Data Centre Resilience – a new way of thinking


The saying goes that “two are better than one because they get a good return for their labour.” It might be straight out of scripture, but we couldn’t agree more when it comes to data centres.

Across the world we stick to the N+1 idea of keeping a backup cooler on site, just in case the main one goes down. Everyone does it, because its essential practice for ensuring websites and databases stay online, especially if there’s ecommerce transactional platforms or if they are used by thousands of internet users.

But whilst this is the norm, we think there’s a better solution.

A task shared is a task halved

We’re an advocate of running both pieces of cooling kit at the same time. Why?

Running two coolers will:

  1. Protect your standby equipment from failure
  2. Give you an annual reduction in pump power
  3. Massively reduce noise emissions
  1. Maintenance issues – If the redundant equipment is not operated regularly then it runs the risk of becoming faulty and then going unnoticed until it is required in emergency conditions.  This is absolutely the worst time to discover any flaws as they will render the standby system useless.  Operating it in parallel with the primary cooler means that issues such as fan motor bearings seizing up or any other unforeseen costs can be avoided.
  2. Reduction in pump power- Based on a typical 500kW condenser water cooling system, running two coolers instead of one makes the annual power consumption actually go up by 9MW. But – the annual reduction in pump power, caused by halving the flow through each cooler with a resulting drop in pressure, gives a saving of 13MW – which gives a net annual saving of 4MW, a saving of around £400 at an electricity cost of £0.1/kWh.This is because a reduction in pressure drop is proportional to the square of a drop in flow rate – e.g. 0.5² = 0.25.  Based on the same 500kW example this would reduce pump input power by 1.6kWh, giving the 14MW annual saving.There’s also the knowledge that you’re reducing your carbon footprint too by approx.27 tonnes.
  3. Massive noise emission savings –Lastly, due to the reduction in fan speed at peak design operating conditions, two coolers running together can reduce noise from 65 decibels to 46 decibels (which is the equivalent of only 1/75th of the noise of one cooler working).So there’s a lot to gain from running both together. Net energy savings, noise emission reductions and definite maintenance and plant lifespan improvements. And having two cooling machines working together also means that N+1 can still kick in if one of them should fail. Talk to us about what’s the best option for your project.