General recommendations suggest that you should not go below 10°C (50°F) or above 28°C (82°F). Although this seems a wide range these are the extremes and it is far more common to keep the ambient temperature around 20-21°C (68-71°F). For a variety of reasons this can sometimes be a tall order.

How do you maintain the right temperature?

Purpose built server rooms are well insulated for fire precaution reasons and air conditioning is essential. In many companies however the maintenance of the air conditioning is separate from the running of the servers. If the air conditioning fails you might not be the first to know. You may even be the last.

Even if everything is working the temperature may fluctuate during the day, from season to season, and there is always the possibility of localized hot-spots around equipment giving off lots of heat.

Don’t be tempted to think that just because you have an air conditioning unit that is up to the job that you are safe. People working in the server room sometimes switch the air conditioning off and forget to turn it on again. Sometimes they leave doors open. Servers run hotter at some times of the day than at others, air conditioning systems sometimes run at lower power at night etc.

What if it’s night time, your air conditioning is running at low power, and your webserver suddenly starts to work hard because the west coast has woken up? Now your machine heats up and your air conditioning can’t cool it enough. Exactly this scenario has been know to happen. Many intermittent faults and slow downs can be traced to overheating.

Replacing old equipment can introduce a new set of problems. Newer machines run faster and often run hotter as well, increasing the burden on the air conditioning systems even more. If you’ve recently introduced new servers or modern switches, it might be time to examining your air conditioning unit to make sure it can still keep up.

Another thing to look out for is the scenario where you turn up the air conditioning unit during the day, in order to ensure the right environment in your server room, but then don’t switch it down during the night or weekends. During the day there might be a lot of activity into and out of the server room. The server room door being opened all of the time lets warmer air into the server room thus necessitating the air conditioning system to be turned up high. At night and at the weekend, without the same level of activity, you may be running up large energy bills for no reason.

How are you going to monitor the temperature?

You need to monitor the temperature in your server room all of the time, especially at night and weekends when nobody is around. A number of systems are available for this purpose, the Temperature Monitor range from OPENXTRA offer good products at reasonable prices. You need to measure temperatures at different points in the room to get an idea of where the hot spots might be. You need temperature measurement to be automated and reliable, so a network attached device is ideal. The device must support alarms, via a number of different methods like email or SMS. You should be able to set the system up and then be alerted when something is wrong.

Information Source: https://www.openxtra.co.uk/kb/environment-monitoring/recommended-server-room-temperature.html