Cross-flow towers
Air moves horizontally across water falling through the fill. Hot water is distributed from open basins by gravity, which keeps pump head low and makes the distribution easy to inspect.
Ebara Shinwa & Mesan cooling towers
Cooling towers
Reliable heat rejection for water-cooled chillers and industrial processes. Ebara Shinwa and Mesan cooling towers, built to CTI standards and matched to your chiller plant.
- Cross-flow & counter-flow
- CTI standard
- Matched to the chillers
- Water-treatment guidance
The basics
What does a cooling tower do?
Every water-cooled chiller must get rid of the heat it removes from a building, plus the energy used by its compressor. A cooling tower does this by evaporation: warm condenser water is spread over fill packing while fans draw air through, and a small part of the water evaporates, cooling the rest.
Because it works by evaporation, a tower can cool water to within a few degrees of the outdoor wet-bulb temperature, well below the dry air temperature. That is why water-cooled plants are usually more efficient than air-cooled chillers, especially in hot, dry weather.
The tower works as one system with the chillers, pumps and water treatment. A tower that is undersized, dirty or poorly treated raises condenser temperatures and makes every chiller use more power.
- Typical cycles of concentration
- 2 – 4
- Make-up water saved
- 20%
- Blowdown saved
- 50%
- Built to
- CTI
Six or more is often possible with good water treatment
by raising cycles of concentration from 3 to 6
by raising cycles of concentration from 3 to 6
Cooling Technology Institute standards
How it works
How a tower cools water
Warm water in, cool water out. Here is what happens in between.
-
01
Hot water in
Warm water from the chiller condensers is pumped to the top of the tower and spread over the fill.
-
02
Fill and airflow
The fill breaks the water into thin films so it meets as much air as possible. Fans move air through the tower.
-
03
Evaporation
A small fraction of the water evaporates, carrying heat away with it. The rest falls into the basin, cooler than before.
-
04
Cool water back
Pumps return the cooled water to the condensers. Make-up water replaces what has evaporated, drifted away or been bled off.
Two numbers to know. The range is how much the tower cools the water (hot in minus cold out), and is set by the chiller load. The approach is how close the cold water gets to the outdoor wet-bulb temperature, and is set by the size of the tower.
Tower types
Cross-flow or counter-flow?
Both designs are proven. The choice depends on space, pumping, maintenance access and the duty.
Counter-flow towers
Air moves upwards against the falling water, which is sprayed from pressurised nozzles. The design is typically compact in plan area.
Ebara Shinwa towers
Japanese cooling towers from Ebara Shinwa, well suited to Ebara chiller plants.
Mesan towers
A further range of cooling tower sizes and configurations to suit each project.
Fans and drives
Variable-speed fan drives reduce energy use and noise whenever full cooling is not needed.
Drift eliminators
Eliminators catch water droplets before they leave the tower, reducing water loss and spray around the tower.
Is it right for you?
Where cooling towers fit
A strong fit when…
- You run water-cooled chillers: centrifugal, screw or absorption
- You need to cool industrial process water, for example for moulding machines, compressors or furnaces
- You want the lowest chiller energy use per ton of cooling
- Make-up water is available and can be treated
Consider air-cooled equipment when…
- Water is scarce, expensive or of very poor quality
- The plant is small and simplicity matters more than peak efficiency
- No one will be responsible for water treatment
Air-cooled options we supply:
What we supply
Towers matched to your chiller plant
Cooling towers manufactured to CTI standards, matched to chiller plants for reliable heat rejection. We select the towers together with the chillers and pumps, so condenser water flow, temperatures and approach are right for the whole plant.
Our cooling tower range
- Cross-flow & counter-flow designs
- Matched to chiller selection
- CTI standard
- Ebara Shinwa and Mesan cooling towers
- Supply, installation and commissioning with the chiller plant
Track record
Cooling tower projects
Projects on our list that include cooling towers, largest first.
