In this work, we study the effect of initial turbulence on turbulent premixed combustion (vented deflagration) simulations using PDRFoam. The PDRFoam solver is based on Cartesian method that takes into account complex geometries, however, always models quiescent initial conditions, which does not represent real world industrial scenarios. The Nine-pipe bundle CMR experimental case, which uses stoichiometric methane-air as fuel, is used as a base case to study the sensitivity to various initial turbulence conditions. This is carried out by varying the initial turbulence intensity as well as its spatial distribution in the domain. The results obtained for different initial intensities agree with experimental studies in the literature. Investigating the sensitivity of PDRFoam to such initial conditions will make it even more suitable as an open-source alternative for deflagration modeling.