You’ve got two options when it comes to filtered water: point of source or point of use. Point of source means a filter which works on the water before it comes out of the tap, whereas point of use filters the water as it comes out of the tap and before it enters your glass or your mouth. For example, an under-sink filter vs a water cooler.
Both options are great and in both options, your water is filtered – much better than drinking unfiltered water! Deciding whether to choose an under-sink water filter or a point of use water filter is often a matter of space.
Under-sink water systems are the best for small kitchens, particularly those in offices, because they slot in under the sink (often hidden in a cupboard which no one uses anyway) and don’t take up much space. If you don’t have space for an office water cooler, you can still provide filtered water.
The other benefit is that the water is always filtered. A forgetful staff member filling the kettle up from the tap rather than the water cooler won’t be a problem!