There are already some datacenters doing this: https://www.techtarget.com/searchdatacenter/tip/Data-center-heat-reuse-How-to-make-the-most-of-excess-heat https:

There are already some datacenters doing this: https://www.techtarget.com/searchdatacenter/tip/Data-center-heat-reuse-How-to-make-the-most-of-excess-heat https://www.techtarget.com/searchdatacenter/tip/Data-center-... But for now, it's still the exception, probably because of the cost of such systems.