How to Respond to a Hot Spot in Your Data Center
What is the best way to respond to a hotspot?
Chances are you have felt warmer temperatures while walking the cold aisle, or had to respond to a customer complaint, or worse had to respond to equipment failures because of high temperatures.
It is tempting to dial down the CRAH units and call it a day. However, that will not eliminate the root cause of the problem.
At Purkay Labs, we create a simple way to eliminate your hot spots and manage your airflow.
Let us take the case of our client who felt a hot spot in one of their Colocation facilities, despite the BMS reporting normal conditions. They used the AUDIT-BUDDY™ portable monitoring system to identify the problem (a BMS sensor failure) and return the room to ideal operating conditions.
Case Study: Using AUDIT-BUDDY Data to Resolve BMS/Hot Spot Issue
Figure 1: AUDIT-BUDDY QuickScan Mode & Static Heat Map
In the Fall, a technician servicing the IT equipment in a Colocation space reported high temperatures in the hot and cold aisles despite the Building Management System (BMS) reporting acceptable room temperatures. The Client needed to investigate the discrepancy between what the technician felt and what the BMS recorded. The Client rented two AUDIT-BUDDY systems to independently verify the room temperature.
The room in question is a contained space with 20 cabinets with 5kW load each (100kW Total IT load). Cold air is supplied via the ceiling from three roof mounted units (N+1) and return ducts in the hot aisle. A ceiling partition separated the hot and cold aisles, and blanking plates were installed on every rack to prevent air mixing. Power is fed from the A & B busway overhead in the hot aisle. The BMS room sensors were placed on the cold aisle wall about 48” from the front of the racks.
First, the Client used the AUDIT-BUDDY to take 1-minute readings across 20 racks in the hot and cold aisle. The live reporting showed (Figure 2: AUDIT-MATE Dashboard - only 10 rack data shown for easy viewing) that 8 racks had inlet temperatures above the SLA limit of 80.6°F / 27 °C. This confirmed that the BMS reports were incorrect. (Please note that AUDIT-BUDDY collects both °F and °C data).
Figure 2: AUDIT-MATE QuickScan Dashboard
The Colocation Provider launched an investigation. First, they checked the HVAC set points but found no anomalies. Then, they checked the BMS and found that an offset value for the deployed sensor was incorrect. This caused the reported temperatures to be different from the actual temperature of the air delivered to the room, causing the server inlet temperatures to reach critical levels.
After the Colocation Provider corrected the offset values, the Client placed AUDIT-BUDDY next to the BMS sensors to confirm the reported temperatures were now correct. The Client collected information for 1 hour, as seen in Figure 3 below.
Figure 3: AUDIT-BUDDY, BMS Sensor and Time-Trend Graph
Once the room stabilized, the Client repeated the initial 1 minute per rack data collection and found that the hot spots had been eliminated. The two before and after Static Heat Maps (Figure 4 and Figure 5) show a drastic reduction in room temperatures. The change in temperature allowed the Client and the Provider to avoid the risk of equipment failure and downtime.
Figure 4: Cold Aisle Environment - Before
Figure 5: Cold Aisle Environment - After
When the Client presented the case to senior management, sharing the Static Heat Maps, and actions taken by the service provider due to irrefutable data, a decision was made to purchase an AUDIT-BUDDY system and use the tool to benchmark the Colocation facilities hosting their IT equipment.
Key Takeaways
- Use the AUDIT-BUDDY system to collect independent data to eliminate hot spots or overcooling.
- The AUDIT-MATE program allows you to benchmark before & after projects.
- There is no installation required - simply collect data and remove from the site.
- Even if there is continuous monitoring, use AUDIT-BUDDY to periodically check that permanent monitoring equipment (BMS sensors, wireless sensors) are working correctly.
About AUDIT-BUDDY™
The AUDIT-BUDDY system is a portable temperature and humidity monitor that collects real-time and long-term data in any mission critical environment. AUDIT-BUDDY™ measures temperature and humidity variations independently at three different heights to provide insight on the air profile of your white space. Each system consists of three TH1 modules and an adjustable carbon fiber rod. Powered by AA alkaline batteries, AUDIT-BUDDY takes minutes to install and provides quick and accurate data.
To learn more, please visit www.purkaylabs.com or email info@purkaylabs.com