Top: evolution of the Joule heating at the footpoints of the loops below z = 1.2 Mm in the chromosphere (dotted line, left axis) and 3 Mm above the transition region in the corona (solid line, right axis) for loops L1, L2, and L3. Red and blue plots correspond to the heating evolution at the left and right loop footpoint respectively. Bottom: evolution of density of the plasma integrated along the coronal portion of the loop (dotted line), and average temperature in the coronal part of the loop (solid line) for L1, L2, and L3.