Does the data centre tick all the green boxes?

Be care with the amount of CO2 required for certain data centre designs -- it has to keep with the EU Code of Conduct. Power usage effectiveness (PUE) is used to determine the energy efficiency of a data centre. The power efficiency is the most important factor, and this is what will impact the sustainability of your data centre, so be sure to get this right. If you have a PUE of 2:2, that means you use half the power for cooling, for example, and only half is left to process the servers. Efficiently managing the cooling of your servers is key to the PUE and greenness of the data centre, as it frees up more power for what the servers are there to do -- processing.

For example, using outside air can lower the PUE to 1:5. Depending on where your data centre is located, the outside air may not need to be chilled and it blows air straight into the data centre after it has been through a filter. However, if there is a fire nearby, the filters might not be able to handle the particles being blown into the data centre, so you should still invest in a backup plan. Alternatively, in-house chillers can be used -- these are reliable and take up less space than investing in fans for outside air generation, but can still be costly.

It may be worth looking into a heat exchanger. This isolates the outside air to protect your data centre from any damaging particles, and you will not have to change your filters as often.