We have developed a new innovative plate-type heat exchanger using thin aluminum foil sheet that significantly reduces the indoor pollutants with a minimum loss of energy. The thin aluminum foil sheet has a thickness of 17μm, and having a width of 330 mm and a length of 1,510 mm. The heat exchanger consists of 45 layers of aluminum foil sheets which are placed on top of each other with a spacing of 7 mm. The exchanger is structured such that air dust and pollutants can be effectively filtered as the air stream passes through the heat exchanger. The experimental results show that the concentration of carbon dioxide inside the office room is reduced to as low as 650 ppm, while maintaining the room temperature difference to within ± 1 degree Celsius before and after operating the present heat exchanger. This device can be installed in any indoor places that need the good air quality control with a little sacrifice of energy consumption.