Comment by ryao

Storing pictures and emails in a data center does generate heat, but it is negligible. Also, claims of data center water usage are heavily overstated. Some do, but only during summer months. I assume the reason for the UK’s asinine advice is because of they think there is a link between heat generation and water usage at data centers. While a link does exist, it is not straight forward.

I have only ever toured a data center once, but the one I toured had no water usage by the cooling infrastructure as far as I could tell. However, the facility’s APUE was something like 1.7, which is high. I have read that some facilities with impressively low APUE numbers use water during particularly hot summer days, which is presumably for evaporative cooling. Unfortunately, I have yet to see one of these facilities in person to know the details beyond what has been publicly written.

If it counts for anything, I have hundreds of commits in OpenZFS. I know some things about data centers from a mix of professional contacts since my work is used in them (which is how I got the tour in the first place), and personal interest in the subject, but I am far from an expert on all aspects of how data centers work. Speaking of which, I doubt there is any one person who is an expert on all aspects of how data centers work, since the knowledge is spread across multiple types of experts. A physicist would not be my first choice of expert when asking questions about data centers. A data center technician would be a better person to ask.