<hwel> 'mine, workings' + <ti> ‘house’ + <Hydin> Personal Name
Historic forms:
Wheal Tehidy 1839 (Illogan and Redruth)(mine, George Jeffery, surgeon of Camborne, adventurer)(*CRO, STA/693c/3, 1839)
Wheal Tehidy 1845 (Samuel Harvey of Kenwyn, purser, John Charles Lanyon of Redruth, adventurer)(*CRO, STA/693c/142, 1845)