Core Drilling with Dry Core Bits vs Wet Core Bits

When core drilling, it is always best to use a Wet Core Bit.  Why?  Faster drilling, flushing out of cut, dust control, minimize binding in cut, bit lasts longer, thicker more durable wall (fewer broken segments).

So why use a Dry Core Bit?  There are times when water is simply not accessible or slurry from wet drilling is not acceptable in the environment. 
In that case, using a dry bit on a standard handheld core drill or a core drill rig is the next best choice.  A dry bit can be used on a rotary hammer drill (with hammer turned off) in conjunction with an adapter but RPM’s are typically slower and precise control over the bit while using an adapter is not desirable.  The clutch system on a dedicated core drill is preferable when core drilling vs a rotary hammer. 
Block, brick, or soft concrete are still the only recommended materials to use a dry core bit to drill.  Horizontal drilling is preferable to vertical when drilling dry because the dust is not extracted efficiently leading to slower drilling and more binding of the bit.

A dust "muzzle" can be used with a vacuum to contain the slurry from wet drilling or to contain the dust from dry drilling.

Material:

Equipment:

Depth of cut drilling wet (left) vs dry (right) in the same amount of time on identical hand held core drills into concrete.

Video of Wet Core Drilling vs Dry Core Drilling on Hand Held Core Drills.