Any solar users in SoCal also using a whole house fan?

[sdold]

The only watchout is that you don't want your fan to turn on automatically (based on a thermostat) because exterior windows need to be open to avoid concentrating CO and other gases from gas-fired appliances or operating fireplaces.

Great point. Even a non-operating fireplace can be a problem, I'll never forget the mess of ashes all over the living room carpet after I turned the fan on with the windows closed and the fireplace damper open. It was a good thing there was no fire going!

[donald]

The only watchout is that you don't want your fan to turn on automatically (based on a thermostat) because exterior windows need to be open to avoid concentrating CO and other gases from gas-fired appliances or operating fireplaces.

Shutting it off is a great idea. The fan I am installing has run-time options that automatically shut down after a preset time but the auto-shutoff when temp is reached option would be nice. I guess the other thing to mention about that is that, although the desired air temp is reached, you might want to continue to run the fan to ensure you are pulling "remaining heat" of your house's mass so it doesn't rewarm.

I agree on both points. A fan like this, installed attached to an automatic system, also needs a service switch and a warning label. Even if the design intent is to never auto start, the capability to auto start is part of the zwave power switch.

Usually the fan should not turn off when a comfortable temperature is reached. It should turn off at the minimum acceptable temperature.

A long time ago the fan ran all night when the outside temperatures went down to the 50's (F) overnight. Much complaining ensued that morning.

Oh, another device that turns off all fans are my smoke alarms. My smoke alarms wirelessly report to my home automation controller. I also get a text to my phone indicating which smoke alarm has triggered. Lights are also turned on, and a few lights are turned red to indicate alarm type (These lights will turn blue to indicate water alarm). If my basement smoke triggers I also shut of some additional equipment.

A lot of people could have saved their pet had they simply received a text message that a smoke alarm has triggered.

[TypeRx]

The only watchout is that you don't want your fan to turn on automatically (based on a thermostat) because exterior windows need to be open to avoid concentrating CO and other gases from gas-fired appliances or operating fireplaces.

Shutting it off is a great idea. The fan I am installing has run-time options that automatically shut down after a preset time but the auto-shutoff when temp is reached option would be nice. I guess the other thing to mention about that is that, although the desired air temp is reached, you might want to continue to run the fan to ensure you are pulling "remaining heat" of your house's mass so it doesn't rewarm.

[jd31]

The brand of fan doesn't matter. I have a home automation controller (vera) that controls a variety of z-wave devices. So I just added a zwave switch to the fan power supply. My thermostats are all zwave enabled (there are many brands). So when the temp drops the controller turns off power to the fan.

The controller also gets forecast and actual information from Weather Underground. So I built rules to make the fan turn off at night if rain is near.

These types of systems also also allow smart phone control of all types of connected devices. So if I want to turn off the fan (or turn on the AC) in the middle of the night I can just pick up my iphone.

For anyone with a bit of software skills it makes a lot of sense to build up a generic zwave/zigbee system rather than buying specialized stand alone control devices.

Thank you for this! Very helpful. I'll look into this technology; very cool features.

[donald]

That's a neat feature (thermostat integration). What type of fan do you have and was it designed to integrate with your thermostat?

The brand of fan doesn't matter. I have a home automation controller (vera) that controls a variety of z-wave devices. So I just added a zwave switch to the fan power supply. My thermostats are all zwave enabled (there are many brands). So when the temp drops the controller turns off power to the fan.

The controller also gets forecast and actual information from Weather Underground. So I built rules to make the fan turn off at night if rain is near.

These types of systems also also allow smart phone control of all types of connected devices. So if I want to turn off the fan (or turn on the AC) in the middle of the night I can just pick up my iphone.

For anyone with a bit of software skills it makes a lot of sense to build up a generic zwave/zigbee system rather than buying specialized stand alone control devices.

[jd31]

Whole house fans are wonderful for areas that cool off at night. It's more than just an energy savings choice. It's an air quality choice. Be sure to at least get a timer.

Mine turns off based on temp by reading the upstairs HVAC thermostat. It also turns off when rain approaches.

That's a neat feature (thermostat integration). What type of fan do you have and was it designed to integrate with your thermostat?

[J.P.M.]

Geez is that what they call Attic Fans now. Damn marketers.

Different purposes.

[sdold]

I think attic fan refers to the fans that are on the roof or gable and cool the attic by pulling air in through the gable and soffit vents and blowing it out.

[Sunking]

Geez is that what they call Attic Fans now. Damn marketers.

[Mike90250]

I cut a plywood sheet to fit my ceiling attic hatch, and suspended a 20" box fan (via bungee cords) to exhaust house air into the attic and then let the attic vents disperse the air. Worked quite well, any room with an open window, had a cool breeze coming in.

[sdold]

We love ours. After a hot day, it's like having a cool breeze blowing through every window. Be sure to get a slower-turning quiet one with belt drive vs. a direct drive one with a higher fan speed. Triangle is a good brand.

[donald]

Whole house fans are wonderful for areas that cool off at night. It's more than just an energy savings choice. It's an air quality choice. Be sure to at least get a timer.

Mine turns off based on temp by reading the upstairs HVAC thermostat. It also turns off when rain approaches.

[jonathan]

(Revised after a moderator pointed out I shouldn't have a direct link to gear -- oops, my mistake, sorry.)

We have an AirScape fan. It has an ECM motor, so it's efficient, and virtually silent for 5 of the seven 7 speed settings. We love it. We're in the bay area, and have elected to skip A/C since our house is fairly efficient, and there are only a few days over the summer where it's hot enough to consider using it during the day. With the whole house fan, we can pre-cool at night, as well as replace the interior air with fresh air.

[bcroe]

The fan is $1300 and there are currently no rebates/incentives where I live
(Orange County). I'll install myself, so that saves a few bucks but just wondering if others here
see value in a whole house fan vs. just using A/C when you are solar powered. Thanks!

Solar energy is only "free" when the solar is already paid for. Still at that point, it is nice to
just turn on what you want and see the meter continue to export your surplus. Bruce Roe

[kylechoffman]

I am looking at putting two of these in due to the setup of my attic and spread-out nature of my 2nd floor: http://www.centricair.com/whole-hous...entricair-3-1/

The one you mentioned is cheaper than two of the ones Im considering but adding in the two speed control brings the cost above 1400. The estimate I received was 2K installed. I think they are a good idea to offset the usage in the evenings.