Whole house fan

[supratreo]

Hi, so my brother in law any cousin both just purchased houses with whole house fans and now i think i need one.
had no experience with them before but have been looking and seems like they have some now that are much easier to install as the motors are mounted remotely. theirs are the old style 3x3 or so that has the fan and motor directly mounted to the frame in the opening.

i've been doing some research and it seems like there is some misinformation between companies.
my house is just under 5k sqft, but one site says i need one size (cfm) while another might say i need twice that....
i would much rather get my information here from you guys than some salesman/site.

i'm not looking for hurricane force winds but our weather here in NorCal durring early fall and spring is very nice and i would like to enjoy that VS air conditioning.
only requirement i might have is that i would need a remote way to control it as it mainly needs to be controlled from downstairs.

last concern is that i have my furnace/air handler and tankless WH in the attic space. would the fan affect their operation? i'm pretty sure the WH is sealed besides the intake vent.
i havent done any type of calculations but i have vents all around the house and also 2 powered vents on the roof.
sorry for the long read.

 

[nadogail]

Unfortunately, the only opinion I have to offer is “It Depends”.

 

[supratreo]

what about good, fast and cheap?

 

[nadogail]

Good, Fast and Cheap are the options I offer to my clients, they are allowed to pick any two; but not all three.

 

[walta]

They are great this time of the year when it is cool at night and warm in the day.

From an energy point of view in most climates there are few days when they will be useful and many more days when you are running the AC or furnace and the fan is a huge uninsulated hole in your ceiling venting your conditioned air out of your house and into your vented attic.

There are a few fans with insulated motorized doors but seems to me they are smaller and move much less air.



Walta

 

[tool_scrounge]

In Southern California, where it can be hot during the day and cool at night, fans like that can work well to cool off the house in the evenings before going to bed. Some folks have recycled squirrel cage furnace fans in their garages to blow hot air & fumes out a garage vent. If you have one of these fans and an attached garage, you can open the door between the garage and the house about a foot and the fan will **** the hot air out of the house. Just open the far windows in the house first. It is a "Poor man's whole house fan".

 

[Max]

Hi, so my brother in law any cousin both just purchased houses with whole house fans and now i think i need one.
had no experience with them before but have been looking and seems like they have some now that are much easier to install as the motors are mounted remotely. theirs are the old style 3x3 or so that has the fan and motor directly mounted to the frame in the opening.

i've been doing some research and it seems like there is some misinformation between companies.
my house is just under 5k sqft, but one site says i need one size (cfm) while another might say i need twice that....
i would much rather get my information here from you guys than some salesman/site.

i'm not looking for hurricane force winds but our weather here in NorCal durring early fall and spring is very nice and i would like to enjoy that VS air conditioning.
only requirement i might have is that i would need a remote way to control it as it mainly needs to be controlled from downstairs.

last concern is that i have my furnace/air handler and tankless WH in the attic space. would the fan affect their operation? i'm pretty sure the WH is sealed besides the intake vent.
i havent done any type of calculations but i have vents all around the house and also 2 powered vents on the roof.
sorry for the long read.

Whole house fans are a great solution when it’s hot during the day but much cooler at night. When you run one, not only does it bring in cool air through the windows it also uses the relatively cooler house air to cool off the attic as well. I installed one when we lived in the SF Bay Area and it was great as we only had to use the AC for a couple of weeks a year. And obviously a fan uses a lot less electricity than a fan + condenser + compressor.

Ours was 3’. To minimize framing work I built it in a box above the ceiling joists but only two joists wide. Being 3’, it was noisy when running. A friend had a 4’ or 5’ one that was a lot more work to install, but it spun so slowly that he could keep it running on slow when slept. Ours was too noisy for that. Both fans had louvers on the ceiling that would lift up automatically when the fan started.

I don’t think that the CFM is critical. Obviously a higher CFM fan will move more air, but you will see a good benefit if the fan is smaller - it will just take longer to get the same cooling. I’d prioritize fan size/noise over raw CFM myself.

 

[David Paul]

Check out Quitecool. I just installed one in our home here in NJ. Couldn’t be happier. Biggest issue is to make sure you have enough venting in attic for the air to get out. Not sure of the affect on other appliances in the attic.

