Crossflow gravity distribution delivers 53–56 dBA at source, meeting QCVN 26:2025's night-time boundary limit of 45 dBA. Head loss of just 4–6 kPa cuts circulation pump electricity costs. An open top basin means your team can clean and inspect while the tower keeps running — no production shutdown required.
Three problems draining your profits at the same time
When your plant is near a residential area, your production line runs 24 hours, and circulation pump costs keep climbing — these three pressures tend to arrive together.
Vietnam's QCVN 26:2025 sets the industrial zone night-time boundary limit at 45 dBA, with fines up to VND 160 million for violations. Effective November 2025. Standard counterflow towers produce 60–65 dBA at source — even with distance attenuation, night-time readings at the boundary can still exceed the limit.
Counterflow towers impose 40–55 kPa of head loss on circulation pumps. At 8,000 operating hours per year, a 500 m³/h counterflow system consumes approximately 12,000–18,000 extra kWh annually just to overcome this resistance. The LHR's crossflow gravity distribution cuts head loss to 4–6 kPa.
Counterflow tower nozzles and fill media sit inside a sealed casing. Cleaning requires a full shutdown and entry. For food, beverage, and pharmaceutical plants running around the clock, every maintenance shutdown translates directly into lost output. The LHR's open top basin lets maintenance staff access the distribution system from above while the tower keeps running.
Three engineering solutions, built into the structure
The LHR uses a crossflow configuration: water falls by gravity from a top-mounted open basin, distributed evenly across the fill media through calibrated holes — no high-pressure nozzles required. Without nozzle spray noise or water-impact turbulence, source noise is 6–10 dBA lower than a comparable counterflow tower.
In practice: 53–56 dBA at source, attenuating to below 45 dBA at the factory boundary under standard conditions, meeting QCVN 26:2025's night-time industrial zone limit. The LHR-U ultra-low-noise variant reduces this by a further 2–3 dBA for sites closer to residential buildings.
The physics of crossflow gravity distribution inherently produce very low head loss: just 4–6 kPa. By contrast, counterflow towers must pump water up to top-mounted nozzles, imposing 40–55 kPa of resistance that the circulation pump must continuously overcome.
For your plant: existing pumps typically need no replacement, saving retrofit costs. For an LHR-500L running 8,000 hours per year at Vietnam's industrial electricity tariff, annual savings are approximately 12,000–18,000 kWh, equivalent to VND 30–45 million.
The LHR's water distribution system sits at the top of the tower in an open gravity basin. Maintenance staff reach it via an external ladder and can clean the basin, clear distribution holes, and inspect fill media while the tower operates at full capacity — no shutdown needed.
For 24-hour continuous production lines: maintenance schedules are no longer constrained by shutdown windows; higher maintenance frequency keeps equipment in better condition; and production losses from maintenance shutdowns become a thing of the past.
Match your flow rate or noise requirement to the right model
Standard design conditions: inlet 37 °C, outlet 32 °C, wet-bulb 27 °C, atmospheric pressure 99.4 kPa.
| Model | Flow (m³/h) | Footprint L×W (mm) | Height (mm) | Fan Dia. (mm) | Motor (kW) | Dry Weight (kg) | Inlet/Outlet DN |
|---|---|---|---|---|---|---|---|
| LHR-100L | 100 | 2,250×2,250 | 3,200 | 1,800 | 2.2 | 980 | 125 |
| LHR-125L | 125 | 2,500×2,500 | 3,200 | 2,100 | 3.0 | 1,150 | 150 |
| LHR-150L | 150 | 2,750×2,750 | 3,400 | 2,100 | 4.0 | 1,320 | 150 |
| LHR-175L | 175 | 3,000×3,000 | 3,400 | 2,100 | 5.5 | 1,500 | 150 |
| LHR-200L | 200 | 3,250×3,250 | 3,400 | 2,400 | 5.5 | 1,680 | 200 |
| LHR-250L | 250 | 3,500×3,500 | 3,600 | 2,850 | 7.5 | 2,050 | 200 |
| LHR-300L | 300 | 3,750×3,750 | 3,800 | 3,200 | 11.0 | 2,480 | 250 |
| LHR-350L | 350 | 4,000×4,000 | 3,800 | 3,200 | 11.0 | 2,820 | 250 |
| LHR-400L | 400 | 4,500×4,500 | 4,000 | 3,200 | 15.0 | 3,350 | 250 |
| LHR-450L | 450 | 4,800×4,800 | 4,000 | 3,200 | 15.0 | 3,640 | 300 |
| LHR-500L | 500 | 5,000×5,000 | 4,200 | 3,700 | 15.0 | 3,980 | 300 |
| LHR-600L | 600 | 5,250×5,250 | 4,500 | 3,700 | 18.0 | 4,520 | 350 |
| LHR-700L | 700 | 5,500×5,500 | 4,500 | 4,050 | 18.5 | 5,280 | 350 |
| LHR-800L | 800 | 6,000×6,000 | 4,700 | 4,250 | 22.0 | 6,150 | 400 |
| LHR-900L | 900 | 6,500×6,500 | 4,700 | 4,550 | 22.0 | 7,020 | 400 |
| LHR-1000L | 1,000 | 7,000×7,000 | 4,900 | 4,550 | 30.0 | 7,980 | 400 |
LHR-U Ultra-Low Noise Variant — For Sites Near Residential Areas
A silencing section (approximately 700 mm additional height) reduces noise by a further 2–3 dBA. Recommended when the factory is within 50 m of residential buildings, or where the 40 dBA special zone limit applies under QCVN 26:2025. Available across the full model range.
