Cooling Tower Selection FAQ

The LH series' core value is drop-in replacement: if your facility already has a round cooling tower with unchanged piping positions and foundation dimensions, LH installs directly in place with no civil works required. Cooling capacity covers 10–200 m³/h, suitable for small-to-medium industrial facilities. The FRP shell requires no anti-corrosion maintenance in Vietnam's coastal salt-spray environment, with a service life of 15+ years.

LH series noise is approximately 52–58 dBA, higher than the LHR series (45–52 dBA). If your factory is close to residential areas, or local environmental authorities enforce strict nighttime noise limits (QCVN 26:2025 nighttime limit: 45 dBA), the LHR series is recommended. LH is better suited for industrial park interiors with sufficient separation distance from residential zones.

The largest LH model is LH-200 (200 m³/h). Multiple units can be paralleled beyond this range, but when single-unit demand exceeds 200 m³/h, square towers (LHR or LHN) offer better footprint efficiency. For projects in the 200–500 m³/h range, LHR is the more economical single-unit solution.

LH series inlet/outlet flange positions are consistent with mainstream round tower standards. In most replacement scenarios, after removing the old tower, LH installs directly in position without modifying piping routes or foundation structures. Switching to a square tower typically requires rerouting piping and rebuilding foundations — higher civil costs and longer downtime.

FRP (Fiber Reinforced Plastic) has inherent resistance to salt spray, acid rain, and industrial exhaust — no anti-rust coating maintenance required. In Vietnam's coastal industrial zones (Hai Phong, Ho Chi Minh City area), normal service life is 15–20 years. Galvanized steel shells in the same environment typically begin showing corrosion within 5–8 years and require periodic repainting.

Do not choose LH in these scenarios: ① Strict noise limits (nighttime ≤45 dBA) — choose LHR; ② Single-unit demand over 200 m³/h — choose LHR or LHN; ③ Process water must be isolated from outside air — choose AWA; ④ Explosion-proof zone (Zone 1/2) — choose LHRD; ⑤ Extremely limited rooftop space — square towers have better footprint efficiency.

Confirm: ① Design circulating water flow rate (m³/h); ② Inlet and outlet water temperatures (°C); ③ Local wet-bulb temperature (Vietnam north summer: ~28–29°C, south: ~27–28°C); ④ Old tower outer diameter and inlet/outlet flange dimensions (to confirm direct drop-in fit); ⑤ Whether the installation location has noise restrictions.

LHR is the lowest-noise open tower in COOLTEK's five series, suitable for three scenarios: ① Factories near residential areas where nighttime noise must meet QCVN 26:2025 limits (45 dBA); ② Commercial buildings, hospitals, schools, and other noise-sensitive facilities requiring cooling systems; ③ Medium-to-large industrial projects with cooling capacity needs of 50–1500 m³/h. The crossflow structure's pump head loss is 4–6 kPa lower than counterflow towers — in Vietnam's EVN electricity pricing environment, this pump energy saving continuously converts to operational cost advantage.

Yes. LHR series noise at three measurement points (1m, 3m, 5m from the tower) is 52 dBA, 47 dBA, and 45 dBA respectively, meeting Vietnam's QCVN 26:2025 commercial zone nighttime noise standards. Commercial buildings typically install on rooftops; LHR's crossflow structure allows maintenance without shutdown, with side access panels enabling fill inspection during operation — ideal for 24-hour facilities.

It is the most suitable open tower in COOLTEK's five series for this scenario. LHR's noise design baseline is QCVN 26:2025 nighttime industrial zone limit (45 dBA), measured at 45 dBA at 5m from the tower. If your factory is more than 20m from the nearest residence, LHR can typically meet compliance requirements. For distances under 20m, provide the specific distance and our engineers can calculate the sound attenuation compliance margin.

In crossflow structure, water enters the fill from the side perpendicular to airflow, with lower water distribution height than counterflow towers, resulting in less water droplet impact noise. Additionally, LHR's fan is mounted on top with upward exhaust, creating a shorter noise propagation path to surroundings compared to counterflow towers. At equivalent cooling capacity, LHR is approximately 3–5 dBA quieter than LHN.

Crossflow water distribution relies on gravity — water flows naturally down from the top distribution trough without overcoming the reverse resistance of the fill layer. Counterflow towers require water to spray upward through the fill, generating 4–6 kPa of additional resistance. At EVN electricity price of 2,204 VND/kWh, each 1 kPa reduction in pump head loss saves approximately 800–1,200 kWh of pump energy per year for a 500 m³/h system.

There is one decision rule: noise priority → LHR; space priority → LHN. LHR's crossflow structure occupies approximately 15–20% more space than LHN's counterflow structure, but is 3–5 dBA quieter. If the installation location is near residential or noise-sensitive areas, LHR is the first choice. If rooftop area is constrained, LHN has better footprint efficiency (23.8% less space for the same cooling capacity). Neither is superior — only different constraint conditions.

① Extremely limited rooftop area — LHR occupies more space than LHN, choose LHN; ② Explosion-proof zone (Zone 1/2) — LHR lacks explosion-proof certification, choose LHRD; ③ Process water must be completely isolated from outside air (semiconductor, induction furnace) — LHR is an open tower, choose AWA; ④ Lower approach temperature required (≤3°C) — LHN's counterflow structure has higher thermal efficiency.

LHN is the highest footprint-efficiency open tower in the five series, with the core advantage of 23.8% smaller footprint for the same cooling capacity. Suitable for two scenarios: ① Rooftop space-constrained projects that cannot accommodate crossflow towers; ② High-precision cooling scenarios requiring lower approach temperature (≤3°C), such as precision machine tools and data center auxiliary cooling. Cooling capacity covers 100–2000 m³/h, suitable for medium-to-large industrial projects.

