Project Background
Henrico Tower is a 33-story commercial office building in Hanoi, Vietnam. The building's HVAC system requires rooftop cooling towers for the central chiller plant. Rooftop installations in urban high-rise buildings present unique challenges related to noise, space constraints, and structural loading.
Cooling Challenges
- Noise compliance in urban environment: Vietnam's QCVN 26:2025 noise standard sets strict limits for commercial buildings in urban areas. Rooftop cooling towers must meet these limits to avoid complaints from neighboring buildings and building occupants.
- Rooftop space constraints: The 33rd floor rooftop has limited available space, requiring a compact footprint while maintaining 900RT total capacity.
- Wind exposure at height: Rooftop installations at 33 floors are exposed to strong winds that can disrupt tower airflow patterns. The 45° air deflectors were specified to manage wind effects.
COOLTEK Solution
COOLTEK selected the LHN series crossflow square tower with custom 45° air deflectors:
- LHN crossflow design: The crossflow configuration uses gravity water distribution (no pressurized nozzles), significantly reducing operating noise compared to counterflow designs. This is critical for QCVN 26:2025 compliance in urban commercial buildings.
- 45° air deflectors: Custom-designed deflectors redirect strong rooftop winds away from the tower air intake, preventing airflow disruption and maintaining consistent cooling performance regardless of wind direction.
- Compact 3-unit configuration: Three LHN-300RT units provide 900RT total capacity in a compact footprint suitable for the rooftop space constraints.
Project Results
- QCVN 26:2025 noise compliance achieved — measured noise levels within limits for commercial urban buildings
- Stable cooling performance despite rooftop wind exposure, thanks to 45° air deflectors
- Compact rooftop installation within available space constraints on the 33rd floor
- Reliable HVAC support for the full building occupancy since commissioning
Frequently Asked Questions
Why is the LHN crossflow design quieter than counterflow for commercial buildings?
The LHN uses gravity water distribution troughs instead of pressurized spray nozzles. This eliminates the splashing noise from high-pressure water impact on fill media, reducing operating noise by 3–5 dB(A) compared to counterflow designs of equivalent capacity.
What is the purpose of the 45° air deflectors on rooftop installations?
At rooftop height, wind speeds are significantly higher than at ground level. Without deflectors, strong winds can create back-pressure on the air intake side of the tower, reducing airflow and cooling efficiency. The 45° deflectors redirect wind upward, protecting the intake while allowing free exhaust air discharge.
Have a commercial building or high-rise HVAC cooling requirement?
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