 

[kbuhagiar]

Hi, so my brother in law any cousin both just purchased houses with whole house fans and now i think i need one.
had no experience with them before but have been looking and seems like they have some now that are much easier to install as the motors are mounted remotely. theirs are the old style 3x3 or so that has the fan and motor directly mounted to the frame in the opening.

i've been doing some research and it seems like there is some misinformation between companies.
my house is just under 5k sqft, but one site says i need one size (cfm) while another might say i need twice that....
i would much rather get my information here from you guys than some salesman/site.

i'm not looking for hurricane force winds but our weather here in NorCal durring early fall and spring is very nice and i would like to enjoy that VS air conditioning.
only requirement i might have is that i would need a remote way to control it as it mainly needs to be controlled from downstairs.

last concern is that i have my furnace/air handler and tankless WH in the attic space. would the fan affect their operation? i'm pretty sure the WH is sealed besides the intake vent.
i havent done any type of calculations but i have vents all around the house and also 2 powered vents on the roof.
sorry for the long read.

We have a 3200Sf home in Escondido, CA and we installed two Solatube whole house fans (Model 3000VS, 2500cfm each), one at each end of the house. We are extremely happy with the results. Each fan has a six-speed wireless control and it allows us to drastically reduce the use of the AC in the spring and autumn.

Whole House Fan Models - Solatube Home Products

Take a look into the specs and other features of our Whole House Fan models. Solatube Home is known for their amazing product innovations.

solatubehome.com

Although they are controlled wirelessly they cannot be programmed remotely and/or to turn on and off on schedule; I'm trying to find an aftermarket solution for that.

Our HVAC air handlers (two of them) are also located in our attic space and the fans have no effect whatsoever on their operation.

Good luck!

 

[kaymccampbell]

I have the fan unit and some of the case from a dead gas furnace installed in the attic to provide whole house venting. It works great. It will change the air in the house in maybe 10-15 minutes. The biggest cost was the flex duct to get through the insulation, and the timer switch to control the fan.

 

[driftpin]

I have one of the motor inside the fan frame models, guessing it's ~ 30." N.I.B. No need for it. I thought of using it as a garage fan (2-car) but it's really bigger than I need, and would probably just be in the way. They were very popular in Florida houses up into the 1950's, friends had 'em and they did a good job of moving air.

 

[ChefRex]

Growing up we had a WHF in the third floor, worked well except for the hottest of days.

 

[Innovate1]

They were pretty standard here in the midwest long ago. We put one in when we built. The traditional ones, which are still available at the big box stores here are about 30" and have a slightly larger square frame. They are built to straddle a ceiling joist so will work with 24" and I think 16" framing. I built a tall box around ours - it keeps the insulation from falling into the fan and allows a hinged insulated lid to be put on top. I close the lid in the winter - a remote controlled motor to open and close would be great. Might rig something up as I am getting older... I watch the humidity - actually dew point - and when it will be below about 60 at night we run the fan. Then close things up in the morning. You need to open several windows as they move a huge amount of air. You also need to ensure you have enough vent area so air can leave the attic.

 

[supratreo]

i appreciate everyones input. i did consider the issue with it being a huge space that will loose heating and cooling. i did see a couple that had built in dampers but i'm sure that also add quite a bit to the cost. i'm going to go through all of this before i make a decision. i just hate hearing the AC come on this time of year when we have the doors open to try to get the nice cool air in. going to also have to make a few more adjustments to my smart thermostat so the ac stay off i guess.

 

[rharman]

Our experience was that the whole house fan sucked in a TON of dirt/dust from the outside . We got rid of it for that reason. Fan was in upstairs attic access so the dust came up through, essentially, the "whole house".

 

[Shiftless]

Our experience was that the whole house fan sucked in a TON of dirt/dust from the outside . We got rid of it for that reason. Fan was in upstairs attic access so the dust came up through, essentially, the "whole house".

This is probably the biggest concern. I put in a WHF almost 30 years ago and consider it one of the best home improvements I have done. Most hot days here are followed by cool evenings so the fan pulls in nice cooler air and flushes out the stale hot air in the house and cools the attic too. It’s vital that you have enough vent area in the attic, I added some with the install. My house is single story about 2000 sq. ft. The 30 inch WHF has a quiet 2 speed Dayton belt drive motor that pulls maybe 6000 cu.ft./minute on high. That takes care of business. On low, maybe half of that but you can barely hear it run from 20 feet away. I mounted it in the hallway ceiling near the center of the house. Fortunately, in the afternoon I can open the windows above the walk out basement and get very clean air.

 

[67carl]

Whole house fans are a great solution when it’s hot during the day but much cooler at night. When you run one, not only does it bring in cool air through the windows it also uses the relatively cooler house air to cool off the attic as well. I installed one when we lived in the SF Bay Area and it was great as we only had to use the AC for a couple of weeks a year. And obviously a fan uses a lot less electricity than a fan + condenser + compressor.

Ours was 3’. To minimize framing work I built it in a box above the ceiling joists but only two joists wide. Being 3’, it was noisy when running. A friend had a 4’ or 5’ one that was a lot more work to install, but it spun so slowly that he could keep it running on slow when slept. Ours was too noisy for that. Both fans had louvers on the ceiling that would lift up automatically when the fan started.

