Overlapped FFT based energy detection has been proposed as a signal detection scheme in dynamic spectrum access. The overlapped FFT scheme increases the number of FFT frames to reduce the variance of squared noise and improve the detection probability. Though theoretical analysis and computer simulation of the overlapped FFT scheme have been carried out in the previous studies, it has not been investigated through experiments. This paper evaluates the performance of the energy detection with overlapped FFT through experiments. In the experiments, different from the assumption in computer simulation of previous researches, a fixed distortion component caused by a direct current (DC) offset is observed. Numerical results obtained through the experiments show that the overlapped FFT scheme improves the detection probability by up to 0.15 with the noise and the fixed distortion component. Moreover, the overlapped FFT scheme is also effective on indoor channel models under the existence of the fixed distortion component.