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Here are the specs pdf on the Lowes gable mount link:
http://www.airvent.com/pdf/literature/Po...ochure.pdf
You can also just install LARGER gable end vents (if you drive around Hilo, you will see many older homes w/gable ends that are all decorative grill work & open venting....and some with clearstory or cupola vents....
Also look at your ridgeline venting.... some people seal or foam up these, better to screen them (still does reduce your free vent space.... but not as much as sealing them!
The turbines do work, but can be knocked a bit by wind... and you still need to put a hole in your roof.... and some are a bit rusty (there are some in downtown Hilo, off of Keawe)
No matter which way you go, you do need to look at your eaves & radiant barriers.... they give you the greatest "bang for the buck".
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hotinhawaii, so what do you do, staple the radiant barrier to the rafters/joists (not sure what they're called) just under the roof? Since one room has radiant barrier on the top of the ceiling's drywall, should I add another barrier, then, to the underside of the roof? Or perhaps remove what's on top of the drywall? and in the room w/o the present barrier, should I install both under the roof AND on top of the ceiling's drywall? i.e., ergo, would two layers help or hinder?
And good idea, Carey, on making the vent areas BIGGER. Right now, both look like, say 18"x24". I'm liking the idea of avoiding the whole hole-in-the-roof scenario.
Many mahalos!!
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Rafter is the angled top board, joist is the horizontal bottom board on a truss
Yes, you can staple the radiant barrier onto WOOD rafters (our rafters are aluminum, but our perlins are wood, so that is what we used to staple onto, and squished the Reflectix up over the rafters, as our metal rafters act as a heat conductor... but most do not have these issues...)
ETA: 2 layers do not do much (we did a small area experiment....) but if you can/want to afford to get new barrier, and leave the old where it is, it might be easier (depending on how long it has been sitting up in the attic, it may have a grunge layer that makes it easier just letting it be...but it can also be cleaned off with a hose... again, we have been working on this roof heat reduction for a while & have done a bit of experimentation)
Oh - and choose stainless or Monel staples, as regular staples are gone in very little time here, and you will be back up in the attic, re-stapling saggy radiant barriers
ETAII: Oh, the pink stuff? it makes the best rat & centipede bedding { yes... this is from experience on this house.... and one of the reasons we have had the ...er... oppurtunity .. to learn so much about building here....)
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Adding another layer will help only if the first layer is dirty or corroded. There is no reason to remove the first layer, it won't hurt. Installing it closer to the roofing is best. You can staple it to the underside of the rafters or between the rafters, whatever is easier. As long as there is at least 3/4 inch between the metal roofing and radiant barrier, you are fine. You don't want dirt to easily settle atop the barrier.
I'm with Carey on using rust-resistant staples! And I have also seen the pink stuff make a fantastic rat nest!
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The "pink stuff" has worked for me for almost 20 years now. When our house was first built...it had no attic insulation and every room was "really hot" when days were sunny here near the HPP coast. Within the first year we installed 3 inch thick insulation (I forget the R value)...and my god what a difference it made. No attic fan...no radiant barrier....just good old fiberglass insulation. I just recently went into the attic and took out all the old fiberglass and replaced it with new. I didn't find any evidence of rat or centipede bedding.
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foil faced fiberglas insulation has radiant barrier properties.... insulation without the barrier does help.... but the radiant barrier is REALLY helpful here, and for the cost & ease of installation, the barrier usually is a good start....
the bedding issues would only be if the varmits were allowed in...something we are working hard to make sure never, ever happens again here...(it is a process of elimination... access, incentives & food...& we are trying to get all three way down, from being an open house to all!)
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Fiberglass insulation works in the ceiling by keeping the heat that builds up in the attic in the attic and not allowing it to convect and transfer heat to the ceiling below. Imagine if you could keep the air in the attic from getting so hot in the first place.
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quote:
Originally posted by hotinhawaii
Imagine if you could keep the air in the attic from getting so hot in the first place.
That's why I'm thinking the solar attic fans might be a good idea. Am juggling the possibilities.
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I think you are missing my point. Why would you need a solar attic fan if the air in the attic isn't so hot?
Regardless of the temperature of the attic air, radiant heat will pass through the roof, attic, fiberglass insulation and ceiling without a radiant barrier.
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off the wall idea, but ....
Would running a dedicated water line "radiator" type loop through the attic and directly into your hot water heater achieve anything?
(i.e cooling attic and warming water?)
I think of this stuff and then Robert tells me why it wouldnt work so you guys just jump right in.
