A data center hot spot refers to server input air conditions that are either too hot or too dry. The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) thermal guidelines state that the recommended temperature near the inlet of servers should range between 65°F to 80°F and the relative humidity should be between 40% and 60%. A hot spot occurs when the environment around the air input to the server or other equipment is higher in temperature or lower in moisture content than recommended in the ASHRAE guidelines.
In an ideal cooling system, all of the hot air in the data center rises, passes through the cooling system, and is then recirculated into the data center. However, a collection of hot air is inevitable and is often caused by excess cooling capacity. With an abundance of cooling units running simultaneously, there is often excess airflow in the data center, which ultimately turn into hot spots. Instead of cool air being pushed past the servers, the air is pushed up and away from the servers, causing the further accumulation of hot air.
How to Resolve Data Center Hot Spots
Hot spots can be damaging to a data center as they may result in reduced system reliability and increased downtime. Hot spots may also cause cooling systems to work harder to dissipate heat, consuming more energy and decreasing data center energy efficiency. Some methods to help prevent and resolve hot spots include:
- Introduce containment. Data center containment reduces bypass airflow by decreasing the amount of excess airflow in a space. Containment includes the placement of hot aisle and cold aisle cabinets that are positioned so the front of one cabinet never faces the back of another cabinet. This creates alternating rows of cold and hot air and blanking panels can be used to prevent hot air from entering the cold aisle.
- Share the cooling load. By spreading high-density servers, the cooling load will be shared evenly amongst all server locations. This will minimize the likelihood of hot spots within one particular location, and it will also ensure efficient cooling.
- Implement temperature monitoring. ASHRAE recommends placing no fewer than six temperature sensors in each rack, mounted at the top, middle, and bottom of both the front and back of the rack. Data center environment monitoring software will allow you to monitor, trend, and alert on temperature so you can identify hot spots before they cause harm.
- Manual check-ups. Without a monitoring solution, there should be frequent inspections throughout the data center to check for hot spots and to ensure the measures used to reduce hot spots are also working properly. For instance, the space beneath the data center floor tiles should be checked routinely to ensure efficient air distribution beneath the tiles.
- Effective air delivery. A quality commercial HVAC system is extremely important in terms of combatting hot spots. However, merely cooling the data center as a whole is not effective as the air that enters the intakes on the equipment will not be cold enough to prevent hot spots. Instead, the cold air should be directed towards strategic locations within the data center to ensure the intakes on the individual servers are getting the cold air they need.
Prevent Data Center Hot Spots with DCIM Software
Data Center Infrastructure Management (DCIM) software is very effective for identifying and preventing hot spots. It allows you to easily monitor the temperature within each cabinet and also features thermal time-lapse videos on your 3D floor map so you can visualize the formation of hot spots. By trending temperature over time, you can see if temperatures are rising and hot spots are likely to form and by setting thresholds and alerts on temperature, you can be automatically notified via email when temperatures exceed your thresholds.
Want to see how Sunbird’s world-leading DCIM solution makes it easy for you to visualize, prevent, and resolve hot spots? Get your free test drive now!
