Furnace duct repair question

[chassis]

Hopefully some HVAC savvy folks can chip in on this one.

Background: house built in 1950, gas forced air furnace. Our remodelled master bath doesn't get heat or a/c through the register, so I started poking around to find out why. I found the supply duct in the basement, but it is disconnected from the main supply manifold. My guess is that the previous owners disconnected it when the basement was finished.

Question is how do I go about reconnecting the duct? The supply manifold is close to the duct. I need to pierce the manifold and install a 90 degree elbow up to the master bath duct.

The bath duct is 3x10 rectangular. The supply manifold is pretty big, I guess about 18x24 or thereabouts. Should I be looking at a round-to-rectangle fitting to make the connection? What tool should I used to cut the hole in the supply manifold? Thanks for any advice.

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[cx]

First, what material is the "manifold"/plenum?

Yes, you find a rectangle-to-round transition. Yours is gonna be so common you can prolly find it at Homer's. Gonna be 3x10 x 6(dia) most likely.

You don't need any duct between that and the 90 into the plenum?

To go into the plenum (ours are usually ductboard, but sometimes sheet metal), there is a fitting with a collar and a whole buncha tabs on the part that sticks through the hole you poked in the wall of the plenum/manifold thingee. You stick it in, reach in through the hole and fold the tabs back against the wall onna inside. Then you tape everything up real good and maybe paint on some duct pookey for good measure.

Then you go sit by the new duct and say, aaaaaahhh. :D

My opinion; worth price charged.

[chassis]

Thanks cx. Duct pookey sounds good. I'll buy some just so I can use it. ;)

Plenum, that's the word I was looking for. The plenum is sheet metal. Not like that furrin Lone Star country where they make stuff with adobe or gutta percha. :D I'll stop at Homer's during lunch tomorrow so's I can git this thing fixed so the Misses gets happier than her normal happy self.

[cx]

I don't know if Homer's got the good kinda duct pookey. Never looked. Steal mine from my HVAC guy. White in color. Thick, paintable kinda stuff. Do not get some on anything you don't want some on, or you ain't gonna have you no happy wife soon enough. :shades:

On metal ductwork, NP-1 works really well, too. Homer don't have that, neither. Same warning as above. :)

[Westie]

Hopefully some HVAC savvy folks can chip in on this one.

What tool should I used to cut the hole in the supply manifold?

When I installed a humidifier I used a jigsaw to cut the hole in my duct. Makes quite a bit of noise but if you keep the speed of the jigsaw quite high and use a fine tooth blade it works well.

[chassis]

Thanks Westie. I've got my evening project for the night! ;) It will be nice to have a relatively toasty bathroom, compared to the ice box we have now.

[flatfloor]

Alternately you could rip out the whole bathroom floor install radiant heat by Warmly re-tile with new ceramic and as long as you're at it put in a new Kerdi shower maybe a new sink and vanity. Course the exuberantly happy missus will probably want some matching wallpaper and blinds. Only cost a few dollars more. :D

[chassis]

flatfloor,

Good one! ;) I have a million "lessons learned" from doing this bath remodel project. One of them is a heated floor. Oh well, there's always next time! ;)

I made the trip to Homer's today and have the bits and pieces I need. Hope I don't lose too much blood working with the sheet metal. Sliced my hand just playing with the pieces in Homers. duh

[flatfloor]

Just trying to help. ;)

[slb]

Not trying to be an alarmist, but be careful with old duct insulation. If it is a foil faced paper insulation, there's a good chance that it contains asbestos. You don't want to get asbestos particles into your duct work because they'll end up being blow into your house.

[Dave Taylor]

Course the exuberantly happy missus will probably want some matching wallpaper and blinds. :D
an a matching new Caddy inna driveway, an a matching "Flat" screen T&V, an a day maid with matching hair (that might not be too bad Will :shake: ) an a bank account wif matching check book, an a matching Mastercard with matching Gucci handbag and watch, an a.................. :eek:

[chassis]

e3, the duct is a 3x10 "stub" of galvanized, same with the main plenum. Insulation? What insulation? My experience with homes built prior to 1955 is very minimal insulation, and definately none on the ducts.

Dave, yep I hear ya. Got the TV, but still need to work on the Caddy and day maid. Might forego the checking account if the day maid met the right "specifications". Happiness has its own value. :rofl: :tup2:

[chassis]

Got it fixed tonight, works great! Thanks for the help guys! :tup1: