Sec. 15. As the tax is collected, the levies become a part of the hospital funds without further appropriation by the county fiscal body and may be invested in accordance with IC 16-22-3-20. The levies shall be separately accounted for as a hospital cumulative building fund and may not be used for any purposes other than that for which the cumulative building fund was established, except for the following:
(1) A lease entered into with an authority or the Indiana finance authority under IC 5-1.2-7 may provide that the lease agreement to pay lease rentals be paid in whole or in part from the hospital cumulative building fund.
(2) If a loan has been obtained for the same purposes for which the cumulative building fund was established, the fund may be used to pay principal and interest on the bonds, notes, or other evidences of indebtedness of the hospital.