[NotFromAroundHere]

Originally Posted by Toymeister

Then you will appreciate that the actual savings from radiant barriers are 3 to 5 percent of cooling costs as measured by users. Or one to two percent of actual electric bills

While 4.32 degrees is great a attic fan that can lower the temp ten to 20 degrees is better.

Guess what? That study found. Wait for it


Three percent savings in COOLING costs.

I think you're saying that either method saves about the same amount? Neither seems like a lot of savings for the investment. 1 - 2% of my electric bill comes to around $20 a year. Not enough to pay for radiant. With a fan, a net of about $10 a year. That will take a while to pay off also. Not worth my trouble I think.

[Gunny2403]

Hip vents are passive and will offer limited ventilation. Prefer Power Vent with humidistat.

[biker1]

You have a humidity problem in your attic? How do you know?

Originally Posted by Gunny2403

Hip vents are passive and will offer limited ventilation. Prefer Power Vent with humidistat.

[biker1]

Yes, we specified spray foam for a new house construction and the builder took care of it. It works well and keeps the attic relatively cool. The attic is completely sealed to the outside. The only downside is that it is pretty expensive so there may be a long payback period. You do save some cost by being able to go with a smaller HVAC system because of reduced heat loading on the house. I did the heat load calculation myself (manual j) and got it correct - I specified a Carrier system with a 2 speed compressor and the system ran nearly continuously at half-speed during the summer with essentially no cycling - this is what you want. The installers must be careful to make sure their mixing guns are working properly otherwise you could wind up with an uninhabitable house. The spray foam is the mixture of two different chemicals. There are two types of spray foam; open and close cell. Each has their pros and cons. I specified closed cell. The attic, in south GA, never got above 85 degrees. The air handler and all duct work was in the attic.

If you get a chance, go visit Green Key Village just outside The Villages. They are building with spray foam insulation and some other proven energy efficient techniques.

Originally Posted by glsatterlee

Yes, Foam is the absolute best. I have begged for two years to have foam sprayed in my new house, during build, but The Villages would not do it. But times are changing, and I’m hearing rumors that it might start happening.

[Heytubes]

Having been in the ventilation business in another life the only ridge vent that is any good is made by Airvent. But keep in mind that the wind has to be blowing to create a vacuum effect. The most effective method is solar power fans placed at the peak of the roof without any ridge caps thus preventing negative air flow, but you must have enough properly installed eave vents, i.e., with the vents facing out for any method to work properly. By the way, there is a 26% Federal Solar Tax credit on the labor and material costs of those fans.

[BostonRich]

Originally Posted by theruizs

I have no idea what the others here know or don’t know either. I do know solar powered fans have done little to no good on our Ivy. We have two but see no difference. I would suggest you get the advice of “real” experts and research actual facts and make your decision based on that. There are a lot of opinions on this forum, but they are just that.

Unfortunately, doing my research on the web leads to the same results. Totally different opinions from the "experts" too.

[Denvercane]

Originally Posted by Toymeister

Let's discuss facts rather than make generalized statements. My facts are based upon a electricity monitor which checks power consumption 10,000 a second. I know how much a fan costs to operate, time of day, hours and minutes a day, month and year

Powered fans come in three flavors, solar, big box store power fans and efficient fans, usually found on line.

I can state unequivocally that solar fans do not operate well into the evening that a thermostat controlled fans do. In other words it quits before the job is done. Readers may love, love their solar fans but that is the cold hard truth. Not enough? Our home inspection guru who posts here is in hundreds of attics here has posted that they make no difference in perceived temp.

That leaves powered fans. But wait exactly how long do fans run in a year? 213 hours.

A big how store fan uses 380 watts or 80.94 kwh a year. At SECO rates that is 9.46 a year.

An energy efficient fan consumes 22 to 120 watts (multiple speeds) or up to 2.99 a year. Quiet cool fans on amazon.

So, cost of operation is simply NOT a factor. You have been given bad advice based upon folklore. I would retain the power vent.

If your house is properly insulated, the venting that is there is sufficient. People try to sale items you don't need. Sorta like those houses with lighting rods. Cooling the attic by 10 deg will make no difference to your electric bill.

[Denvercane]

Originally Posted by Annie66

My oh my ….. we have some folks with their knickers on fire.

