BTU (IT) per hour to BTU (IT) per second conversion calculator shown above calculates how many BTU (IT) per second are in 'X' BTU (IT) per hour (where 'X' is the number of BTU (IT) per hour to convert to BTU (IT) per second). In order to convert a value from BTU (IT) per hour to BTU (IT) per second (from BTU/h to BTU/s) just type the number of BTU/h to be converted to BTU/s and then click on the 'convert' button.