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It’s often forgotten but air conditioning is mandatory in every data centre and server room. So what happens when the main air conditioning shuts down for maintenance, or worse, it fails? Active Air Rentals director John Sweeney explains HVAC contingency planning.

Unlike Google or Facebook, most organisations cannot set up their data centres in sub-Arctic towns for optimised cooling. And although low-heat emitting servers are now available, they are still relatively new to the market.

So when modern data requirements or heat waves cause servers to heat up, it’s the responsibility of an average building’s HVAC system to keep them cool and working. But what if the HVAC systems fails and what happens during scheduled maintenance? That’s where a robust HVAC contingency plan comes in.

“HVAC contingency plans basically analyse the business impact of a HVAC breakdown or scheduled outage and then detail the required cooling equipment and action plan,” Sweeney says.

To start HVAC contingency planning, organisations should first identify the consequences of an HVAC outage in the data centre.

Questions should cover how dependent are business operations, information systems and other data centre resources on the HVAC system? Given that most servers need to stay well below 24°C, how long could the data centre go without cooling?

Once those questions have been answered, the next step is to qualify and quantify the business effect and related costs. What would a HVAC outage cost for an hour, a day, or a week?

Latest research suggests that the average cost of server downtime is $5000 per minute. That’s a whopping $300,000 per hour; a conservative time estimate for an emergency situation.

Given the costs, when is the optimal time to schedule HVAC maintenance to minimise the effect on business?

The next step is to create a temporary cooling plan to ensure data centre cooling continuity. This part of the plan identifies suppliers and key equipment.

“Temporary portable air conditioners are now the default choice for keeping data centres and server rooms cool during maintenance; to be effective, portable air conditioners must be deployed quickly. Quick deployment requires knowing room size, power supply, extraction points and other variables.

“Specifying these variables takes up valuable time so it’s better to pre-specify them.”

Key plan components

A robust contingency plan should include the following information and be kept on file with the temporary cooling supplier for instant access in case of an emergency:

Size of data centre/server room
Size of the failed unit/s

Number of temporary units required
Available power supply

Hot air extraction points
– where and how many

How cool air will be distributed – direct
or ducted. If ducted how much is required?

How many cables are required
How many extraction fans are required

How condensate will be removed
Who to liaise with and how to access the site and pass security.

“HVAC contingency plans are free, minimise risk and make facilities managers’ jobs easier,” he says. “There’s really no reason not to have one.”

Sweeney says Active Air Rentals uses the latest in portable air conditioners ranging from 3kW for small server rooms to the unique 20kW for large data centres.

All units can be wheeled through a standard doorway, plug into standard 10amp sockets and vent hot air through temporary ducting.

The company has over 40 years' experience.  For more information about Active Air Rentals visit www.activeair.com.au.