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

[J.P.M.]

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

Different purposes.

[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?

[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]

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.

[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.

[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.

[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!

[slopoke]

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.

Also, if no windows are open and the fan kicks on. If the motor overheats because it's trying to move air but no air coming from an open window, there is a potential for fire. Fire not good.

[Sunking]

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.

You must be a youngster. Attic fans are a big fan installed somewhere centrally located in your house typically a hallway on the ceiling. You open windows, turn it on and it draws outside air into your home through the open windows and exhaust through your attic. Really useful as a kid when Mom and Dad were out and you could smoke inside and no one would ever know.

[jd31]

You must be a youngster. Attic fans are a big fan installed somewhere centrally located in your house typically a hallway on the ceiling. You open windows, turn it on and it draws outside air into your home through the open windows and exhaust through your attic. Really useful as a kid when Mom and Dad were out and you could smoke inside and no one would ever know.

An attic fan and whole house fan are different things. An attic fan is installed in the attic and pushes air outside to cool down the attic. A whole house fan is what you described above.

[TypeRx]

An attic fan and whole house fan are different things. An attic fan is installed in the attic and pushes air outside to cool down the attic. A whole house fan is what you described above.

LOL..funny thing is I am not sure there is fixed nomenclature on this.

Powered attic ventilator = definitely an fan that simply pushes air from the attic through the vents
Whole house fan (old school "attic fan") = a fan installed in between the living quarters and attic space with the intent of using outside air to pressurize the attic, allowing air to exit through attic vents.

Regardless, I think we are all talking about the same thing!

[sdold]

Just google both and see what you come up with.

[kylechoffman]

Has anyone here used quiet cool fans?

[jd31]

Has anyone here used quiet cool fans?

Friends and family have them. Pros: quiet, easy installation, flexible in terms of where you can install them. Cons: more expensive compared to other alternatives.

In my previous house I installed one from Home Depot (~$300 and some elbow grease). Worked great. In my current home I hired a company to install one (small attic so I left it to the pros). They use a 6 blade model that apparently cuts down on the noise. Nice unit. Paid $1,699 installed.

[J.P.M.]

Fact is, when properly sized, installed and operated correctly, whole house fans or whatever name you put on them can remove a fair amount of heat from a dwelling without resorting to mechanical refrigeration. They cannot do the whole job in very hot and/or humid climates, but they can put a substantial dent in an electric bill by reducing or eliminating A/C run times for a substantial portion of a cooling season. They do work.