# Whole house fans **URL:** \ **Category:** Factual Questions\ **Created:** [July 18, 2018, 10:42pm UTC](https://boards.straightdope.com/t/whole-house-fans/818171 "2018-07-18T22:42:35Z")\ **Posts on this page:** 1\ **Showing post:** 33
**Author:** ![Khendrask](https://avatars.discourse-cdn.com/v4/letter/k/3e96dc/32.png) [@Khendrask](https://boards.straightdope.com/u/Khendrask)\ **Post date:** [July 25, 2018, 2:42pm UTC](https://boards.straightdope.com/t/whole-house-fans/818171/33 "2018-07-25T14:42:13Z")
> [@CookingWithGas](#): > > I would think it would be the opposite. The more windows that are open, the less force the fan has to exert to pull the air in. Extend this to an extreme: Suppose you have only one window open a tiny crack. The fan has to try to suck a large volume of air through that tiny crack, creating a negative pressure in the house, and a big load on the fan. Now go to the other extreme: you have no walls. There is no pressure differential inside vs. outside and the only significant load on the fan is from pushing the air into the attic. That is backwards. A normal fan, or centrifugal pump only draws current as it is moving the working fluid. Block off the intake, and the motor current will drop as no work is being done. The most common example of this is a shop vac. Block the inlet hose, the motor speeds up, as it isn’t delivering torque to moving any air. --- _[View the full topic](https://boards.straightdope.com/t/whole-house-fans/818171)._