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

[TypeRx]

any installer/system in Socal area/Orange County? Pm me.

Look at my original post in this thread. I purchased my fan locally (south orange county) and installed it this weekend myself. They will install for you if you want. I am mildly handy (at best). Works great..looking forward to see how well it performs as the heat rolls in this week.

[SunEagle]

Partly, but mostly its a cost thing. Obviously, direct drives don't have the belt/gear/etc. losses and thus have lower power requirements = smaller motors & lower op. costs. Lower speeds need large dia./areas for same vol. of air movement. Lower speed -> less noise, but bigger fan area, more mechanical losses and higher mfg./maint. cost. Quieter operation is sure nice but it's the no free lunch thing.

A bigger and slower "fan" seems to be the direction the large wind turbine are going. The original ones were in the 100 kW size. Now they are taller and about 3 MegaWatts.

[J.P.M.]

I've noticed this, the slower fans with the big blades seem much quieter. These are usually belt-driven. Do you think they need to use faster-turning fans with direct drive because the motors need to turn at a higher speed?

Partly, but mostly its a cost thing. Obviously, direct drives don't have the belt/gear/etc. losses and thus have lower power requirements = smaller motors & lower op. costs. Lower speeds need large dia./areas for same vol. of air movement. Lower speed -> less noise, but bigger fan area, more mechanical losses and higher mfg./maint. cost. Quieter operation is sure nice but it's the no free lunch thing.

[bcroe]

I've noticed this, the slower fans with the big blades seem much quieter. These are usually belt-driven. Do you think they need to use faster-turning fans with direct drive because the motors need to turn at a higher speed?

That is pretty much how it is, bigger & slower is quieter. Becomes obvious if you design enough
electronic equipment. Variable speed fans help a lot. Work to reduce fan noise includes that
uneven spacing of my car radiator fan blades, spiral center supports, and interesting asymmetric
blade shapes. The centrifugal fan in your furnace is generally a quieter design than an axial flow.
I built quite a few speed controlled fan systems. Bruce Roe

[silversaver]

any installer/system in Socal area/Orange County? Pm me.

[sdold]

Fan tip speed is where the noise comes from - low tip speed is what you want

I've noticed this, the slower fans with the big blades seem much quieter. These are usually belt-driven. Do you think they need to use faster-turning fans with direct drive because the motors need to turn at a higher speed?

[russ]

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.

Fan tip speed is where the noise comes from - low tip speed is what you want

[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.

[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.

[kylechoffman]

Has anyone here used quiet cool fans?

[sdold]

Just google both and see what you come up with.

[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!

[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.

[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.

[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.