Hi There !

Do you have a crackpot uncle with wild schemes that only work
occasionally?
That's me!

I would like to devise a system using high-velocity fans to rapidly
evacuate warm air (and replace it with cool air from outside) in my
house in the evening.

Please assume the following:

3000 square foot house 
12 foot ceilings
House on one level
64 degrees outside at 8 PM
80 degrees inside at 8 PM

My goal is to reduce the temperature to 70 degrees inside as quickly
as possible.  Seems to me there are 3 ways to do this:

1.  Set a number of minutes to accomplish the temperature change, and
then buy a big enough fan to accomplish the goal
2.  Set a number of minutes to accomplish the temperature change, and
then buy enough individual fans (rated 20,000 CFM) to accomplish the
goal
3.  Buy two fans at 20,000 CFM (one fan pumping air in and one fan
pumping air out), and simply accept the number of minutes required to
accomplish the goal

This is not a mathematical question.  I never was much good at, "One
train leaves Pittsburgh traveling west at 50 miles per hour..."

Rather, this is a conceptual question.   A 5-star answer would be 1-2
paragraphs on how to rapidly evacuate a space----replacing "stale" air
with "fresh" air.  I would also be fascinated to know if such "rapid
air exchange" is successfully used in home or industry elsewhere in
the world, but this is not required to answer the question.

All comments greatly appreciated !

Thanks.
Uncle Ron

The rate of exhaust of the  fans operating in parallel are additive

ventilation FAQ  
     http://www.aivc.org/Faq/faq.html       


    I would be disappointed if my 'mad uncle' would just install some
fans,
  without considering  integrated HVAC, computer controlled system ...
    with " Dataloggers, kilowatt-hour meters and a water meter (not
shown)
monitoring system performance..." 

 Here, such ideal mad uncle is picuted with his system:
    http://oikos.com/esb/41/eahpstudy.html


          "..operating a fan or blower at full speed continuously, or
cycling it on and off, is a sub optimal solution in most
 cooling and ventilating applications   ..."
     http://www.controlres.com/adaptive_cooling.htm     


     In the present study on zone cooling system in greenhouse,
influence of air temperature inside cooled space, ventilation rate and
shading on cooling load and CO2 concentration was analyzed
experimentally :
   http://www.actahort.org/books/440/440_43.htm   
 http://students.washington.edu/dclang/temp.html

    A well-constructed environment accommodates a broad range
 of human comfort with heating, ventilating and cooling (HVAC) systems

 I would expect him to consider heat pump for cooling/heating too:
              http://www.heatpumpcentre.org/activity/hpc_dist.htm
                http://www.aivc.org/Publications/Biblipgraphy/BIB05.htm

     or more information on residential commissioning contact (e.g.)
                                        
http://epb1.lbl.gov/commissioning/perform.html


 SEARCH TERMS
     ventilation temperature cooling  
          ventilation temperature cooling 
                 heat pump ventilation   cooling

---

Clarification of Answer by hedgie-ga on 14 Sep 2003 17:17 PDT

Correction: (it should be "For", not "or") like this:
     For more information on residential commissioning contact (e.g.)
                                        
http://epb1.lbl.gov/commissioning/perform.html
 
  And if you click on links, it leads to interesting info, like:


Companies: Whole House Cooling Fans (15850)

http://oikos.com/esb/40/tamarack.html

Thanks, hedgie!  I especially enjoyed the Greenhouse study from Japan.
 Great job!    Uncle Ron

This is what you need:
Get a big air compressor with a 25-60 gallon tank and maybe a 1-2hp
motor.  Turn it on when you leave in the morning, and evacuate it when
you get home.  It'll both push out the warm air, and fill your
apartment with freezing cold air, because when compressed air expands
it cools, like freeze-in-a-can.

snsh----that is a most creative solution.  Thanks for the terrific comment!
ron