Yes. LHN's compact counterflow structure is particularly suited for rooftop installation. Compared to crossflow towers, LHN occupies approximately 23.8% less space for the same cooling capacity, saving valuable space on constrained rooftops. Note that LHN uses a single central inlet pipe — the pump must provide sufficient head (typically 4–6 kPa more than crossflow towers). Confirm the pump operating point before installation.

In counterflow structure, water flows downward while airflow moves upward — opposing directions create the maximum temperature gradient in the fill layer, achieving the highest heat transfer efficiency. This allows LHN's approach temperature (outlet water temperature minus wet-bulb temperature) to reach ≤3°C, while crossflow towers typically achieve 4–5°C. For processes requiring precise cooling water temperature control, this 1–2°C difference can directly affect product quality.

LHN noise is approximately 48–55 dBA, about 3 dBA higher than LHR (45–52 dBA). Within industrial zones (QCVN 26:2025 daytime limit 70 dBA, nighttime 55 dBA), LHN can typically meet compliance requirements. However, if the factory is immediately adjacent to residential areas with nighttime limits tightened to 45 dBA, LHN may not comply — choose LHR in that case.

① Strict noise requirements (nighttime ≤45 dBA) — choose LHR; ② Explosion-proof zone (Zone 1/2) — choose LHRD; ③ Process water must be isolated from outside air — choose AWA; ④ Pump head insufficient to overcome counterflow tower's additional head loss (4–6 kPa) — evaluate pump operating point first.

LHRD simultaneously addresses two challenges: explosion-proof compliance and zero fan power consumption. Suitable for chemical plants, petrochemical facilities, paint and solvent production in Zone 1/2 explosion-proof areas, as well as factories with high electricity costs or energy reduction goals. The hydraulic turbine uses residual pressure from the circulating water system to drive the fan — no motor required — fundamentally eliminating electrical ignition risk in explosion-proof zones.

Yes. The core requirement of Zone 1/2 explosion-proof certification is eliminating ignition sources. LHRD's hydraulic turbine drive uses no motor whatsoever, physically eliminating electrical ignition risk — a more thorough approach than explosion-proof motor solutions. LHRD has passed Zone 1/2 certification under ATEX/IECEx standards and can be directly used in certification body compliance reviews.

No physics violation. LHRD's energy source is the residual pressure in the circulating water system — pump head remaining after overcoming pipe resistance, with 36–54 kPa unused. LHRD's turbine converts this residual pressure into mechanical energy to rotate the fan. Fan power consumption is genuinely 0 kW, but the pump must provide this additional 36–54 kPa of pressure. If your pump head is already sufficient, this energy is free; if pump upgrade is needed, a full lifecycle cost analysis is required.

LHRD initial investment is typically 15–25% higher than explosion-proof motor solutions, primarily due to turbine components. However, LHRD has no motor, no motor maintenance costs, and no electricity costs — total lifecycle cost (15 years) is typically lower than explosion-proof motor solutions. With EVN electricity prices continuing to rise, payback period is typically 3–5 years. Provide specific flow rate and local electricity price for a precise payback calculation.

① Pump head insufficient for 36 kPa residual pressure — turbine cannot operate normally, choose LHR or LHN with explosion-proof motor; ② Non-explosion-proof zone with cost-sensitive initial investment — standard LHR/LHN offers better value; ③ Process water must be isolated from outside air — LHRD is an open tower, choose AWA.

AWA's core function is 100% physical isolation of process water, suitable for: ① Production equipment OEM manuals requiring cooling water conductivity below 50 μS/cm (induction furnaces, semiconductor equipment, laser cutting machines); ② GMP production lines where cooling water systems cannot allow microbial contamination; ③ Precision injection molding where cooling water scaling affects mold precision; ④ Specialty chemicals where process water contains corrosive ions that cannot be contaminated by external water quality.

Both isolate process water, but there are three key differences: ① Scaling risk: Plate heat exchanger channel spacing is 2–4mm; suspended solids and microorganisms in open tower circulating water easily scale here, requiring periodic cleaning. AWA's copper coil diameter is larger, with lower scaling risk. ② Footprint: AWA is an integrated unit, smaller than the combined "open tower + heat exchanger + connecting piping" solution. ③ Initial cost: AWA is typically higher than an equivalent open tower alone, but lower than "open tower + high-quality plate exchanger" combination.

The process water side (inside the coil) is a closed loop with no contact with outside air — water quality does not concentrate through evaporation, so continuous water treatment is generally not required. Initial fill with deionized or softened water is recommended, along with corrosion inhibitor. The external spray water (outside the coil) will evaporate and concentrate — recommend makeup water TDS below 500 ppm with automatic blowdown valve, maintaining concentration ratio at 3–4x.

AWA simultaneously runs fan and spray pump — total installed power is approximately 1.5–2x that of an equivalent open tower. This is the physical cost of water quality isolation. For facilities where core equipment value exceeds several million USD, this cost is typically justified — a single equipment shutdown due to water quality issues often exceeds AWA's additional electricity costs over many years. If your cooling requirement is extremely energy-sensitive, evaluate the full lifecycle cost comparison of "open tower + plate heat exchanger."

① Cooling requirement is standard industrial heat dissipation with no special water quality requirements — open tower offers better value; ② Single-unit demand exceeds 500 m³/h — AWA's largest model is AWA-N500; beyond this, multiple units in parallel are needed, consult engineers for feasibility assessment; ③ Extremely energy-sensitive with no special process water quality requirements — open tower + water softening treatment is a more economical solution.