Urban residential housing 40~ 100
Office 100~ 150
Urban street green belt 100~200
City park 400~600
Suburb and wilderness 700~ 1000
Forest and coast 1000~3000
It is known that to achieve the forest-like effect indoors, the concentration of negative ions must reach 1000 /cm3 per second, which is generally impossible unless the room is in a forest or near a waterfall. However, even if it is impossible to control the whole room to maintain a high concentration of negative ions, there is another way that is popular in recent years, that is, the negative ion energy product developed by nanotechnology, and there is an i-pure brand negative ion energy ornament on the market. According to the measurement, the content of negative ions released by it is controlled at 1000 units, which is said to be the highest among similar products on the market at present. When people wear it with them, it is just like the concentration of negative ions when it comes into contact with the forest, so this product is often the best choice for giving gifts.