Please find here two files: the first one is the umf4hb.f90 file that calls the C-interface to UMFPACK4.1. The second is an addition that performs several sparse-matrix operations that can be helpful with the use of UMFPACK:

1. The code of umf4hb.f90 is here.
2. The code for the sparse matrix utilities can be found here.
3. The f90_kind.f90 module (used with the F-compiler) here.

We have also a site on heat transfer simulation