Whole House Fan install

[SLC97SR5]

My Father in law, ricsrx introduced me to a whole house fan years ago and I haven't been able to get it off my mind.

There are several styles of WHF's, the one that most are familiar with are the reason I think they are not very common. They are loud, poorly insulated and while very affordable the installs are usually pretty half-assed.

WHF's are in the simplest terms, large exhaust fans that mount in the ceiling or attic and draw fresh, cool air through open windows, and exhaust it into the attic. They are not swamp coolers or attic fans. They pull air from rooms that have makeup air available, ie open windows. They will not do anything for closets or that windowless hallway bathroom.

I had become obsessed with the idea of a WHF because I hate being hot, having a stuffy house and running central air more than necessary. Sure, you can open strategic windows and place a box fan in them (which we did for several years) but it becomes a pain, and makes privacy difficult depending on window coverings.

Our house is a 3300 sqft rambler with slightly deeper than usual eave overhangs and 2x6 walls. It was built in 1983 so it is certainly not as tight as some modern construction but the windows have been replaced with double pane low-E glass and additional insulation added. We face West.

A few months ago I installed a Nest thermostat and started monitoring house temps and humidity. I noticed that as long as the house was pre-cooled or pre-heated it would maintain that initial temperature as long as there wasn't anyone home and the windows and doors remained closed, until about 4pm-ish when the Sun really started hitting the brick and roof. This was a stark contrast from our previous '90's built multi-level starter home. That house ran hot sun-up to sun-down.

I knew that if we were going to actually use a WHF past the novelty stage, it had to be quiet, decently insulated, easy for anyone to use and not ugly. Most important, it had to move some air!

My research led me to Quietcool.com. They are built in USA and have a reasonably long track record in the HVAC world. Most of their units have a 10yr warranty.

 

[SLC97SR5]

Here is a previous posting from another thread:

General Tech - What did you work on Today?

Got my fold down cot beds installed in my enclosed trailer. Im slowly turning it into a shitty camper that hauls both my buggys.

www.rme4x4.com

The install was easy once all the blown-in insulation was cleared from around the area to be cut out for the duct/damper assy.

Most WHF's recommend placing it in a central location especially if that is near a stairwell. I didn't do this for a few reasons.

1-Serviceability, I did not want to hike down to the center of my attic in the event the unit needed attention.
2-Noise, although this unit is very quiet I wanted to make sure it could be used overnight with no impact on sleeping.
3-Kitchen venting, I chose a spot over the man door entrance to the garage, this happens to be just to the side of the attic access and located in the ceiling near the kitchen. I wanted to be able to evacuate cooking fumes and steam without the fan dragging it through the house to the intake grill.
4-Aesthetics, the intake grill for the WHF is a nice looking egg crate style popular in a lot of new construction but if I placed it centrally it would be the first thing seen when entering the house or exiting bedrooms.

I painted the intake duct damper doors with some Hammered brown paint, this made the doors totally disappear behind the grill.

I opted for a wireless controller made by econtrols USA. I really took a chance on this unit since it was in an obscure corner of the Web and I could not find any reviews from folks that had used it. Knock on wood it is working as advertised. However, once I got it setup I wondered "why can't I just use a wireless controller for a ceiling fan?" That would be less expensive and far easier to source. I don't know it they have an amperage limit or why I didn't come across that idea in my research.

No one really talks about wiring in the fan, they only mention the ease of install. The fan comes with a 3 prong pigtail that can be used to simply plug in an outlet or can be hardwired. My buddies and I found a junction box that had power running in it, an outlet later and we had the fan blowing...until I turned off the kitchen lights--oops.

Yesterday my friend came up and we installed a dedicated 20A breaker with a run to the WHF's own duplex outlet.

Things to keep in mind:
1-How large or how many CFM do I need the fan to move? https://www.conservationmart.com/t-whole-house-attic-fan-cfm.aspx
2-Net free attic venting, I do not have enough. My house does not have soffit vents. Only 7 turtles and a larger opening for an attic fan. I'm at about 3 sqft and should be almost 8. That'll be a project for another day.
3-Wiring, I'm a house project idiot so this intimidated me (Of course so did cutting a big ass hole in the ceiling) but I had a very experienced buddy give me a hand.
4-Framing. The Quiet Cool series of fans do not require any framing or joist cutting. They are able to be installed on 16" or 24" OC. This leaves one long edge of the damper box just sitting on the drywall. Because of my inexperience and thinking that drywall is super fragile and ready to break as soon as you touch it, we built a frame spanning the 2 rafters and both of the short sides. This took a little extra time but everything now screws into wood, not drywall.

 

[I Lean]

I like the idea of these. I've never heard anyone say they regretted installing one....

 

[SLC97SR5]

Pics of the install...

 

[SLC97SR5]

The pics are jumbled...posting from the phone.
In short, as long as the outside temp cools to or below your desired inside temp these can be used with great results. I have even cracked a few exterior doors and flipped the fan on prior to turning on the A/C to purge the attic of hot air.

If your house is built tight/insulated and you have some shade during the heat of the day you may be able to get away with cutting 4-10 hours of A/C use daily!

