Crossflow, Counterflow, Closed-Circuit, Water Turbine
— Your Engineering Constraint Determines Which Series Fits
When selecting a cooling tower, three dimensions determine the right solution: flow pattern (crossflow vs. counterflow), water quality requirement (open vs. closed circuit), and installation constraint (footprint / explosion-proof / drop-in). Each COOLTEK series addresses a distinct constraint. This page helps you narrow down in 60 seconds.
Each Series Solves One Specific Engineering Constraint
The five series are not ranked by quality — each has a unique physical advantage and a clear boundary where it is not the right fit.
Old round tower failed — piping and foundation are still good, just need a new tower without major rework
Round Drop-InRound casing, bolt-hole pattern, and inlet/outlet flange positions are physically compatible with legacy round towers. No piping or foundation changes needed. Flow range: 8–1,000 m³/h. Installation cost savings: 30–50%. Production typically resumes within 24–48 hours.
Physical trade-off: Higher noise level — not suitable for noise-sensitive sites.
Explore LH Series →Site is adjacent to residential areas or schools — nighttime noise limit of 45 dBA is a real compliance risk
Ultra-Quiet CrossflowGravity-fed crossflow distribution. Far-field noise at 16 m is 1.8–3.1 dB(A) lower than counterflow towers, meeting QCVN 26:2025 nighttime boundary limit of 45 dBA. Head loss only 4–6 kPa — significantly reduces pump energy cost. Open top basin allows cleaning during operation. Flow range: 100–1,000 m³/h.
Physical trade-off: Largest plan footprint; approach temperature slightly higher than counterflow.
Explore LHR Series →Installation footprint is fixed and limited — but the process demands tight outlet temperature control
Compact CounterflowSquare counterflow structure. Same flow capacity in ~24% less footprint than crossflow. 180° counterflow achieves the highest heat transfer efficiency, with approach temperature ≤3°C — meeting the stringent requirements of semiconductor and precision chemical processes. Flow range: 80–1,000 m³/h.
Physical trade-off: Tallest profile; head loss 40–55 kPa requires higher pump head.
Explore LHN Series →Chemical plant Zone 1/2 hazardous area — and rising EVN electricity tariffs make fan motor costs unsustainable
Water Turbine DrivenHydraulic turbine replaces the electric motor. System surplus head (≥36 kPa) drives the turbine to spin the fan — 0 kW fan operating power. No motor, no cables on the tower top — structurally eliminates electrical ignition sources and naturally exempts the unit from IECEx/TCVN 10888 certification. Flow range: 100–1,000 m³/h.
Physical trade-off: Requires system surplus head ≥36 kPa; fan speed varies with water pressure, so outlet temperature stability is slightly lower than motor-driven units.
Explore LHRD Series →Precision equipment (induction furnaces, semiconductor packaging) vulnerable to scale — acid-cleaning downtime is a major operational cost
Closed-Circuit IsolationProcess water circulates in a sealed stainless steel (or copper) coil, 100% physically isolated from ambient air. Without evaporative concentration, scale formation is eliminated at the source — zero scale, zero acid-cleaning downtime, zero chemical waste discharge. Suitable for induction furnaces, injection molding, semiconductor equipment, pharmaceutical reactors. Flow range: 6–500 m³/h.
Physical trade-off: Total installed power is approximately 1.5–2× that of an equivalent open-circuit tower; higher initial investment.
Explore AWA Series →Core Parameter Comparison: Crossflow, Counterflow, Closed-Circuit & Water Turbine
Each series has a unique physical advantage — and a clear physical trade-off. Use this table to complete your initial screening in one view.
| Parameter | LH Round Drop-In |
LHR Ultra-Quiet Crossflow |
LHN Compact Counterflow |
LHRD Water Turbine |
AWA Closed-Circuit |
|---|---|---|---|---|---|
| Form Factor | Round | Square | Square | Square | Square |
| Air-Water Contact | Vertical counterflow | Horizontal crossflow | Vertical counterflow | Horizontal crossflow | Sealed coil (closed) |
| Water Distribution | Rotating nozzle | Gravity basin | Fixed nozzle | Gravity basin | Closed coil |
| Flow Range | 8–1,000 m³/h | 100–1,000 m³/h | 80–1,000 m³/h | 100–1,000 m³/h | 6–500 m³/h |
| Head Loss | 40–55 kPa | 4–6 kPa | 40–55 kPa | Requires ≥36 kPa surplus | Process side independent |
| Noise Level | Standard counterflow | 53–56 dBA (at source) | Standard counterflow | Standard crossflow | Standard counterflow |
| Unique Advantage | Compatible with legacy round towers | Lowest noise, lowest head loss | Smallest footprint, tightest approach temp | 0 kW fan, no electrical components | Absolute process water isolation |
| Key Trade-Off | Higher noise | Largest plan footprint | Tallest; higher noise | Requires ≥36 kPa surplus head | Higher energy use; higher CAPEX |
| Typical Application | Drop-in replacement | Noise-sensitive sites | Space-constrained + precision temp | Hazardous area + energy saving | Precision equipment water quality |
Standard design conditions: inlet 37°C, outlet 32°C, wet-bulb 27°C, atmospheric pressure 99.4 kPa. All series use FRP casing rated for 1,000-hour salt spray with a design life of 15–20 years.
