To mitigate the concentrations of fine particulate matter in livestock farming areas, techniques are needed which reduce emissions from poultry barns. In this pilot study, measurements were carried out on the Octafil system of the company VEKO Ventilatie, installed inside a layer barn. The system filters particles from the exhaust air flow and then partly recirculates the air back into the poultry house. In deviation from the measurement protocols, the so called “fine dust pilots” included one (instead of two) farm locations. The measurements show that the emission rate in the situation of filtration and internal recirculation is not statistically different from the emission rate in the situation without filtration. Measurements on the removal efficiency of the filter showed a statistically significant reduction of on average 36%. This is almost the same as established in earlier measurements on the dry filter wall (Rav E 7.4; 40% reduction) from which the Octafil system is derived.