Duct work material options

[shark_1968]

Greetings to everyone,

Background:

I have been doing some research on environmentally friendly ductwork installations and have seen many arguments against using uncoated duct board. The disadvantages range from a breeding ground for dust mites and mold to inhalation of micro fiber particles and formaldehyde.

As I have a newborn in my household and my duct board boxes and lined flex hose are all black on the inside, I am looking to replace the entire ductwork system. My ductwork is in the attic and will primarily be used for cooling a small 1300 sq/ft Florida home.

The entire current system is all lined flex hose connected with triangular duct board junction boxes and terminated with duct board register boots.

Questions:

1. What are my options for replacing the junctions, plenum, and register boots with non fibrous duct board material?

1. If it's sheet metal, is there a way to insulate them just on the outside up to R6?

2. My longest current flex hose run is about 11 feet. Is it possible to design a system using only flex hose that is properly sized?

Example:

10 Ft. |===============|Boot 1| || 9Ft. || Plenum =======|Triangle Junction| || || || || 5Ft.|| |============|Boot 2| || 11 Ft. || |Boot 3|

Thank you in advance for any suggestions,

Dmitry

[Moe Jones]

You do realize that will be costly. Have you ever thought of having the duct cleaned?

I am not a big fan of having the duct cleaned but a number of people thinks it was worth it.

[shark_1968]

Moe,

Flexduct is fairly inexpensive, so cleaning it doesn't make sense to me. Especially because the entire sytem is now flexduct. Also, my main objective is to get away from the my filthy fiberglass unlined board that my boots, plenum, and junctions are fabricated from.

I am currently looking into Johns Manville 'superduct' board. It is lined with protective coating on the airflow side. If I can get a few sheets of that, I could make my boots, plenum, and juntions.

Thanks for the response, Dmitry

Moe J> You do realize that will be costly. Have you ever thought of having the duct > cleaned?

[Oscar_Lives]

Oh, now that sounds real nice...

[Noon-Air]

Quit screwing around and do it right.... Tin ductwork with bubblewrap insulation.

[gofish]

Bubblewrap doesnt meet building codes in many areas. Tin and flex in Ca requires R-8, which so far nobody's stocking....code has been in effect 8 mos....

Dmitry, visit Loews or home cheapo and check out the sheet metal T-Wye's in the hvac section. Add volume dampers to the branch legs, then all new flex. Feel free to insulate all sections of duct as thick as possible.

[shark_1968]

Thanks. This will take care of my junctions from the trunk.