I am taking care of a friend's home. I knew he wanted to install a radiant barrier while he was gone, so I placed a remote temperature sensor in his attic. Before the barrier was installed, it read, on average, about 129 deg F during the afternoon. After the radiant barrier was installed, the attic's average temp was 113 deg F during the afternoon. The heat load on the ceiling is significantly reduced.

Who cares about the 10 degrees in the attic. Measure the ceiling inside the house and you won't see any difference. Measure a wall at the 6 foot level where your body spends most of your time. There will be no change. These vents are just a shell game by the sellers

[Denvercane]

It's not 3% of your electric bill. The cooling of the house is only part of the bill. $100 electric bill, $30 of it for AC, so 3% of $30 is less than a dollar a month. Do get suckered in by a snake oil salesman

[islandtiempo]

Originally Posted by RAAndre

Yes, I am getting a new roof. It's original from 2004.

My insurance company has suggested that I replace my large power vent with two hip roof side ridge vents. He said it would be more aesthetic, lower my electric bill and actually function better. I have found articles on the web that seem to support this. Has anyone done this?

I also researched this. Those power vents are not nearly as effective as additional roof venting. Do you mind sharing who is your insurance company. First I've heard of an insurance company being that proactive with good info.

[ProfessorDave]

WOW. Interesting to hear and see all of this advice.
The problem you may have - is that many "hip" roofs don't allow for enough ridge vent to be installed and be to code - or effective.

In my career - one of my responsibilities was for the largest ridge vent manufacturer (and shingle) in North America.
Here is a simple fact: on many of the hip roofs I see in The Villages - a ridge vent does not provide enough "exhaust."
When you don't have enough "exhaust" you have the following potential consequences:
1) Health Risk... because the recipe for mold is warm air, dark environment, organic material and moisture.
2) Void Manufacturer Warranty... every shingle manufacturer requires ventilation to code. Not enough exhaust - not to code!
3) Higher Energy Bills... % moisture in the insulation drops its effectiveness by 1/3
4) Shorten Shingle Life... too much heat to the roof deck fries out the shingles.

Me personally - keep the power vents!

[taruffi57]

I've been in roofing 41 yrs in Cen. Fla. ALL passive vents only depend upon heat rising. The big round vents, ridge venting or 4 ft. off-ridge vents probably allow approx. the same cubic footage of hot air to escape. It is my opinion that solar powered vents probably move more air, but since the solar panel is small, it can't power much of a fan. Hard wired round electric "power ventilators" move much more air, and in 16 yrs. of doing repairs (at least 2,500 jobs) and many power ventilators in The Villages, I have never seen nor heard of any fire from one. That is another myth - like fungus danger. Incidentally, a 3-tab shingle is warranteed 25 yrs. and the architectural 30 yrs. You people are replacing perfectly good roofs - because of your home owner's insur. company telling you that you have too, OR some estimator snowing you. (they work on commission). Lottsa scams going on too.

[taruffi57]

Originally Posted by Chatbrat

Any thing you can do to remove any rotating powered equipment the better, less fire hazard, lower electric bills

Don't be a part of the alarmist/fear/panic crowd. I've been in roofing in Cen. Fla. over 41 yrs. Worked on 5,000 roofs, owned my own company 24 yrs., done 2,500 repairs in TV. NEVER have I seen nor heard of any fire from a powered ventilator. There is no electric-to-combustible-material contact.

[BostonRich]

Originally Posted by Dharrisoncmo@gmail.com

WOW. Interesting to hear and see all of this advice.
The problem you may have - is that many "hip" roofs don't allow for enough ridge vent to be installed and be to code - or effective.

In my career - one of my responsibilities was for the largest ridge vent manufacturer (and shingle) in North America.
Here is a simple fact: on many of the hip roofs I see in The Villages - a ridge vent does not provide enough "exhaust."
When you don't have enough "exhaust" you have the following potential consequences:
1) Health Risk... because the recipe for mold is warm air, dark environment, organic material and moisture.
2) Void Manufacturer Warranty... every shingle manufacturer requires ventilation to code. Not enough exhaust - not to code!
3) Higher Energy Bills... % moisture in the insulation drops its effectiveness by 1/3
4) Shorten Shingle Life... too much heat to the roof deck fries out the shingles.

Me personally - keep the power vents!

Ah true BUT these relatively new "Hip Roof Ridge Vents" go down the sides of the roof.

[Mustagotlost]

Ok so this is information over load. My issue is the garage gets very warm. Would it be best to put a screen garage door and leave my ridge vents alone?