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-   -   Can I replace the Whirlybird Turbine Vent on the Roof with something else? (

Cinderella 08-14-2011 02:24 PM

Can I replace the Whirlybird Turbine Vent on the Roof with something else?
I have two large WhirlyBird Turbine vents on my roof. I live in South Florida. I understand they are there for energy purposes to pull the hot air out of my attic and cut down on the electric bill. But, living in a hurricane area, I would like to find out if I can take them off for hurricane season, close up the holes with the covers and then consider replacing these with something a whole lot smaller and quieter. I do not want to have to worry about these turbines anymore. Will anything happen to my attic if this ventilation is not there for 3 or 4 months? Thanks

RocLok 08-14-2011 03:38 PM

OK, I will take a stab at this, I have been to Florida but do not live there or understand everything about the climate.

So my thoughts are that you do want to seal up an attic especially in a hurricane I would think by sealing it up the pressure difference between the inside of the attic and outside would cause problems. Or that is what I remember from shows about hurricanes or tornados. That is all I know.

oldognewtrick 08-14-2011 05:15 PM

Cinderella, you do not want to totally eliminate the exhaust ventilation. It's there for a purpose. I would suggest using a power roof ventilator with a humidistat control or shingle over ridge vent IF you have sufficient ridge run to support it. Ventilation helps dissipate heat and allows for moist air to evacuate the attic area.

High concetration of heat can cause damage to structure and effect energy bills.

OH, and :welcome: to House Repair Talk

Cinderella 08-14-2011 07:52 PM

Thanks for your responses! I know that during a hurricane I have to take the whirlybirds off the roof and cover the opening. But removing them at the first sign of a storm, putting them back up three days later, removing them during the next scare, putting them back up a few days later is exhausting, expensive and I kinda get tired of begging people to go on my roof to help me. I am looking for something that I do not need to remove or wonder if leaving the whirlybirds off for 3 months is a problem. From what you say Olddog that is a problem. It sounds like a power roof ventilator with a humidistat control or shingle over ridge vent - are expensive. It does sound like they are permanent which is exactly what I am looking for. I do have all those small vents about 40 of them around the house near the fachia board area, but I am assuming that is not enough ventilation. I will investigate the other two options you provided. Thanks!!

gatorfan 08-15-2011 08:03 AM

I just did some research on this myself, and there are a lot of opinions that mechanical roof ventilation (including whirlybird) is not good as it can depressurize the attic and draw conditioned air from the home. The general recommendation seems to be soffit vents and either ridge vents or basic box vents which use natural convection only. If you have enough of them, this should be sufficient to keep the attic ventilated w/o needing mechanical systems.

If you can afford it, conditioning the attic (seal up vents and use spray foam on the bottom of the roof deck) has a lot of fans and it's definitely the best way to waterproof, but I've read conflicting opinions on whether it's cost effective, especially due to the high cost of closed-cell, spray-on insulation.


Cinderella 08-15-2011 08:37 PM

Hello Gatorfan! I have about 40 maybe more soffit vents (they are metal round openings with grated slots to let the air in)around the outside edge of the house going all around the roof a few inches inward from the fachia board area. Knowing nothing about attics and roofs, I wonder what they ventilate if I needed two big whirlybirds as well. Unless they let air in and the whirlybird take the air out (and AC as well, possibly) Of course I have had roofers tell me they have actually seen moss growing in people's attics and wood rot from insufficient ventilation. I do not want that to happen. Since my house is the only one with these birds, the previous owners were smarter than everyone else in the neighborhood or everyone replaced them with something else. I do not know anything about the closed cell spray insulation. I will check that out. I am aware I do not have much insulation in the attic. Thanks! Lots to figure out, here.

nealtw 08-15-2011 09:31 PM

Insulated roofs is whole different thing. The system you have is, as the air heats up in the attic it escapes out the top vents and is replaced be cooler air from the soffit vents. I think any flat roof vent of the same size as a turbine will do just as good.
Do you have to close all vents for a storm down there?

Cinderella 08-16-2011 06:21 PM

Hi nealtw, I guess you can see why I would be a bit confused here. I am finally learning what the soffits do in relationship to the turbine. You have stated exactly what I am trying to resolve. There has to be a vent I can use that I do not have to remove constantly. We do not have to seal up the soffits, at least no one ever told me to. Gosh, maybe I need to find that out. My understanding is that we have to remove the whirlybirds because the wind captures them because they are in constant movement and pulls them off the roof. Then the roof is compromised, weakened and you have a large opening in your roof. Mine are only held on with three screws to a piece of metal. I am pretty sure this is why so many people have removed them. In my ignorant mind, I would think there was a something out there that would have a small fan at the bottom, covered by a curved piece of metal over the top, so that it was NOT rotating around out in the open. At least if there were a cone type piece of metal over the fan, it would not lift in a storm and fly off into the wind. But, who knows I am only an accountant.

nealtw 08-16-2011 07:32 PM

Flat vents don't have a fan or anything, they work by convection with the heat in the attic, I have been told that turbines work better. I would talk to roofers in your are about just adding more flat vents to get the same value as the tubine unless you have to close those too.

gatorfan 08-17-2011 11:25 AM

The purpose of having the fan exposed on the whirlybird is that wind actually spins it to help draw hot air out of the attic (which is replaced with cooler, outside air via the soffits). There appears to be some disagreement about whether the mechanical assist from the whirlybird (or electrically powered fans) is a good thing because although they may keep the attic cooler they may also pull cooled air from the house into the attic, making your a/c work harder. The trade-off is whether the cooler attic pays for the extra a/c.

In any case, non-powered, non-mechanical vents should work just fine, and there should be some that meet the extra-tough wind standards in your area of Florida. Unless you're experienced as a roofer, I would not advise tackling this job yourself. As a pretty experienced DIYer myself, this is a project I would hire out due to the implications of getting it wrong (and if it is, you find out at the worst possible time).


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