Is a whole house fan really energy-efficient? Can you gain back the money that you spent on purchasing and installing the system in a few years? A whole house fan is an energy-efficient alternative to air-conditioning units. Though it is more expensive, it offers a higher ROI and saves you money in the long run. These fans claim to reduce an average home's annual electricity bills by as much 90%. That sounds like a lot, but it is certainly possible if you buy whole house fans from trusted brands, install them properly, and use them regularly. Designed to cool your home Knowing how a whole house fan operates will help you understand why it is so energy-efficient. Typically installed in the attic, a whole-house fan is designed to draw hot air out, and bring cool air into the house. It works by pulling the heat or hot air out through the vents, and creating negative space so that outdoor air can come into the living space through the open windows. That is how it is able to redu...