What is behind A/C register vents.......?? (grills, bathroom, cleaning)

[VintageGirl]

So I have an older home that we bought.........I looked up the vents and the are dirty, we removed a register vent and when you look up there is the metal air duct boot I guess but it seems that there like a lining? insulation possibly?? is black dirty along with all the dust in the vent........... is this insulation that is in the air duct boot or what? I am not familiar with this stuff...........I assume it needs new ones.........??

[MrRational]

Originally Posted by VintageGirl

So I have an older home
the vents are dirty
there is the metal air duct boot

Clean examples of all of these duct work components can be seen and handled in person at most home centers.
Few are likely to be exactly what you have in an older home but they'll be close.

it seems that there like a lining?
insulation possibly??
I am not familiar with this stuff...........

duct insulation is unlikely in an older home.
especially anywhere you might see it.

Take a few photo's and bring them with you when you go the store.
Ask the old guy what it is. (or post a pic here?)

I assume it needs new ones.........??

never assume.

I've never done it myself but there are contractor types who do duct cleaning. It might be appropriate for you.
Replacing a few registers and grills and even some boots is well within the realm of reasonable too.

But I'd start with really knowing whats in there first.

[chet everett]

First, when you say "older" do you mean like built when JFK was in office or Abe Lincoln? If this is from the Abe era when was the forced air system retrofitted?

I can't think of too many types of insulation that is supposed to be "blacK" -- even rock wool is mostly grey-ish. So I would lean toward the stuff just being FILTH, but maybe post a picture if you can aim at it...

[chet everett]

First, when you say "older" do you mean like built when JFK was in office or Abe Lincoln? If this is from the Abe era when was the forced air system retrofitted?

I can't think of too many types of insulation that is supposed to be "blacK" -- even rock wool is mostly grey-ish. So I would lean toward the stuff just being FILTH, but maybe post a picture if you can aim at it...

[VintageGirl]

Its a 1970's home, there are so many details I must have missed during inspection and knowing what questions to ask, since neither inspector pointed anything about it being a concern I did not question. I thought I did all my homework before buying but I guess I lack experience.........I wish I had made the previous owners get them cleaned. I hope its not mold though :-/

[MrRational]

Originally Posted by VintageGirl

Its a 1970's home...

That's cute. An fyi:
In the context of homes a statement like "an older home" implies pre war (WW2) at least;
most would say it predates electricity and even indoor plumbing. Just so you know.

...there are so many details I must have missed... I hope its not mold though :-/

Unless you're in New Orleans or Oregon... it's not likely to be mold.
It's probably just filth and dirt on top of the galvanized sheet metal.
If you're inclined to create a job for yourself you might clean them yourself
with brushes made for the purpose.

(Chet: I was thinking it might be old black iron made on site fittings)

[VintageGirl]

:-) I am silly with the "old house" comment, but I guess what I mean to say is that it was not new construction

Well the air vent boot definately has some lining inside and it seems like insulation or a sponge ..........the one in the bathroom is actually a bit damp..........not sure if its condensation or what not........... I guess I willl have a professional go out and look at it. I did not realize how many things you have to keep up with with purchasing a 30+ year home............. :-(

[MrRational]

Originally Posted by VintageGirl

Well the air vent boot definately has some lining inside and it seems like insulation or a sponge ..........the one in the bathroom is actually a bit damp.

This is really weird.
Insulation when it does exist is (should be) on the OUTSIDE of the sheet metal duct.

OK; other ideas:
1) The wall itself is part of a return air chase.
Rather than bending up metal to make a duct they'll use the area between the studs itself as the duct... it's also possible this way of doing things was done on the supply side too. The tempered air could cause condensation which in turn etc...

2) An insulation board was made up into ductwork in that era and parts of that might be where you're looking.

I guess I will have a professional go out and look at it.

Good idea. Please let us know what you find out.

[nowitsshowtime]

As stated, insulation on a vent is usually on the outside. The inside should be metal or some sort of flex pipe I suppose. Perhaps it is just a lot of dust built up. If its forced air, check out the filter is on it. Maybe scrape away at a small section a bit, see if you get to the metal below.

[VintageGirl]

Thanks for the advice everyone, I will let you'll know what we discover, its almost scary to see all that build up in there :-( meanwhile I am using an air purifier, I hate this stuff !!