Maybe silver, if the furnace filter transmits no sun.
This stuff may melt before it burns.
As I recall, Styrofoam works to 130 F without softening, and so on.
A fail-safe system to keep the furnace filter from melting?
Thanks for the comments Nick,
On 24 Sep 2003 09:09:13 -0400, firstname.lastname@example.org wrote:
I still have wood in my duct (pine) and a little extruded polystyrene,
and a few hopefully non combustible bugs. I was thinking sprinkler
heads in the country aren't a bad idea anyway. Not sure on cost yet,
but seems straight forward enough to install. One inside the system
would cool things down quickly, if it is one that would turn off when
it cooled down. I was also considering some little misting nozzles
somehow controlled by a snap switch to cool things down if they ever
got to 200F or so.
Right ... I had a couple stagnant (fan off) partial days last year
without any melting of the filter material or extruded polystyrene
(near the top of the system) last year, but still seems like a good
idea to keep temps more like 140 than 240 if power is off. The parts
I melted last year were from pushing insulation on the back side into
the plastic sheet backing and causing a dead zone. I think one of my
filter sections had also dropped down a little allowing direct sun on
the black and clear plastic, with the melted pink foam behind that.
The polyiso' solid backing will fix that flaw in design.
I bought another of those 10", 550cfm Grainger fans for the first
floor. (You get 10% off if you're a Farm Bureau member, which my
uncle is) I had one for my second floor (basically same design) last
year, but I'm sure I don't get 550cfm blowing the hot air down 18' of
10" insulated duct.
Good luck at your Denver conference ... sounds interesting.