I don’t think that the CFM is critical. Obviously a higher CFM fan will move more air, but you will see a good benefit if the fan is smaller - it will just take longer to get the same cooling. I’d prioritize fan size/noise over raw CFM myself.

Check out Quitecool. I just installed one in our home here in NJ. Couldn’t be happier. Biggest issue is to make sure you have enough venting in attic for the air to get out. Not sure of the affect on other appliances in the attic.

After reading the OPs first post these ^^ were the things that I thought of. I built a box and set it on the joists as Max did in a central hallway. CFM is not that important, as you can open select windows at different points downstairs and adjust how much they are open to manage the airflow, depending on your floor plan.

I will say it is loud, but as David Paul said there is Quiet Cool. I looked at those but thought they were too expensive. If I were to do it again I think I could build something similar for a lot less.

btw; I'm your neighbor to the north - Arden Arcade. The fans help out a lot when the Delta breeze is blowing, or you get overzealous with cooking an need to evacuate smoky air quickly!

 

[Max]

After reading the OPs first post these ^^ were the things that I thought of. I built a box and set it on the joists as Max did in a central hallway. CFM is not that important, as you can open select windows at different points downstairs and adjust how much they are open to manage the airflow, depending on your floor plan.

I will say it is loud, but as David Paul said there is Quiet Cool. I looked at those but thought they were too expensive. If I were to do it again I think I could build something similar for a lot less.

btw; I'm your neighbor to the north - Arden Arcade. The fans help out a lot when the Delta breeze is blowing, or you get overzealous with cooking an need to evacuate smoky air quickly!

Whole house fans are awesome in the right climate. Way less power than an AC and they cool off the whole house. The only down sides are noise for a cheaper one, maybe a bit more dust, and obviously not so good if you're dealing with CA smoke/fires. We had issues with skunks occasionally, but lightng a candle would get rid of the smell quickly.

 

[scoob8000]

Many years ago when we were house hunting we looked at a house that had a fan. It was hot as hell in the house, but then the agent turned the fan on (windows were already open). I was so amazed at how much air it brought in, I installed one within the first year in our house.

Install wasn't too bad, but I have a fully accessable walk up attic and just lucked into having the perfect spot to mount it.

This is the exact unit I have. I have the 24" belt driven model. https://www.amazon.com/gp/product/B002TXEC3W/?tag=atomicindus08-20
If you want to be mad at inflation, I paid $184 for it in 2011.

I mostly use it in the evenings when it's cooler outside to pull that cool air in. Make sure your windows are open, if not it will **** the pilot light out in your water heater.

 

[infinkc]

i appreciate everyones input. i did consider the issue with it being a huge space that will loose heating and cooling. i did see a couple that had built in dampers but i'm sure that also add quite a bit to the cost. i'm going to go through all of this before i make a decision. i just hate hearing the AC come on this time of year when we have the doors open to try to get the nice cool air in. going to also have to make a few more adjustments to my smart thermostat so the ac stay off i guess.

Hey see you are from EG, fellow EG member here also.

We have 2 Quiet cool units in our house, also just under 5k sqft. Our contractor said it needed 2 cause the size and also being 1 story. The 2 units do pull a lot of air, nut think we could have gotten away with 1 unit. My brother also has 1 unit in his home in the area also on a 2 story, it works great. He opens the down stairs first, then when that cools opens the upstairs.

They are really quiet compared to the old style where the fan is on the ceiling grates.

They do work well this time of year here.

Home depot sells them at a good price.

 

[67carl]

...I mostly use it in the evenings when it's cooler outside to pull that cool air in. Make sure your windows are open, if not it will **** the pilot light out in your water heater.

Or, if you have a fireplace, it will pull air down the chimney into your house along with ashes. Ask me how I know

 

[steel 35]

I have one in place of a bathroom fan spare 1/2 bath next to the attached Garage, so I can pull air through the house ; Garage or both.
it's Dirty for sure, moves the air.
I always joke don't pee with the fan on, it'l get ya

 

[supratreo]

Hey see you are from EG, fellow EG member here also.

We have 2 Quiet cool units in our house, also just under 5k sqft. Our contractor said it needed 2 cause the size and also being 1 story. The 2 units do pull a lot of air, nut think we could have gotten away with 1 unit. My brother also has 1 unit in his home in the area also on a 2 story, it works great. He opens the down stairs first, then when that cools opens the upstairs.

They are really quiet compared to the old style where the fan is on the ceiling grates.

They do work well this time of year here.

Home depot sells them at a good price.

big help. thank you.
do you know what model you have? i feel like i'll be fine with 1 also.