Odor is "24V DC Cooling Fan" odor varnish coating on the copper produced at the time of the operation, in the purchase of fans have to smell it, to see this paint is environmentally friendly, whether through quality testing, let you in the fresh enjoy the wind in the air cool. The "24V DC Cooling Fan" safety requirements, national standards set forth very detailed, consumers also can be a simple test. Qualified fan, general adult fingers can not touch the fan grille and front, families with young children should choose dense fan grille. When consumers buy "24V DC Cooling Fan", to look at the instructions to see if the mandatory certification quality system certification, whether there is inspection standards certification; and now promote "green carbon", depends on whether the national one level of energy efficiency standards.