Simple solution for temporary or permanent effective ventilation To quickly and easily provide rooms with effective ventilation, Mark has developed the ERV MOBILE. This mobile ventilation unit has the interior of a Mark ERV 1000 and a housing painted in RAL 9010. This mobile heat recovery unit is the ideal solution for energy efficient ventilation and a comfortable indoor climate. The ERV MOBILE fits through all common doors and is equipped with wheels for easy movement and is therefore very suitable for schools, nurseries, offices, churches and other public spaces.