2,500 TR
Hattar · Industrial & Pharma
Coronet Foods (Pvt) Ltd
Supply of HVAC Equipment
2,500 TR
1,800 TR
Peshawar · Commercial & Hospitality
Pearl Continental Hotel
Complete MEP Works
- Chillers
- Cooling towers
- AHUs
- FCUs
- BMS
- Electrical
- Fire fighting
1,200 TR
Karachi Region · Commercial & Hospitality
Metro Pakistan (Pvt) Ltd
Complete HVAC Works
- Chillers
- Cooling towers
- AHUs
- FCUs
- BMS
- MS piping & ducting
1,200 TR
Lahore · Commercial & Hospitality
Metro Pakistan (Pvt) Ltd
Complete HVAC Works
- Chillers
- Cooling towers
- AHUs
- FCUs
- BMS
- MS piping & ducting
1,200 TR
Planning a project
Keep your tower efficient and safe
Most of these recommendations follow US Department of Energy (FEMP) best practice for cooling tower management.
Size for local weather
Tower performance depends on the outdoor wet-bulb temperature. Humid coastal cities such as Karachi need more tower capacity than dry inland sites for the same duty.
Water treatment
Evaporation concentrates dissolved minerals in the tower water. Treatment and controlled blowdown prevent scale, corrosion and biological growth.
Automatic blowdown
Conductivity controllers bleed off water only when minerals reach a set level. Meters on the make-up and blowdown lines show how much water the tower really uses.
Save water
Many towers run at two to four cycles of concentration, and six or more is often possible. Going from three to six cycles cuts make-up water by 20% and blowdown by 50%.
Keep it clean and safe
Side-stream filtration removes silt, and basin covers reduce algae. A water management plan with regular disinfection and inspection controls bacteria such as Legionella.
Placement
Towers need free airflow. Placing them too close to walls or to each other lets warm, moist air recirculate and cuts capacity.
FAQ
Cooling towers: common questions
Can’t find your answer? Ask our engineers.
What does a cooling tower do?
It removes heat from the condenser water of chillers or industrial processes by evaporating a small part of the water into the air, which cools the rest so it can be reused.
What is the difference between cross-flow and counter-flow towers?
In a cross-flow tower air moves horizontally across the falling water, and hot water is distributed by gravity. In a counter-flow tower air moves upwards against the falling water, which is sprayed from pressurised nozzles. Both work well; the choice depends on space, pumping and maintenance access.
What are range and approach?
Range is the temperature drop of the water through the tower (hot water in minus cold water out). Approach is the difference between the cold water temperature and the outdoor wet-bulb temperature. The load sets the range; the size of the tower sets the approach.
Why does a cooling tower use water?
Water leaves in three ways: evaporation, which is how the tower cools; blowdown, water drained off to stop minerals building up; and drift, fine droplets carried out with the air. Make-up water replaces all three.
What are cycles of concentration?
The ratio of dissolved minerals in the tower water to those in the make-up water. Higher cycles mean less blowdown and less water use, but need good treatment to prevent scale. US DOE guidance notes many towers run at 2–4 cycles, and raising cycles from 3 to 6 cuts make-up water by 20%.
How is Legionella controlled in a cooling tower?
Through a water management plan: continuous treatment with biocides, keeping the tower and basin clean, avoiding stagnant water, effective drift eliminators and regular testing.
Does an absorption chiller need a bigger cooling tower?
Yes. An absorption chiller rejects about 1.75–2.4 kW of heat for every kW of cooling, compared with about 1.2 kW for an electric chiller, so its tower and condenser pumps are larger.
Do you supply towers with the chillers?
Yes. We select, supply and install cooling towers together with chillers, pumps and piping, and can replace towers on existing plants.
Get a selection
Is your tower holding the plant back?
Tell us your chiller capacity, condenser water flow and site location, or send photos of your existing towers. Our engineers will size the right cooling towers for your plant.