An undersized tower can’t reject enough heat. Condenser water temperatures climb, the chiller gets stressed, and eventually something faults. An oversized unit just wastes energy and money. Sizing needs to come from actual heat load, flow rate, and approach temperature — not a rough guess at capacity.
Overlooking wet-bulb conditions. The most common technical mistake. A tower that performs well at 20°C wet-bulb can fall well short at 28°C. Always size for the worst ambient conditions the site is likely to see — not the comfortable middle ground.
Poor airflow placement. A cooling tower recirculating its own exhaust air will underperform regardless of how well it’s sized. Adequate clearance around the unit and away from walls, structures, and other heat sources isn’t a preference — it’s a requirement.
Skipping water treatment. Untreated cooling tower water develops scaling, corrosion, and biological growth — including Legionella. Not optional. Water treatment needs to be planned and running from day one of operation, not added later when something starts going wrong.
Inadequate system integration. A hire cooling tower that isn’t properly matched to existing pipework, pumps, and controls can cause flow problems, pressure issues, and unreliable operation. Sort out the integration side before delivery. Not after the unit is already sitting on-site.
Key Considerations Before Installation
Capacity and Heat Load
The focus should be on heat rejection capacity — not water volume alone. An undersized system leads to overheating. An oversized unit wastes energy and cost. Give your supplier three things: heat load requirement, flow rate, and the temperature range and approach your process needs. Those three inputs drive the sizing conversation more than anything else.
Installation Requirements
Temporary cooling towers need more planning than people often expect. Four things to sort out before delivery:
- Space for airflow and drift control — drift from a poorly positioned tower can become a compliance issue in some environments
- Structural load capacity at the placement location
- Water supply and discharge connections
- Piping and pump integration matched to the existing system
None of these are complicated. Leaving them until the unit arrives though — that creates delays that a fifteen-minute planning conversation upfront would have prevented entirely.
Cooling Tower Hire: Maintenance and Support
A hire cooling tower running around the clock on a critical application needs a support structure behind it. Three questions worth asking your provider before committing to a hire arrangement:
- Is maintenance included in the package?
- How quickly can a technician be on-site if something goes wrong?
- Is monitoring available so performance issues get picked up before they become failures?
The answers to those three questions tell you a lot about what the hire relationship actually looks like once the unit is on-site and running.
Cooling Tower Hire: Energy Efficiency Factors
A cooling tower’s efficiency in operation comes down to a few factors. Correct sizing for the actual load. Adequate airflow and fan performance. Approach temperature optimised for the application. Clean, well-maintained fill media. And proper integration with the chiller system so condenser water temperatures stay stable rather than hunting up and down with every change in ambient conditions.
Get those things right from the start and the unit runs well. Let any one of them slide and efficiency drops faster than most people expect.
Cooling Tower Hire: Flexibility and Scalability
Cooling loads change. A hire arrangement sized for a two-week shutdown may need to extend. A system that handles normal load fine may fall short when ambient temperatures climb. Two questions worth raising with your supplier upfront rather than mid-hire:
- Can the system be scaled up or down if the situation changes?
- Are modular or additional temporary units available if demand increases?
Asking those questions at the start costs nothing. Finding out the answer when you actually need more capacity mid-hire costs time and money — usually both at the same time.
FAQs
Why does a water-cooled chiller need a cooling tower?
Think of it as a chain. The chiller absorbs heat from the chilled water loop and transfers it into the condenser water. That condenser water then needs somewhere to go. The cooling tower is where it goes — it takes that heat and pushes it out into the atmosphere through evaporation. Break that chain anywhere and the whole system suffers. Without a working tower, condenser water temperatures build, the chiller’s efficiency falls, and eventually the unit trips on a high-pressure fault. The two pieces of equipment aren’t optional extras for each other. They’re dependent.
When does hiring a cooling tower make more sense than buying one?
For planned shutdowns, emergency situations, and seasonal peak demand periods, hiring avoids the upfront capital cost, ongoing maintenance liability, and the storage problem that comes with ownership. You get the right unit for the specific situation and return it when the need passes.
How quickly can a temporary cooling tower be deployed?
Deployment speed varies. Site conditions, access constraints, and stock availability all play into how fast a unit can be on-site and running. For most metro locations — Sydney, Melbourne, Brisbane, and Perth — 24-48 hours from confirmed order is the standard for most urgent requests. What makes that timeline achievable is having site access, connection details, and power information confirmed before the call ends. Missing any of those details adds rounds of back-and-forth that push the timeline out.
What affects cooling tower performance?
Ambient wet-bulb temperature is the biggest variable — it sets the ceiling on how much heat the tower can reject. Water flow rate, airflow volume and quality, fill media condition, system design, and how well maintenance is carried out all play into how the unit performs in practice.
How do I work out the right size?
Start with heat load, water flow rate, and the temperature range your system requires. Give those figures to the supplier along with the site’s ambient wet-bulb conditions and the right unit can be sized from there. Guessing at capacity without those inputs usually leads to an undersized or oversized system — both of which create problems, just different ones.
Does a cooling tower need water treatment?
Yes, without exception. Scaling, corrosion, and biological growth — including Legionella — all develop in untreated cooling tower water. Water treatment needs to be planned and running from the first day of operation. Adding it later, when problems have already started appearing, is much harder to manage.
Ready to Talk Through Your Requirements?
For cooling tower hire across Sydney, Melbourne, Brisbane, and Perth — same-day and next-day deployment available for genuine emergencies.
Explore our cooling tower hire range or call 1800 626 996 — available 24/7.