Perennially confined crawl space lacks outside air circulation, causing moist air collect in the space. Prolonged moisture causes to grow and wood to rot, which affects the structural integrity of the wood. Wet wood also attracts annoying groups like reptiles that gnaw and erode, causing additional damage to the wood. What's more, airborne spores enter your living space through floors and cracks and even crawl space hvac, thus creating indoor air pollution that will endanger you and your family's health.Alorair underground ventilation system can easily solve for you, the crawling space fan simply discharges moist and stale air from the confined space, so that fresh air from the outside can enter, more effectively removing excess heat, moisture, dust and odor in various spaces. Whether it's crawl space, basement, garage or carpentry workshop. Installation matters: crawlspace fans must be installed in electrical control boxes and motors facing inside the crawlspace.1. Confirm that the doors and vent covers of the buildings around the installation are open.2. In order to ensure the stable installation of the crawling space ventilator, it is necessary to mark four points on the wall to confirm the installation position.3. Install the crawl space ventilation fan to the wall with 4 screws and observe the horizontal direction of the fan.4. Note:if the mounting surface is a base block or brick. Before the fan is installed, a 5 16-inch hole needs to be drilled with a masonry drill...