The data center has been in operation for about 1 year and 2 months. The dust levels in the computer room are relatively high. What is the most likely root cause?

In a relatively new data center (1 year and 2 months old), a common and significant source of particulate contamination is the concrete subfloor beneath the raised floor system. If this subfloor was not properly sealed during construction, the constant high-velocity airflow from cooling units in the underfloor plenum can cause the concrete to shed fine dust particles ("concrete dusting"). Poorly fitted floorboards create gaps and leak paths. The positive pressure within the plenum, designed to push cold air up through perforated tiles, will forcefully drive this dust-laden air through these gaps and into the computer room, leading to high dust levels.

A. The cleaning crew is not doing their work properly This is an operational issue, not a root cause. While poor cleaning exacerbates the problem, it cannot account for a continuous and high influx of new dust particles.
B. Every computer room has high dust levels due to constant high-speed air movement This is a false premise. Data centers are designed as clean environments, and their HVAC systems use high-efficiency filters (e.g., MERV 13 or higher) to remove particulates from the air.
C. Low pressure in the computer room While low (negative) pressure is a serious issue that pulls in contaminants from adjacent areas, dust from an unsealed subfloor (a massive surface area) driven by high plenum pressure often represents a more severe and direct contamination source.

1. Telecommunications Industry Association (TIA). (2017). TIA-942-B: Telecommunications Infrastructure Standard for Data Centers.

Section 6.3.3.2, Floor systems: "The structural floor slab beneath a raised floor should be sealed to reduce dust." This highlights that the subfloor is a recognized source of dust that requires mitigation (sealing). Poorly fitted floorboards would negate the benefits of a sealed room by providing a pathway for this dust.

2. ASHRAE. (2021). ASHRAE Datacom Series 14: Particulate and Gaseous Contamination in Datacom Environments (2nd Ed.).

Chapter 2, Sources of Particulate Contamination: This chapter identifies "Concrete and cement particles from floors, walls, and ceilings" as a primary internally generated contaminant. It further explains that the raised-floor plenum can be a reservoir for these particles, which are then distributed by the cooling system.

3. Uptime Institute. (2013). Data Center Site Cleaning: A Best Practices Guide.

Section: Sources of Contamination (p. 4): The guide explicitly mentions "Concrete Dusting" as a major source of contamination, stating, "Unsealed concrete subfloors will continuously shed dust into the subfloor plenum. The air-handling system will then distribute this dust throughout the data center." This directly links the subfloor dust to distribution via the plenum, for which poorly fitted floorboards (D) are a primary leakage path.