i'm not aware of an automatic solution to your question, but I doubt it would work well anyway. the point of the whole house fan is to pull large volumes of fresh air into the house and out through the attic to cool the house. this won't be accomplished by simply recirculating the existing air through your house. it also won't work well at all by simply installing a small duct somewhere in your house. doing that will only cool the areas on the path of air flow between that duct and the fan - all the remaining rooms will stay hot. opening a couple of windows really isn't that big of a deal. i've found that opening one on either end of the house (repeating on each floor) does the trick perfectly. i used an airscape whole house fan (see link below), which has a 7 foot noise dampening duct between the fan and the opening in the ceiling. it is very quiet. the unit also has damper doors that automatically open and shut when the unit is powered on and off to keep a tight seal between the living area and the attic. Here is a link that might be useful: Airscape

"As I understand it, there is to be a 1/4" nailing strip installed on each side, for a total of 1/2" for each dimension, which is why the rough dimension is quoted as 1/2" larger." That is not the reason for the rough opening being 1/2" larger. You need to look at a window. The nailing strip is actually a 1 1/2" +/- flange that overlaps the rough opening and is nailed to the sheathing so the gap between the window frame and the framing does not have to be exact or perfect. The framer will treat the specified R.O. as a minimum and try to make it as square and level as possible. A slightly larger opening is not a problem. You only need to tell the framer the R.O.'s and the only reason to modify them is if you wanted to use a sill pan or another kind of sill flashing that required more space. A long span over a set of windows might require a larger gap at the head for future deflection. Adding to the specified manufacturers R.O.'s can result in redundant increases in the final opening size so such increases are better shown in a note in the window schedule with an asterisk at the R.O. for the appropriate window. Many designers have gotten into the habit of showing a frame size on the elevation drawings. That is OK for vinyl and fiberglass windows and perhaps clad wood casements and awning windows but for many double-hung windows the frame size is not an even dimension (windows sizes are a function of standard glass sizes) and varies a lot between manufacturers. The solution is to pick a manufacturer and put everything into a window schedule. If the manufacturer is changed all of the R.O.'s will have to be changed.

Like items on this site (but US company, not UK) http://www.window-openers.com/rv2900_battery_window_opener.html

The door goes beyond that. It will swing to 140-150 degrees. It's an solid, simple machine. No bells or whistles, but works and shouldn't have too many issues. Electrolux (parent company of Frigidaire) is the largest manufacturer of front load laundry in the world after all! Also check out the FFFS5115PW which is the same machine, but with steam. That's the model Frigidaire promotes the most so some times you can get steam for little or no additional expense.