Hi, I'm Ed Fritz, the owner of AtticFoil.com and I'm calling this video the MEGA installation
video.
In the next 15 minutes I'm going to give you all the information you need to know about
stapling up AtticFoil brand radiant barrier in your attic.
I'm going to cover the basics, answer the most common questions and give you some tips
and tricks to make your job go fast and easy.
This is about a 15 minute video and it's in three parts and I GUARANTEE you'll learn more
in the next 15 minutes than if you spend hours searching elsewhere.
First I want to talk about the BIG picture.
People tend to over think things when it comes to installing a radiant barrier.
Here are the only two things you really need to focus on: first, cover as much area as
possible.
The more coverage, the better the results, but don't go crazy and spend hours trying
to get some small, hard to reach, area down in the corner of your attic.
Installing radiant barrier has a cumulative effect.
We want to get the big, open areas first and worry about the small, hard-to-reach areas
later.
Secondly, air should flow through the attic as though the foil really isn't even there.
Ideally air should come through the bottom of the attic (in through the soffit vents)
and either run between the foil and the roof deck or be drawn to inside the attic.
Hot air is all going to end up at the top of the attic one way or the other.
Hot air kinda flows like water toward a drain.
The key is you want to give it an unobstructed path to come in and go through the attic,
and then get out.
Also, I want to talk about the true goal of installing a radiant barrier.
Contrary to what is often promoted, the goal is not to cool down the air temperature inside
the attic.
Yes, that does tend to happen, but our true goal is to cool down the temperature of the
insulation.
Here's what happens: the sun heats up the roof (it can typically easily get to 180 degrees
or more on the top shingles), the bottom of the roof deck can easily be 150 degrees!
Once the roof gets hot, it is going to radiate heat across the attic and heat up the insulation.
This is the definition of radiant heat: heat transfer by non-contact.
The roof heats up the insulation without ever even touching it.
It is not hot air in the attic that heats it up, it's the infrared radiation (or heat)
being emitted by the roof that heats up the attic insulation.
Radiant heat is the invisible part of the light spectrum - it travels at the speed of
light until it is either absorbed or reflected.
In a typical attic, the heat comes off the roof and is absorbed by the attic insulation.
Typically the top surface of the insulation can reach 130 degrees or more.
This means the top of the insulation is 130 degrees and say the inside of the space where
you are living, you want it to be 75 degrees.
That's a 55 degree difference, which is called the Delta T, and results in a lot of heat
coming in to the home.
Many people will say, "Hey!
Just add more attic ventilation," which will help, but not so much.
You can have great air flow through the attic but it will only drop the top surface temperature
of the insulation a few degrees.
This is kinda like blowing a fan on a hot, sunny driveway and expecting it not to get
hot.
it just doesn't work that way!
Using the driveway as an example again, if the driveway is in the shade, then the concrete
really can't get any hotter than the actual air temperature outside.
The same thing happens right here between the roof and the insulation.
We want to put the insulation in the "shade" not from the light, but the shade from the
HEAT coming off the roof.
Since radiant heat can only be either absorbed or reflected, we can easily reflect the heat
coming off the roof back toward the roof and keep the top surface temperature of the insulation
cooler.
After installing a radiant barrier, the top surface temperature should only be a few degrees
warmer than the outside air temperature.
This is how radiant barrier works, by reducing the Delta T. If we can reduce the Delta T,
that means less heat is coming from the roof, through the insulation and into the home.
And less heat coming in means you have to spend less money to get the heat out and the
home will be more comfortable.