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Insulating plenums in attic

Pebble's picture

Hi all. My mother has had me going up into her attic to seal the leaky ducts and parts of the plenum/air handler that join up to the furnace and coil units. Anyhow the return box and the other box that has the ducts coming out of it are made of sheet metal. It gets really hot up there in the summer and all that thin sheet metal doesn't seem like it helps when cooling the air, yanno? So I was wondering if its ok to take some polyiso boards, cut them to size the best I can and simply cover up some of that sheet metal. I am no AC expert but this seems smart to me. I am sure it doesn't help to have cool air warmed up by the sheet metal in that hot attic. The ducts are insulated just in case anyone was wondering.

Handyman, painter, wood floor refinisher, property maintenance in Tulsa, OK

Handyman, floor refinisher, painter in Tulsa, OK

(post #111980, reply #1 of 20)

bump



sobriety is the root cause of dementia.

 

(post #111980, reply #2 of 20)

Thanks for the bump razzman! I appreciate it :)

I am gonna post this in General Discussion where it might get noticed lol

Handyman, painter, wood floor refinisher, property maintenance in Tulsa, OK

Handyman, floor refinisher, painter in Tulsa, OK

(post #111980, reply #3 of 20)

Improve attic ventilation - will help prolong roof life and make AC more efficient. Soffit vents and/or powered ridge vents even better. There are solar panel powered vents, easy to install and the little PV panels they come with are small and discreet (nice to vent roof during power outages!). Part of the heat you experience in attic is waste heat extracted by the AC itself from return air supply - must be vented outside. 

(post #111980, reply #4 of 20)

The attic is vented on both ends by gable vents and has two vents also in the roof itself. This is a small house, about 1100 sq. ft. But powered vents are a great idea.

What I am trying to do is see if it is ok if I attach foam board to the sheet metal boxes that the return and the ducts attach to. Like a thermal break you know?

Handyman, painter, wood floor refinisher, property maintenance in Tulsa, OK

Handyman, floor refinisher, painter in Tulsa, OK

(post #111980, reply #5 of 20)

Check the manufacturer website or an HVAC forum on the foam panels; I'm guessing they would neither help nor hurt, 'cause usually AC units and even blowers are located outdoors, on roofs or side yards, fully exposed to sun and weather. Are the ridge vents passive "squirrel fan" or "Whiry Dome" style? They are a little antiquated and dont really pull out enough air. You could even just run some window fans in the gable vents off of extension cords for now - bound to help out.

(post #111980, reply #6 of 20)

They are just the whirly gig thimgies lol

The unit in the attic is the furnace/coil/air handler part. The part of the AC that is outside is the part that has that fan in it and blows the hot air out the top you know? There are refrigerant lines going from that to the attic where it goes into the furnace/blower/air handler unit w/the drain pans underneath to catch any overflow. Basically its an octopus nest of insulated ducts and one big insulated return duct. I am a bit perplexed that if the ducts are insulated then why aren't the sheet metal boxes that the return/ducts attach to aren't insulated as well? Like the ducts are?

Handyman, painter, wood floor refinisher, property maintenance in Tulsa, OK

Handyman, floor refinisher, painter in Tulsa, OK

(post #111980, reply #20 of 20)

 I am a bit perplexed that if the ducts are insulated then why aren't the sheet metal boxes that the return/ducts attach to aren't insulated as well? Like the ducts are?


They may be insulated on the inside as was sometimes done for sound proofing.


 


 

Never say anything bad about a person untill you have walked a mile in his shoes, by then you will be a mile away from him and you will have his shoes.


 

(post #111980, reply #7 of 20)

you know JAGWAH????


Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!!   What a Ride!


Forget the primal scream,  just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #111980, reply #8 of 20)

No I dont. Is he the guy I should ask about this?

Edit : Ohhh I see. He lives in the same town as I do! lol I don't know him. Cool! A local Breaktimer :)

Handyman, painter, wood floor refinisher, property maintenance in Tulsa, OK


Edited 4/22/2005 1:43 am ET by Pebble

Handyman, floor refinisher, painter in Tulsa, OK

(post #111980, reply #9 of 20)

there is insulation board by Armaflex and RBX and foil backed FG duct wrap made just for what you want to do...


go over to Johnstone Supply over at 9530 E 55th Place, Tele #664-1990....


product numbers are


(board) B92-593, B92-595, B94-756, B94-757.. Yur choice...


or


(blankets) couldn't find the #... the boards are the better bet...


don't let razzman slide.. he could have told you all of this....



Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!!   What a Ride!


Forget the primal scream,  just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #111980, reply #10 of 20)

Thanks IMERC I have a bunch of foilfaced isofoam board left over from an insulating project I did on my place so I will try and use it and I have some foil tape somewhere but never have heard of foil backed fiberglass things.

Ah well its ok if razzman felt like keeping quiet I just wanted to make sure I wasn't doing something dangerous somehow. I am sure he woulda said something if it was.

Brought the isofoam to my mom's today and will put it in in the morning before the sun makes it hot up there.

Handyman, painter, wood floor refinisher, property maintenance in Tulsa, OK

Handyman, floor refinisher, painter in Tulsa, OK

(post #111980, reply #11 of 20)

foam will trap condensation against the tin... corrosion is next...


we're glad you see razzman that way...



Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!!   What a Ride!


Forget the primal scream,  just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #111980, reply #12 of 20)

aha I knew there was something I was missing! I will go to Johnson supply and check that stuff out :)

Handyman, painter, wood floor refinisher, property maintenance in Tulsa, OK

Handyman, floor refinisher, painter in Tulsa, OK

(post #111980, reply #13 of 20)

I can't remember exactly where the used book store is but rez does and they have a pretty good selection of books on the trades..


the folks there know their way around and have good contacts... tell'em I said HI!...


BTW.. that is why I said FG board or wrap and left foam out of the conversation...



Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!!   What a Ride!


Forget the primal scream,  just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #111980, reply #15 of 20)

That would be Gardners bookstore. I go there about two or three times a year.

This was exactly the kind of thing I needed to know. FG board and wrap it is.

So JAGWAH is your brother? I'll be darned. I don't know why but I'll just be darned :)

Sorry to make you nervous about my painting handle. It's just that I have a reputaton for being the best painter that my clients have ever used. I don't like it too much but I am good at it. I used to seal and stripe asphalt parking lots for seven years and when I quit it was a kind of natural extension to go from working outside in 100 degree heat painting parking lots to painting houses in air conditioned comfort.

Forgive me if I don't introduce myself to JAGWAH right away. I am kind of shy and just see how things go before doing anything. But yeah maybe one day it would be cool to have a burger or something :)

Handyman, painter, wood floor refinisher, property maintenance in Tulsa, OK

Handyman, floor refinisher, painter in Tulsa, OK

(post #111980, reply #16 of 20)

swimming in a septic is preferable to painting... v


yup.. Gardner's it is... rez use to work there... (on it) ask him about the gutters and roof sometime.. another one of those projects from hell...


A shy BT'er... this is some thing new... and yur plight is accepted...


if yur buying... bring a huge bank roll....



Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!!   What a Ride!


Forget the primal scream,  just ROAR!!!



Edited 4/22/2005 3:45 am ET by IMERC

"Some days it's just not worth chewing through the restraints"

(post #111980, reply #17 of 20)

we're talkin' about ya...


Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!!   What a Ride!


Forget the primal scream,  just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #111980, reply #18 of 20)

swimming in a septic is preferable to painting... v


EEEWWW!! You got that right tho


Hey IMERC a question? What part of Just A Guy With A Hammer says heat n air? I know a few bodies to call.


Now if ya got something to nail I'm yer man...


Hidy ho Pebble


 

 

 

(post #111980, reply #19 of 20)

well bro.. it ain't got anything to do with heat n'air...


almost got somebody to buy ya coffee and a sammich...



Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!!   What a Ride!


Forget the primal scream,  just ROAR!!!

"Some days it's just not worth chewing through the restraints"

(post #111980, reply #14 of 20)

get rid of the painter handle... yur making me nervous.. ROAR!!!


get a hold of JAGWAH (my brother)... he's a very talented dude and dam fine guy...



Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming


WOW!!!   What a Ride!


Forget the primal scream,  just ROAR!!!

"Some days it's just not worth chewing through the restraints"