Send Project Parameters for Precise SelectionNot Sure Which Series? Three Questions to Narrow It Down
Answer these three questions in order. You will typically be able to eliminate three or four unsuitable series.
Does your cooling water need to be completely isolated from ambient air?
Are you replacing an existing round cooling tower?
What is your plant's primary engineering constraint?
Still unsure? Send your project parameters — a COOLTEK engineer will advise directly
Verifiable Technical Standards for COOLTEK Cooling Towers
No marketing language — only physical parameters and boundary conditions that can be verified on-site.
FRP Casing Durability
All series use FRP (fiberglass) casing rated for 1,000-hour salt spray with no damage. Design life: 15–20 years. Suitable for Vietnam's coastal high-humidity, high-salinity environment.
Standard Design Conditions
Inlet 37°C, outlet 32°C, wet-bulb 27°C, atmospheric pressure 99.4 kPa. All selections are based on these published conditions. Correction factors available for non-standard conditions.
Physical Trade-Offs Disclosed
LHR vs. LHN noise differential, LHRD surplus head threshold ≥36 kPa, AWA energy multiplier 1.5–2× — all boundary conditions are published on each product page.
Noise Measurement Data
LHR series noise data at 1 m, 5 m, and 16 m from the tower are published on the product page. These can be directly compared against QCVN 26:2025 boundary limits for verification.
LHRD Surplus Head Requirement
LHRD requires system surplus head ≥36 kPa. Below this threshold, fan speed is insufficient and cooling capacity decreases. Please provide system head data when enquiring.
AWA Coil Material Options
AWA standard coil is copper, suitable for most industrial cooling water. If process water contains corrosive ions (Cl− >200 ppm, pH <6 or >9), specify stainless steel 316L coil.
Most Frequently Asked Questions in Engineering Selection
These questions come from real enquiries. All answers are based on verifiable physical parameters.
What is the difference between crossflow and counterflow cooling towers?
In a crossflow cooling tower (e.g. LHR series), water flows horizontally through the fill media. Noise is lower (53–56 dBA at source) and head loss is only 4–6 kPa, making it ideal for noise-sensitive sites. In a counterflow cooling tower (e.g. LHN series), water falls from the top while air rises from the bottom, achieving higher heat transfer efficiency and approach temperature ≤3°C, with a smaller footprint — ideal for space-constrained sites with strict outlet temperature requirements.
Can I replace an old round cooling tower without changing the piping?
Yes. The COOLTEK LH series is designed for drop-in replacement. The round casing, bolt-hole pattern, and inlet/outlet flange positions are compatible with mainstream legacy round towers. No piping or foundation changes are needed. Flow range: 8–1,000 m³/h. Installation cost savings: 30–50% vs. full rebuild. Production can typically resume within 24–48 hours.
Which cooling tower is suitable for explosion-proof zones (Zone 1/2)?
The COOLTEK LHRD water turbine cooling tower. LHRD uses system surplus head (≥36 kPa) to drive a hydraulic turbine that spins the fan — no motor, no cables, no electrical components on the tower top. This structurally eliminates electrical ignition sources and naturally exempts the unit from IECEx/TCVN 10888 explosion-proof certification requirements.
How can a factory near residential areas meet Vietnam QCVN 26:2025 nighttime noise limits?
The COOLTEK LHR crossflow cooling tower measures 53–56 dBA at source. The LHR-U ultra-quiet variant reduces this by a further 2–3 dBA, meeting the QCVN 26:2025 nighttime boundary limit of 45 dBA. Gravity-fed crossflow distribution reduces noise at the source — more effective than adding noise barriers, without compromising cooling performance.
How does the AWA closed-circuit tower prevent scale buildup in precision equipment cooling water?
The COOLTEK AWA closed-circuit cooling tower eliminates scale from the root cause. Process water circulates in a sealed stainless steel (or copper) coil, completely isolated from ambient air and spray water. Without evaporative concentration, scale has no mechanism to form. Suitable for induction furnaces, injection molding machines, semiconductor equipment, and pharmaceutical reactors. Flow range: 6–500 m³/h.
What are the flow ranges for each of the five COOLTEK cooling tower series?
LH: 8–1,000 m³/h; LHR: 100–1,000 m³/h; LHN: 80–1,000 m³/h; LHRD: 100–1,000 m³/h (requires system surplus head ≥36 kPa); AWA: 6–500 m³/h. All series support parallel installation for higher flow requirements.
Tell Us Your Constraints — We'll Handle the Engineering Calculations
Simply provide your design flow rate, inlet/outlet temperature requirements, available footprint, and your primary constraint (noise / space / explosion-proof / water quality / drop-in replacement). A COOLTEK engineer will match you to the right series and prepare a technical proposal.