What Temperature Should a Server Room Be? (Australia)
What Temperature Should a Server Room Be? The Australian Guide to Optimal Setpoints
Quick answer
A server room should generally be maintained between 18°C and 27°C, with relative humidity in the 40 to 60% range. This aligns with the ASHRAE recommended envelope used by data centres globally. Within this range, IT equipment operates reliably, energy costs stay reasonable, and component lifespan is maximised.
For most Australian server rooms, a setpoint of around 22 to 24°C at the cold-aisle inlet is the sweet spot: comfortable for staff working in the room, safe for hardware, and energy-efficient.
The ASHRAE recommended range explained
ASHRAE (the American Society of Heating, Refrigerating and Air-Conditioning Engineers) publishes the global benchmark for data centre environmental conditions. Their TC 9.9 guidelines are referenced by virtually every major server, switch, and storage vendor.
The current recommended envelope:
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Temperature: 18°C to 27°C
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Relative humidity: 40% to 60%
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Dew point: 5.5°C to 15°C
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Maximum rate of change: 5°C per hour
There is also a wider allowable envelope (15°C to 32°C) where equipment will still operate, but reliability and warranty risk increase. Most operators stay inside the recommended band for good reason.
Why temperature control matters more than you would think
Servers are surprisingly tolerant of warm air, but only up to a point. Once you push past the recommended range, several things start to go wrong:
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Component lifespan drops. Electrolytic capacitors, in particular, halve in life roughly every 10°C above their rated operating temperature. Hard drives show similar sensitivity.
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Throttling kicks in. Modern CPUs and GPUs reduce clock speeds when temperatures rise, costing you the performance you paid for.
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Fan power spikes. Server fans ramp up exponentially. A 5°C rise in inlet temperature can double fan power consumption across an entire rack.
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Failure rates climb. Industry studies consistently show that every 10°C above 25°C roughly doubles equipment failure rates.
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Warranty risk increases. Many vendors void warranty cover for sustained operation outside the recommended range.
Inversely, running too cold is not free either. Cooling below 18°C wastes energy without improving reliability and risks condensation if humidity is not tightly controlled. A properly sized precision cooling unit handles both ends of the range with much less drift than comfort air conditioning.
Hot aisle vs cold aisle: where do you actually measure?
This is one of the most commonly missed nuances. The 18 to 27°C target applies to the air entering the front of the equipment, the cold aisle inlet, not to the room average and not to the hot aisle return.
In a typical hot aisle / cold aisle layout:
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Cold aisle (front of racks): target 22 to 24°C
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Hot aisle (rear of racks): typically 35 to 45°C, and that is normal
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Room average: somewhere in between, but largely irrelevant
If your only temperature sensor is on the wall or ceiling, you may be measuring something halfway between the two and missing real problems at rack level. Best practice is inlet sensors at the top, middle, and bottom of representative racks.
Humidity: the other half of the equation
Temperature gets all the attention, but humidity is just as important.
Too dry (below 40%):
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Static electricity discharge risk increases sharply
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Sensitive components can be damaged by ESD events
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Tape media and some optical components degrade
Too humid (above 60%):
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Condensation risk on cool surfaces
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Corrosion of contacts and circuit boards
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Mould and contamination on filters and surfaces
In Australia, the climate adds nuance. Brisbane summers can push outside humidity well above 80%, while inland and high-altitude sites can get very dry. Your CRAC unit's humidification and dehumidification systems need to handle both extremes.
Recommended setpoints for Australian server rooms
Based on what we see across our clients in Brisbane, Sydney, Melbourne, and regional Australia, these are sensible starting setpoints:
Tuning these setpoints, especially the deadbands, can save 10 to 20% in cooling energy without any reliability impact.
Energy efficiency: should you raise the setpoint?
Many operators ask whether they should push setpoints higher to save energy. The answer is "yes, but carefully."
Every 1°C increase in setpoint typically saves 2 to 5% of cooling energy. Major hyperscalers run their facilities at 25 to 27°C inlet temperatures and have the data to prove it works.
For most Australian businesses, the practical advice is:
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Audit your current actual conditions at rack inlet level, not just the wall sensor.
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Tighten airflow management first, including blanking panels, brush strips, and aisle containment.
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Raise the setpoint in 1°C steps over several weeks, watching alarms and IT logs.
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Stop when you reach 24 to 25°C unless you have very modern equipment and tight monitoring.
The savings are real, but they only apply once airflow is properly managed. Raising the setpoint in a leaky room just makes hot spots worse.
What about small server rooms and IT closets?
Not every business runs a Tier III data centre. For smaller environments, including branch office racks, edge sites, and IT closets, the same principles apply, just scaled down:
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Aim for 22 to 25°C in the cabinet
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Use a dedicated cooling unit, not the office air conditioning
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Add temperature monitoring with email or SMS alerts
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Ensure cooling runs 24/7, including weekends and holidays
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Do not rely on the building HVAC turning back on Monday morning
We see far too many small businesses lose hardware over a long weekend because their office cooling shut down on Friday night. A small dedicated unit and a temperature alert solve this problem permanently. Our CRAC installation team handles small server rooms across Brisbane, Sydney, and Melbourne.
Monitoring: you cannot manage what you do not measure
Modern environment monitoring is cheap and effective. At a minimum, you should have:
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Inlet temperature sensors at multiple rack locations
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Humidity sensors in at least one location per room
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Leak detection under raised floors or near CRAC units
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Alerting by email or SMS to the right people
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Trending over time, not just instantaneous readings
The goal is to spot a slow drift before it becomes an alarm, and certainly before it becomes an outage.
Frequently asked questions
What is the ideal server room temperature in Celsius?
The recommended range is 18 to 27°C, with most operators targeting 22 to 24°C at the cold-aisle inlet for the best balance of reliability and efficiency.
Is 25°C too hot for a server room?
Not at all. 25°C is well within the ASHRAE recommended range and is increasingly common in modern, energy-efficient data centres.
What humidity should a server room be?
40 to 60% relative humidity is the recommended range, with 50% being a sensible default.
Where should I measure server room temperature?
At the air inlet to the front of representative racks, not on the wall, ceiling, or in the hot aisle.
Do small server rooms need the same conditions as big data centres?
The conditions are the same. The equipment to achieve them is just smaller. The physics of electronics does not change with room size.
For more answers, see our UPS, battery and CRAC FAQ page.
Need help dialling in your server room conditions?
If your room is running too hot, too cold, or you simply do not know, we can help. Our team carries out thermal surveys, environment audits, and CRAC tuning across Australia.
Contact our team for a server room assessment, or browse our precision cooling range for monitoring or CRAC upgrades.
