So I know that I ask alot of questions on here about my house, but I have gotten some good answers from members/vendors on here.
I own a cape style home built in the mid 50’s that had the upstairs refinished after a fire in 1994.
Long story short, the ventilation in the knee wall crawl space isn’t very good. There are 2 small gable vents on either side of both crawl spaces. No ridge vent or soffits.
I was going to put soffits in, but the original roof line ended flush at the sidewall leaving no room for them.
The problem is, I live in the a tight area where the houses are stacked right next to each other and the gable vents really don’t get much air flow.
I have done so much research on how to get some ventilation in there without spending ridiculous amounts of money.
Which leads me to this:
Has anyone installed this or have one and can tell me how beneficial they are? I know that a combo of ridge vent/soffit is the best design out there, but I have no way of doing that. This seems to be my best option right now.
Any ventilation you attempt is going to be beneficial, for both the summer and winter months. If you have gable end vents that should allow for air flow in and up out the rotating vent. Ridge and soffit vents are always a good thing but 99 % of capes just don’t have the capacity for that setup, at least not when they were built.
The problem with just adding a turbine, with no soffits or eave vents, is you’re still not going to draw the air from the right places. That turbine is going to draw air out and the only place you have to draw the air in is your gable vents. That’s better than what you have going on now but ideally you’d have your in air coming from the lowest point possible with soffit and eave vents so the airflow to the turbine would actually exchange all the air in the attic.
People take the whole “you can’t have too much ventilation” thing the wrong way and mix multiple ventilation solutions causing more problems than solutions.
EX, when you see a house with a ridge vent plus a turbine or powered attic fan on the gable. The turbine or attic fan will draw air from the point of least resistance, which in that case would be the ridge vent meaning you’re only moving air over a tiny part of the attic.
I have seen that putting a ridge vent in with gable vents only, it actually reverses the process and sometimes causes rain/snow to to be pulled in the ridge and cause leaks to a finished ceiling.
Also, i do have baffles coming down from the upper attic space above my finished room. They run to to the top of the finished wall in the bottom attic area.
If the whirlybird vents were installed up in the top area, would it pull air through the baffles or is that not really a factor?
Also, I should be clear that the gable vents are installed on the floor of the crawl space. Is that still considered to be the lowest part of the attic?
Perhaps I should’ve clarified. The ideal situation would be to have a convective flow of air from the eave to the ridge, circulating in cool or ambient air and exhausting hot air out the ridge vent. Most capes have no soffit to start the upward flow, and most were insulated from the knee wall up the rake of the roof line to the small remaining unfinished space, thus cutting off any possibility for that flow to occur. I would venture that if your gable vents weren’t doing an adequate job, perhaps the rotating vent could “draw” the cooler air through the gables and out. I guess with your situation that there’s no available air to be “pulled” through the baffles to the upper space. I’m not saying none would flow, but I would have to speculate it would be minimal at best.
I’m not sure what you’re referring to with regard to the allowance of water and snow through a ridge vent in combination with gable vents. My own home has both soffit and gable vents, simply because they were there when I bought the house, and the addition of a ridge vent caused no issues. The style I install uses a “mesh” system which stops blown rain and snow from being able to penetrate through. I’m not talking hurricane situations, but it’s endured many storms over the years.
That is what I was hoping I could do myself, but through my research someone mentioned they had problems when using a ridge vent with just gables, no soffits. He said that when the wind picked up, the wind would actually get sucked out the gable vent (as it should), but then the airflow started coming back in through the ridge because there were no soffits to let new air in for the exchange and that is where the suction pulled in rain and snow.
I am under the assumption that you can use either gables or soffit/ridge for the most effective ventilation.
Do you think a ridge vent would be effective without soffits?
It might not have caused any specific issues but everything I’ve read (and it’s a lot because I’m doing a roof where I’ll be adding a ridge vent soon) suggests your current home’s ventilation would work a lot better if you sealed up those gable vents.
In my case I’ve got a raised ranch that isn’t venting properly. On the front of the house there is a good sized overhang with large eave vents but on the back side of the house the roof comes down even with the side of the house not allowing for any intake venting. There is a gable vent on the south end and a powered attic fan on the north end and 4 large roof vents. There is also a roof turbine mounted close to the top near center on the western side taking advantage of the prevailing SE winds.
When I re-do the roof the roof vents and turbine will be going away. I’m going to disconnect the gable fan and add ducting to direct the air coming into the two gables down low in the attic. Any air that gets drawn in or blown into the gables will just continue on it’s convection driven path up to the ridge vent. On the back side I’m considering installing an Smart Vent since adding a soffit vent will be impossible.
Yes, I did use a product similar to that years ago when I had an addition with vaulted ceilings and the design would not allow for vented eaves. Solves that “overhangless” problem.
I too saw this in research, but I figured since my roof is fairly new, I would hate to have to tear part of it off to install that. I guess cutting a hole in my roof isn’t much better either…
