Author: Alex, IAQ & Health Specialist
Lead Designer: Wayne Luo, Cleanroom HVAC Engineer
Approved by: Danny Chen, Building Air Quality Team Leader, Holtop
Date: June 09, 2026
Precision motors will go down when humidity fluctuates.
When a global manufacturer of direct-drive motors in Singapore needed to upgrade their electronics cleanroom, they hit a thermodynamic wall. They required strict, flatlined environmental control in a climate that averages 90% humidity. Worse, it was a retrofit project. The existing mechanical room was too cramped to fit standard commercial Air Handling Units (AHUs).
You cannot just scale down an AHU. If you shrink the box, you choke the static pressure and kill the cooling capacity.
Here is the exact engineering framework we used to solve it.
1. Custom Modular DX Array
Standard boxes wouldn’t fit. We discarded off-the-shelf options and engineered a custom Direct Expansion (DX) system using 6 specialized Purification AHUs paired with 12 outdoor condensing units. By reorganizing the internal functional sections, we compressed the footprint to fit the tight retrofit space—without sacrificing a single kilowatt of cooling power.
2. Frameless, Zero-Leak Casings
A cleanroom is compromised before the air even hits the HEPA filter if your AHU casing leaks or traps dirt in the seams. We threw out standard aluminum-framed panels. We deployed the Airwoods 50W-Series: frameless, concealed-reinforcement casings with perfectly smooth interiors. No dead corners for bacterial growth. It strictly meets European EN1886 and German VDI 6022-1 hygiene standards.
3. PLC-Driven Latent Heat Control
To beat Singapore’s extreme equatorial latent heat, we utilized staged heat exchange technology driven by a centralized PLC. The smart algorithm dynamically adjusts the compressor output to match the live indoor load. The result is 24/7 flatlined temperature and humidity. No short-cycling, no frozen coils.
4. On-Site Commissioning
Shipping metal boxes is not an engineering solution. We dispatched our Holtop commissioning engineers directly to the Singapore site. We oversaw the physical installation, linked the systems, and tuned every PLC parameter until the cleanroom passed strict operational validation.
Post time: Jun-09-2026
