The present invention is to provide a system for filtering air in an enclosed space. The system comprises at least two filtering unit, a first filtering unit and a second filtering unit arranged opposite to each other for filtering and circulating filtered air therebetween. The first filtering unit and the second filtering unit includes a blower, a filtering member, an inlet and an outlet. The air from the surroundings is drawn into the first filtering unit and the second filtering unit and the filtered air is circulated between the first filtering unit and the second filtering unit ensuring a cyclic filtration process.