Whole House Fans

GEARARD IN MURIETTA WITH A BREEZE ON A STILL DAY IN 2014

You might know that whole house fans have been around for 120 years. They were the only way to cool homes before Carrier invented air conditioning. For the first 100 years they were big propellers mounted behind shutters in the ceiling. Most of these were noisy but VERY effective at pulling air. The largest ones – 4 foot diameter blades – pull 14,500 cubic feet of air per minute (CFM).

Then the modern rafter mounted systems were invented. While very quiet, these don’t pull as much air – the best pull just over 5000 CFM. The largest blades used in these is now 24 inches. That is because they depend on flexible duct to connect to the ceiling and larger duct is not made today (May 19, 2019). 

Until 2016 homeowners without attics could not install a whole house fan. Then Kurt Shafer invented the first high flow rooftop mounted whole house fan. See http://thorwaldsonwholehousefans.com/rooftopwholehousefan/