One of the biggest challenges of a whole house fan is installation. Whole house fans can vary in prices, but installation is always up in the air. Some whole house fans make it easier to do it yourself, but if you have a belt whole house fan or you just want to make sure it's installed right, you may consult a professional. According to Homeadvisor.com, the cost of hiring a pro ranges from $369 - $876. This may be more or less depending on where you live and how much the contractors charge. Obviously, installing a fan may cost just as much, if not more, than the fan itself, so it may be a little intimidating to pay a pro. Sometimes, you can install it yourself, but if installation looks complicated, you may need to bite the bullet and pay someone. If you mess up, it can cost even more. Also, make sure to choose a contractor who is licensed and has good reviews. That way, you can have more peace of mind.