Excel - Formula to extract total time above a specific temperature

I have 100 files, each about 30K lines of data like this:

As shown, the instances are not sequential. I wonder if I can write a formula capable of looking at all instances >0°F, then look at the date/time and add the total time in hrs. It was above that temperature.

I've tried index/match, xlookup, but nothing more streamlined to my problem. What I've tried required a lot of formulas but only adding them manually by segment, not a formula capable of adding a total of n segments.

For this example, the result is 4.1 hours, which was calculated adding the total for each segment found (2) the first is 2.3 hrs (from 9:26:14 - 11:41:14) the second is 1.8 hrs (from 12:01:14 - 13:51:14).

Option with REDUCE:

=LET(
    input, B2:D30000,
    dtime, LAMBDA(i, INDEX(input, i, 1) + INDEX(input, i, 2)),
    val, LAMBDA(i, INDEX(input, i, 3)),
    total_intervals, REDUCE(
        0,
        SEQUENCE(ROWS(input)),
        LAMBDA(acc, cur,
            acc +
                IF(
                    OR(cur = 1, val(cur) <= 0, val(cur - 1) <= 0),
                    0,
                    dtime(cur) - dtime(cur - 1)
                )
        )
    ),
    VSTACK(
        "Total time for all instances > 0°F",
        TEXT(total_intervals, "[h]""h"" mm""m""")
    )
)

With Named Function

To make it easier to apply the formula with multiple inputs, we could define a named function with:

=LAMBDA(input, LET(dtime, LAMBDA(i, INDEX(input, i, 1) + INDEX(input, i, 2)), 
val, LAMBDA(i, INDEX(input, i, 3)), 
REDUCE(0, SEQUENCE(ROWS(input)), LAMBDA(acc,cur, acc 
+ IF(OR(cur = 1, val(cur) <= 0, val(cur - 1) <= 0), 0, dtime(cur) - dtime(cur - 1)))) * 24))

then apply with different ranges

=totalHoursForAboveZero('path[filname]sheet'!range)

or 

=totalHoursForAboveZero(B2:D30000)

Adding formula via VBA

• Break into parts with length < 255
• Prepare double quotes

Just a quick suggestion to set the formula only - you can fit it into another routine for adding into multiple files.

Sub InsertTotalTimeFormula()

    part1 = "=LAMBDA(input, LET(dtime, LAMBDA(i, INDEX(input, i, 1) + INDEX(input, i, 2)), val, LAMBDA(i, INDEX(input, i, 3)), total_intervals, REDUCE(0, SEQUENCE(ROWS(input)), "
    part2 = "LAMBDA(acc,cur, acc + IF(OR(cur = 1, val(cur) <= 0, val(cur - 1) <= 0), 0, dtime(cur) - dtime(cur - 1)))), VSTACK(""Total time for all instances > 0°F"", TEXT(total_intervals,  ""[h]\h mm\m""))))"
    inputRange = "(B2:D30000)"
    
    With ActiveWorkbook.ActiveSheet
        Range("H4").Select
        Selection.Formula2 = part1 & part2 & inputRange
        Selection.Columns.AutoFit 
    End With

End Sub