I have noticed some additional humidity in the house. Up to 55%, right after closing it up for the day. I usually run the HVAC blower fan for an hour and it takes it down to 40%. Running the A/C dehumidifies in a hurry.

I'm not sure how useful it will be once Summer is in full swing but for the other months it is well worth it.

A word of caution, a WHF will absolutely extinguish any gas appliance pilot lights if there are not a sufficient amount of doors or windows open. Also, take care that your fireplace flue and doors are closed...wouldn't that be neat to suck all of the fire box ash throughout the house.

 

[Marsh99]

I installed a kitchen hood vent with 750 cfm flow and it vents to the outside. I crack open windows at night and let the hood vent pull the air through the house.

 

[SLC97SR5]

Yep, same principle. I wish an exterior vent for our range hood wasn't such an ordeal.

This unit moves 5024 CFM on high and 4406 CFM on low. I should be seeing 12 air changes per hour on high.

If one wanted to test the WHF theory for super cheap, open up your attic access hatch and place a regular box fan pointing up into the opening. This will at the very least purge hot attic air out of the gable, soffit or ridge vents.
Box fans can move over 3000 cfm but their downfall is being overcome by static pressure so it is unlikely you'd ever see the claimed cfm rating.

 

[frieed]

First thing I did when I bought the house was to put a 24" ceiling exhaust fan in the garage and a screen door from the house to the garage.

 

[pkrfctr]

My friend in Reno had a WHF in his place that was super fancy. It pulled air from the crawl space and had dedicated vents that would open and close with the fan. it was installed when the house was built. He never ran his a/c the thing was awesome.

 

[jeeper]

I was thinking this was a much bigger project and unit. That seems super simple.

When we redid our roof a couple years ago, I pulled the swamp cooler of the roof. The down draft hole is still in the ceiling, and the wiring going up is still there.. I could install one of these in no time!

 

[jeeper]

My research led me to Quietcool.com. They are built in USA and have a reasonably long track record in the HVAC world. Most of their units have a 10yr warranty.

Quietcoolsystems.com is where I found it..

 

[ricsrx]

I was thinking this was a much bigger project and unit. That seems super simple.

When we redid our roof a couple years ago, I pulled the swamp cooler of the roof. The down draft hole is still in the ceiling, and the wiring going up is still there.. I could install one of these in no time!

i also used the old Swamper wiring.

 

[sawtooth4x4]

I had this type of cooling in a townhouse in Wyoming. At night it would actually get cold in the place. We lived next to an irrigated field. It was very nice. Plus the sound of the loud as hell fan knocked me right out. I slept wonderfully.

 

[jeep-N-montero]

We are having a new furnace and central air installed today, this would be a good option for replacing the swamp cooler, or at least swap in a high-output fan in the cooler hole and run it off the cooler temp sensor at night.

 

[I Lean]

I just ordered one of these fans, largely because I have had it on my mind ever since this thread was posted. Thanks a lot.

 

[SLC97SR5]

Awesome! What did you get? We just paid our lowest July and August power bills since 2014. That includes this current house and our previous house that was smaller.

I don't expect it to pay for itself, for me it is about being comfortable but it is nice that it is saving some $$.

We have not used the AC in 7 days.

 

[I Lean]

Awesome! What did you get? We just payed our lowest July and August power bills since 2014. That includes this current house and our previous house that was smaller.

I don't expect it to pay for itself, for me it is about being comfortable but it is nice that it is saving some $$.

We have not used the AC in 7 days.

I just got the 2250 CFM Energy Saver model. It's on the smaller side for what my house should be, but I'm not worried about ventilating the basement or anything. Hopefully I don't regret anything...

 

[Brad J]

I just got the 2250 CFM Energy Saver model. It's on the smaller side for what my house should be, but I'm not worried about ventilating the basement or anything. Hopefully I don't regret anything...

I bought the QC ES-2250 on sale for $712 just days after reading this post in June. I've been opening up our windows and running an Oscillating fan for years to pull cool air in to keep our Central Air happier and Power bill lower. I do wish I went a little bigger even with our smaller 1200 square foot main floor. It works great but I imagine a bigger unit could get the house cooled off faster. We found out that we had a bad mosquito problem after putting ours in. It was pulling them in through the Fresh Air intake in our furnace and water heater closet. I put screen door mesh over the hole and that helped but we then had them coming in somehow through the Fan's Damper Doors during the day. I ended up having to put up Screen Door mesh at the end by the fan in the attic and have not had any problems since. We do live in the swamp so I doubt others will have this same problem. We have Solar Panels so we pay around $10/month regardless but the house is very cool in the morning and the AC doesn't need to kick on till the late afternoon. Our front room and kitchen have vaulted ceilings so it is installed in the hallway between the bedrooms and the bathroom. We're very happy with the purchase.

 

[I Lean]

That's good to know about the mosquitoes. Did you put the mesh on the end of the fan itself?

Edit: What's the shiny stuff against the roof? Do you have insulation up on top there or something? Mine just has nails to catch a shoulder, head, or unsuspecting hand.

 

[SLC97SR5]

Brad, that is an awesome thermometer setup you have.

Is it wireless? Do you have a model or link?