We know that every room, especially a server room, has its own microclimate. Even sensors that are inches apart can read different values! Although similar applications might share the same temperature threshold range, every sensor placement location is unique. It sounds strange that there would be such fluctuations in temperature within inches, but this happens because your server room has its own minature weather pattern!
So how do you figure out the correct temperature range for monitoring your server room or where to place your sensor? As many conditions as there are for the actual ourdoor weather patterns, there are many variables for sensor placement and operational range because of the changing indoor microclimate.
Essentially, in order to determine the right thresholds for your server room "environment", you need to acquire adequate baseline knowledge. This process is called "baselining", which involves monitoring your server room first to establish a history of normal conditions. Temperature is a significant threat to your equipment and in order to battle this, you need to discover and establish your server room's microclimate (i.e. baselining)!
Baselining is basically achieved through studying the space of your server room while considering the components within it. Thic can be done to determine the proper ranges for both temperature and humidity. So what spots are the most critical for consideration when it comes to sensor placement?
1. Hot Spots
At the bare minimum, place at least one sensor in a central location in the room. Note: every room has its own mini weather pattern and conditions from one part to another can vary based on what the room contains and where vents/returns are located. The simplest rule of thumb is that heat rises so, the higher the sensor placement, the warmer the temperature.
2. Cooling Vent Locations
Whether it is an air conditioner, economized cooler or another chilling device, it will affect the sensor reading depending on proximity of the sensor to the vent. If you want to monitor whether your cooling unit may be going out at different times, place a sensor in the air duct and you can determine when the cooling unit is off. Placement of a sensor in close proximity to the cooling unit may cause the sensor to pick up cooling unit "cycles", sending you false alerts in the process.
Besides cooling vents, you need to also consider hot vents from server cabinets or compressors. Placing a sensor near or in between these areas is crucial as high temperatures can cause damage to hardware. The exhaust-based alerts will draw attention to the high temperatures within the servers, allowing you to prevent loss of hardware (and revenue)!
4. Ancillary Humidification Systems
These systems help control humidity. Too much humidity can cause condensation which leads to electrical shorts. Not enough humidity causes one to have quite the mini-electrifying experience with static electricity at its peak. Place your humidity sensor in a location seperate from the ancillary humidification system in order to prevent the sensor from getting shorted and to avoid false humidity readings.
By monitoring temperature and humidity, one can have early warning of any disasters looming in your server room. It is always better to prevent a disaster rather than mop up after it (speaking of, flood sensors are great too!). If you need assistance in determining the best practices and routines for your server room, please feel free to shoot me an email:firstname.lastname@example.org.