Whole House Fans and the Central Valley

I have been in pursuit of a whole house fan for almost a year.

My coffee drinking buddy had two installed in his house over a year ago.  But his house has got more square feet than ours by quite a bit.

My mother and father-in-law had one in their Ft Collins, Colorado home.  It replaced the ubiquitous 20 inch fans they brought out each evening to eat dinner beside and watch the news. They worked reasonably well  and my wife was completely sold for them in the Colorado climate. Their temperature, a good dry heat most of the time was completely abrogated by the afternoon cloud cover and the by 3:30 there was no more build up to the heat and most  people endured their summer weather without air conditioning. The whole house fan was installed to reduce the evening heat build up in the attic and to draw cool air in from the windows especially when it came time to bed time. The 20 inch fans worked wonders in drawing cool air into the living spaces and making the evenings pleasant indoors but they failed to address the issue of very hot attics that returned the heat to the living space after the fans were turned off.  My mother and father-in-law would have the whole house fan work just an hour or two and summer evening and could come indoors away from the pesky mosquitoes that tortured outdoor living.  

The central valley summer night heat is another animal. Our heat generally continues to fire through the afternoon and into the evening until the sun goes down.  Then in a couple of hours 10 to 15 degrees are dropped out of the 90 plus degree temperatures reaching our coolest temperature about 2 am sometimes in the 60's. From 11am through to the evening we live under the air and the the attic even though vented with 3 turbines and end cap releases still harbor air most of the night. Our "cool" water at the sink doesn't get cool without running quite a bit of it as the attic temperature heats the copper pipes as the water makes it way to the various spots it is used in the house.

So how would a whole house fan work in that environment? Using outside air that is warmer than what you have cool using air conditioning doesn't make sense. Our inside air is set at 78 degrees. The air needs to be below that temperature to be affective. The use of the whole house fan before 9 am is when the most effective use of the fan is noted.  On many weeks we have days that the temperature does not reach 90 degrees. Those days can be very effective for evening use of the fan.

The fan takes the outside air from windows that are opened and doors that are opened and shoots the indoor air up into the attic and eventually in less than 30 minutes the outside air into the attic too. The house stays cooler longer with realistic attic temperatures. Windows need to opened to allow the air to come inside. The wider the window is opened the more air flows into the room. At least 3 windows need to opened or the fan could crack your windows.

This year at the fair there was vendor that was selling the fan and installation. They would provide a 300 dollar discount if you signed up at the fair. They had a booth at the Merced county fair but Sue wasn't with me when I went in to find out the particulars. So it got set aside. At the Stanislaus County Fair they were there too.  Sue was with me and we signed up. One week later and 1600 dollars later it was installed in our main hall.

A member of the two man install team crawled up into my attic at 7:30 am.  He pulled away from the attic floor the insulation and sunk four holes into my ceiling wallboard with nails. From those four nails, after carefully measuring from down below, a saws-all type saw cut the hole that they mounted the frame for the louvers. Out in the front 2x6 wooden framing was fabricated and lifted into place and supported by my ceiling truss. The fan was positioned and and secured in place. Electrical was found and attached to the dead doorbell connection. The wall mounted control area was located just under the programmable thermostat. No exposed wires were needed. It also came with a thin remote control. The louvers were installed on the outside of the frame and a stopper peg was installed so that the louvers would not stay open. A quick run through and check was made of the remote and the various positions on the device. The two guys brought in a power vac and cleaned up after themselves and were out the door with my check in hand in just under 2 hours. 

Sue was not too happy about where it was installed.  She thinks that she will end up staring at from the living room way too often.  I reminded her that she could have had a say in where it was going to be but opted out.  That didn't win me any friends. She thinks that she will get used to its location eventually.

Right now we are using it almost every night to get the house under its 78 degree cooling temp. Most nights it can drop the temperature in the house to under 72 degrees... as far as comfort ... it is yummy. Yesterday was the first night that we did not use it.  The outside temperature did not drop to under 78 until after 2:30.  We kind of missed out cool breeze. It still worked pretty nicely when I fired it up this morning at 7:00 and shut it down to let the air conditioning take its place at 10:30.

The company works out of Sacramento and Fresno sending installation teams all over the valley. The installer said that he had put in over 200 of them last year. This year he seems to be doing more. The Sacramento team was doing about the same.