The exponential and piecewise exponential functional forms exhibit similar carbon footprints due to the comparable working capacities. However, there is a difference in the DAC process cost. The initial steeper capacity decline in the piecewise exponential functional form leads to a slightly higher process cost initially compared to that of the exponential form. However, this is reversed at longer lifetimes due to lower degradation rate of the piecewise exponential function after its initial decline. In a scenario where we have to choose between these three sorbent options, the most economically favorable choice would be to use the sorbent displaying linear decay and replace it every year. However, the most economically favorable choice will depend on the sorbent parameters in the scenario; different initial working capacities and degradation rates will lead to a different result. Without the capacity fade economic model, the answer would be ambiguous.