My family is about to buy a home and this new home has a central duckt about 2 feet square (with a grill that did now alow me to look inside) on the 2nd floor that goes verticaly through the attic. The current owner's explanation is that is like a skylight with a fan that will suck up the hot air from inside the house and send it througtht that duct outside. He claimed that it kept the house cool enough to not need air conditioning. The house is located on Long Island New York and duckt is on top of a stairway so it might couse sufficient airflow because of the open space of the bottom floor of the house. Please advise as to weather of not this is a good idea weather this works as he said it will.

Sounds like a whole house fan. They are good in tweener weather, say April, May, September, and October once it cools off at night. July and August you will have hot sticky nights where A/C is the only answer.

I have had them in both my houses. They make a great supplement to A/C.