Enquire about LHR-UConfirm these five conditions before submitting your enquiry to avoid discovering installation constraints after the model is selected.
Confirm the applicable QCVN 26:2025 limit for your zone (industrial: 45 dBA / special: 40 dBA) and the distance from the cooling tower to the nearest residential building, to determine whether standard LHR or LHR-U is required.
Available installation area must be ≥ tower footprint plus at least 600 mm service clearance on all sides. The LHR is 800–1,200 mm shorter than an equivalent counterflow tower, making it better suited to height-restricted locations.
LHR head loss is only 4–6 kPa, so existing pumps typically need no replacement. Confirm your existing pump's rated head and flow to verify system compatibility.
Confirm circulating water hardness, pH, and suspended solids are within normal ranges. Poor water quality accelerates fill media degradation.
Confirm the outlet temperature your process requires. LHR standard design: outlet 32°C at wet-bulb 27°C, approach temperature approximately 5–7°C. If your process requires an approach temperature ≤ 3°C, the LHN counterflow series is recommended.
We would rather you choose the right product than the wrong one. If your primary requirement falls into one of these categories, please review the alternative series first.
The LHN occupies a smaller footprint for the same flow rate. If installation area is the primary constraint, LHN is the better choice.
Learn about LHN →Hydraulic turbine drives the fan — no motor, no electrical equipment. Ideal for ATEX zones or facilities targeting zero cooling system electricity consumption.
Learn about LHRD →Process water circulates in sealed coils with no air contact — ideal for processes with strict water purity requirements.
Learn about AWA →Bolt pattern matches existing foundations; flanges align with existing pipework. Production resumes in 24–48 hours with no civil works required.
Learn about LH →53–56 dBA at source (1 m from the unit). The LHR-U ultra-low-noise variant adds a silencing section and reduces this by a further 2–3 dBA, meeting QCVN 26:2025's night-time 45 dBA industrial zone boundary limit.
In most cases, yes. The LHR's head loss is far below that of counterflow towers, and existing pumps typically have sufficient margin. COOLTEK engineers can verify compatibility based on your pump model and pipework parameters.
The open top gravity basin is reached via an external ladder on the tower body. While the tower runs at full capacity, maintenance staff enter from above to clean basin scale, clear distribution holes, and inspect fill media. A standard cleaning typically takes 2–4 hours.
Key factors: distance to the nearest residential building and the applicable noise limit. Distance > 100 m — standard LHR typically meets the 45 dBA limit; 50–100 m — LHR-U recommended; < 50 m or where the 40 dBA special zone limit applies — LHR-U required.
Standard design: inlet 37°C, outlet 32°C, wet-bulb 27°C, approach temperature approximately 5–7°C. Outlet temperature stability is slightly lower than counterflow towers. If your process requires an approach temperature ≤ 3°C, please review the LHN Series.
Yes. The LHR is 800–1,200 mm shorter than an equivalent counterflow tower, placing lower demands on rooftop clearance. Confirm rooftop load capacity and clearance height before ordering — COOLTEK's engineering team will verify against your structural parameters.
If your plant faces noise violations, rising pump electricity costs, and maintenance shutdowns, the LHR Series Cooling Tower is the solution to evaluate first.
53–56 dBA at source meets the QCVN 26:2025 night-time 45 dBA industrial zone boundary limit. LHR-U further meets the 40 dBA special zone limit, permanently removing the risk of noise violations.
Head loss of just 4–6 kPa — 90% lower than counterflow towers. Existing pumps require no replacement. Annual electricity savings of tens of millions of VND, with a typical payback period of 2–3 years.
Open top basin, accessible during operation. Maintenance schedules are no longer tied to shutdown windows. Higher maintenance frequency, better equipment condition, zero production losses from maintenance.
Fibreglass-reinforced plastic (FRP) resists corrosion and UV degradation. Low maintenance frequency combined with low energy consumption delivers significantly lower total lifecycle costs than traditional metal towers.
Selection Guide
For offices, hotels, and hospitals, noise compliance is the primary constraint — flow rate and efficiency come second.
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Technical Principles
Noise, head loss, outlet temperature stability, maintenance access — each type has its strengths.
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Energy Analysis
Real numbers: what does reducing head loss from 50 kPa to 5 kPa actually mean for a 500 m³/h cooling system?
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Regulatory Compliance
Effective November 2025, night-time 45 dBA hard limit, fines up to VND 160 million.
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Operations & Maintenance
How the crossflow top-access design frees maintenance from shutdown windows entirely.
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Cost Analysis
Circulation pumps are one of the largest electricity consumers. Reducing head loss is the most direct path to lower operating costs.
Read more →Submit your flow rate, boundary distance, and noise limit requirements. COOLTEK's engineers will provide an LHR or LHR-U model recommendation and technical proposal based on your actual site conditions.
