| Indices | Parameter | Value | Units |
| Tr TC Th QAir XP WP | Ambient temperature Initial temperature Inlet water temperature Air flow rate Pitch length of metal rods Width of the polyethylene tube | 21 21 45 9.5 × 10−5 5, 6, 8, 10, 12, 14, 15 15, 20, 25, 30, 35 | ˚C ˚C ˚C m3/s cm cm |