radiant barrier
 

i was listening to a home improvement talk show recently and the narrator
kept recommending a 'radiant barrier' in the attic. since i didn't get to
listen to the complete show, i was never quite sure what was meant by a
'radiant barrier'.

i did hear enough to determine that one side has foil, which must face
downward.

is a 'radiant barrier' just a piece of foam insulation with foil on one
side?? or, is it something special that you must purchase?

what is meant by 'radiant barrier'??


i also believe that i heard him say that 'radiant barriers' were really not
effective in cold weather; mostly effective in hot weather.

stevie wrote:
i was listening to a home improvement talk show recently and the
narrator kept recommending a 'radiant barrier' in the attic. since i
didn't get to listen to the complete show, i was never quite sure
what was meant by a 'radiant barrier'.

i did hear enough to determine that one side has foil, which must face
downward.

is a 'radiant barrier' just a piece of foam insulation with foil on
one side?? or, is it something special that you must purchase?

what is meant by 'radiant barrier'??


i also believe that i heard him say that 'radiant barriers' were
really not effective in cold weather; mostly effective in hot weather.

Generally it is any substance that has a shiny metallic service. The
shiny side goes toward the heat.

I would not get all excited about it. In practice they tend not to do
as great a expected for a number of reasons.

First it can only reduce radiant heat. Second if it gets dusty it
quickly loosed efficiency. Third it has to have somewhere to reflect the
heat. In other words the heat has to go somewhere. Generally there are not
many good places to use it in home construction. You really don't want to
reflect a lot of heat up towards your roof, after all heat damages most
roofing materials and during the winter you want to keep the roof cold to
prevent ice dam damage.

--
Joseph Meehan

Dia duit

The information I have says it matters little whether the shiny part
faces up or down, out or in. It also matters little if the surface
gets dirty. Research is still being done, but recent studies are more
favorable than early studies. It is hard to keep up with all the
information on them. Even installed wrong they still work, just not as
well as when installed properly.

Stretch

Probably the best attic radiant barrier is light-colored roofing, to
reduce IR transmission where it matters most.

With adequate insulation & sealing below, and ventilation of attic
space. Ventilation to dissipate summer heating, and prevent snow-melt
and ice-dams in winter.

HTH,
J