While great attention is devoted to industrial air conditioning and maintaining correct environmental conditions of a data center, regulating humidity in a server room is also vital for system performance and integrity. Humidity, the concentration of water in the air, is a variable with undesirable consequences for a data center at either extreme.
According to MovinCool, too much humidity in a server room can result in condensation and eventually corrosion or electrical shorts. Conversely, too little humidity contributes to electrostatic discharge. Static electricity in a server room is highly detrimental: electronics are sensitive to static shock and might be damaged beyond repair by the discharge.
To regulate humidity, data centers employ a combination of a computer room air conditioner, environmental sensors, and dehumidifiers or, alternatively, free cooling venting techniques that use the ambient outside air. For most server rooms, the challenge is setting the right temperature and humidity range to make the most use of free cooling, while still adequately protecting equipment from heat and condensation.
Data center cooling employing a dehumidifier is a relatively closed system, adding or removing water from the room as needed. If the server room instead leverages free cooling, venting in outside air, natural changes in temperature and humidity complicate the environment, making humidifying equipment work harder, especially on exceptionally wet, rainy days or very dry days. Free cooling’s cost savings using ambient air conditions are attractive, then, but the added complexity of maintaining a controlled computer center environment should not be discounted.