Hi, I have reviewed the datasheet for the Cisco 100 Series Unmanaged Switches and found that they are fanless to Reduced energy costs: Cisco 100 Series switches are designed to help conserve energy by optimizing power use without compromising performance, which protects our environment and reduces your energy costs. In addition, they support the Energy Efficient Ethernet (IEEE 802.3az) standard, which reduces energy consumption by monitoring the amount of traffic on an active link and putting the link into a sleep state during quiet periods. Most of the switches have no fans, so they run silently and unobtrusively while lowering energy costs.