Whole-house fans are a low-cost cooling solution. Their use is in decline, but in favorable weather conditions they cool an entire house in a couple of minutes at a fraction of the price of cooling it with an air conditioner.
Whole-house are relatively inexpensive (some few hundred dollars) when compared with central air conditioners, and their running costs are estimated at 1/10 of the costs of AC.
But whole-house fans have also limitations and possible downsides.
Effectiveness & Limitations
Whole house fans are most effective in hot climates with dry weather and cool evenings. With whole-house fans you will have to wait until outdoor temperatures drop below 70ºF/21ºC before ventilating the house.
On the other hand, to keep your home comfortable during the day, you have to close the house and the windows, to keep the cooler air inside; and your home should have reasonable or high levels of attic and wall insulation, and shaded windows (to prevent heat gains during the hotter parts of the day)...
Noise & Installation
Whole-house fans can be noisy, namely more traditional models. To minimize or reduce the noise, look for a quieter model and pay special attention to its installation. You should install the fan on rubber or other similar materials, able to dampen the noise.
Also to reduce noise, buy a properly sized and multi-speed fan (instead of a single-speed unit). The idea behind it is simple: a fan running at a lower speed makes less noise than a smaller fan operating at high speed.
Installing a whole-house fan may require structural modifications to the ceiling or roof framing and also an opening that can be a potential source of heat loss during the heating season.
To minimize these risks, prefer a fan with an in-built insulated door, able to completely seal the fan and its opening when the fan is not in use.
Whole-house fans installed in attics may also require extra roof venting.
Yes or no to whole-house fans?
That depends a lot on your climate and your options. If you live in a hot-dry climate with cool nighttime temperatures, whole-house fans are a good choice for energy savings and comfort. Contrary to air conditioning, it will require some commitment from you (you will have to open and to close the windows or dedicated outlets, according to the outside temperatures, and be aware of their installation requirements).