Every flue erected after June 27, 1949, and every existing flue to be used with a heat generating device or combustion equipment dissimilar to that previously installed or dissimilar to that for which the flue was previously approved, shall be erected or used only if the design and use thereof has been approved by the Commissioner of Air Pollution Control and the Commissioner except that the approval of the Commissioner of Air Pollution Control shall not be required for dwelling house flues or when gas burning equipment is installed.