Help me understand this air conditioning system (home builders, inspector)

[phoenix_new]

I have a separate office in my home with a separate Air conditioning system.. this is the first time i am replacing the filter and I am little confused by looking at how this system works... can you check attached pic and help me out...thanks..in this pic.. i have the AC housing open and I removed the old filter and put a new one (green)...if i close this housing then what is they greying cloth/sponge like stuff hanging... this will be on top of the filter, correct ? so why do i need the filter here..??

[HX_Guy]

Um that grey thing shouldn't be there from what I know, usually you can see right into the duct if the filter is off.

[phoenix_new]

Originally Posted by HX_Guy

Um that grey thing shouldn't be there from what I know, usually you can see right into the duct if the filter is off.

Thats what I am confused, If I remove the grey thing... then I don't see a duct ..i see a big machine.. so from where the air is going into the system?

[wit-nit]

OP...Some questions: did you have the unit installed, do you know who installed it, is there an instruction manual for it, who is responsible for the unit if it goes on the fritz.
What model/manufacturer is the unit. How long have you had it.
There should be no obstructions behind the filter like you describe.
These are all questions to possibly help you.

[phoenix_new]

Originally Posted by wit-nit

OP...Some questions: did you have the unit installed, do you know who installed it, is there an instruction manual for it, who is responsible for the unit if it goes on the fritz.
What model/manufacturer is the unit. How long have you had it.
There should be no obstructions behind the filter like you describe.
These are all questions to possibly help you.

This was installed by original owner, my house is 10 year old... so I dont have any manual etc....i can check the model/manufatcurer etc

[Zippyman]

the gray foam stuff looks like some sort of filter - but it would be worthless for filtering if it is as "floppy" as it looks..

I'm wondering if that was some sort of DIY "pre-filter" that somehow ended up on top of the normal filter?

In any case, you don't need that gray foam stuff.. it isn't doing anything but restricting airflow -

it's possible that it may have originally been a sound deadener, designed to reduce the noise when the airflow starts & the ducts bend?

On a 10 year old house, they weren't allowed to run wiring in the return ductwork - the install may be a hack job..

[phoenix_new]

Originally Posted by Zippyman

the gray foam stuff looks like some sort of filter - but it would be worthless for filtering if it is as "floppy" as it looks..

I'm wondering if that was some sort of DIY "pre-filter" that somehow ended up on top of the normal filter?

In any case, you don't need that gray foam stuff.. it isn't doing anything but restricting airflow -

it's possible that it may have originally been a sound deadener, designed to reduce the noise when the airflow starts & the ducts bend?

On a 10 year old house, they weren't allowed to run wiring in the return ductwork - the install may be a hack job..

The install was done by the builder... and its a very reputable one... I will remove this foam, take a picture and post it here to understand the air flow...

[Zippyman]

Originally Posted by phoenix_new

The install was done by the builder... and its a very reputable one... I will remove this foam, take a picture and post it here to understand the air flow...

lol.. no such thing as a "reputable" builder in the HVAC trades..

they use whoever is cheapest..

but definitely post a pic without that foam.. - it's weird that it has oversprayed paint on it - looks like it was present when the house was built, possibly a filter to keep drywall dust out of the hvac system before the original owner moved in?

it's an interesting setup you have there.. never seen a filter-grill quite like that one with a blank panel on one side..

and those wires (cat 5? phone wiring?) definitely don't belong in your ducts - it's not a big deal if the owner does something like that, but it's an instant fail with a building inspector.. (fireproofing - any holes in the ducts to allow wiring to pass through can allow fire into the ducts & allow it to spread)..

fwiw, here's an electrical code training video that mentions this kind of wiring in ductwork -

http://youtu.be/hD-RdBAFbzg?t=2m15s

[Pink Jazz]

Originally Posted by Zippyman

lol.. no such thing as a "reputable" builder in the HVAC trades..

they use whoever is cheapest..

And with most tract home builders, there is basically a duopoly for HVAC companies here: either Chas Roberts or Sonoran Air. Rarely do you see tract home builders around here use any other company but those two. Not sure if the OP's home is a tract home or not, but I wouldn't be surprised if it is, and if it is, the system was likely installed by either one of those two companies.

[johnp292]

Originally Posted by Zippyman

lol.. no such thing as a "reputable" builder in the HVAC trades..

they use whoever is cheapest..

but definitely post a pic without that foam.. - it's weird that it has oversprayed paint on it - looks like it was present when the house was built, possibly a filter to keep drywall dust out of the hvac system before the original owner moved in?

it's an interesting setup you have there.. never seen a filter-grill quite like that one with a blank panel on one side..

and those wires (cat 5? phone wiring?) definitely don't belong in your ducts - it's not a big deal if the owner does something like that, but it's an instant fail with a building inspector.. (fireproofing - any holes in the ducts to allow wiring to pass through can allow fire into the ducts & allow it to spread)..

fwiw, here's an electrical code training video that mentions this kind of wiring in ductwork -

NEC 2008 Wiring in Plenums Spaces 300.22 - YouTube

Looks more like Romex to me!