Whole house fans can be purchased at your local home supply store such as Home Depot or Lowes. In either situation they supply more than one brand and more than one type. This is where a discussion with your contractor will help you decide which one is right for you and your home. Also, in either situation the whole house fans operation is not complex; however, understanding of the operation can help you in your discussions with your contractor.
In simple terms the whole house fans works by pulling cool air from outside the home, drawing it up through the whole house fan and then up and out through the attic space which then exhausts through the required ventilation. This also allows for the cooling of that attic space which a standard central cooling unit will not do. This is one of the key elements of the whole house fan operation, because when your attic space holds heat you can feel it in the house. Since the whole house fan is designed to pull air from the outside in you only want to run it when the outside air temperature are cooler than the inside of the house.
We have found in our own home that running the whole house fan through the night keeps the cool air circulating and we do not have to run our A/C during this time. Also by doing this we have prepared our home for the next days heat. PG&E states that a whole house fan can keep you comfortable in the summer for about 20% of the cost of running your central air conditioning. I can say personally that I have seen the savings in our own home. Now, many people ask about the noise and are they really "whisper quiet" as many advertise.
In our home a little white noise is not a problem. As a matter of fact I sleep well to white noise, but not everyone does. Whole house fans definitely make noise. I have not met one yet that sounded "whisper quiet". However, I can say that the noise emitted is more than reasonable and over time it goes unnoticed - at least in my own personal experience. The sound can be compared to any free standing, large fan that you might have used in your home in order to cool it. Whole house fans do come in various sizes and brands so our recommendation is talk to your contractor on which one might be best for your home.
In this area we typically install the 24" direct drive or the 30" belt drive. Considerations for purchasing a whole house fan include the available space in the home for the placement of the whole house fan itself as well as meeting the required attic ventilation. The advantage of the 30" is that it can be considered quieter since the fan runs independent of the motor and uses a belt to drive it.
As a contracting business in this area it is important to note that permits are required for whole house fan installation. The phone number to the Folsom's Planning Counter is 916-355-7214. Rebates are also available through the city.
I hope this information has been helpful. Please feel free to contact and discuss a whole house fan for your home before the hot weather hits!