For urban commercial use of Archimedes spiral horizontal axis wind turbine, its performance involving power output, power coefficient, and effect of aspect ratio or rotor dimensions needs to be enhanced. In order to assess the performance of the turbine, an experimental set-up was fabricated with all necessary measurements. Additionally, the experimental work was conducted on four different Archimedes spiral rotor experimental models having different dimensions and consequently different aspect ratios. The measurements were carried out at various wind velocities. Comparisons among all experimental rotor models were conducted aiming to discover the effect of the rotor dimensional parameters on the performance of Archimedes spiral wind turbine. The results confirmed that increasing both Archimedes spiral rotor diameter and length and consequently the rotor aspect ratio enhanced greatly the power coefficient within the experimental investigation range. The minimum cut-off speed for model (1) was observed to be about 4 m/s. Lastly, model (1) showed the maximum power coefficient while model (4) had the worst performance.