Non-domestic gas-fired forced convection air heaters for space heating not exceeding a net heat input of 300 kW, without a fan to assist transportation of combustion air and/or combustion products
用于空间供暖的非家用燃气强制对流空气加热器 净热输入不超过300 kW 不带风扇 以辅助燃烧空气和/或燃烧产物的运输