replacing direct vent

[nile]

i am currently replacing my builders model direct vent with a valor horizon
the installer came to day to remove the old on and rough in for the new
i had a look in the old space and up in the dog house and it is a disaster
very little dry wall , very cold poor vapour barrier etc
what would be the best way to prepare the dog house for the new unit insulation wise
the dog house is 18 inches deep and 9 feet tall and 5 feet wide
anyone with suggestions or direction would be greatly appreciated

thanks
nile

 

[DAKSY]

Hey, Nile...
If you really wanna do this in a manner that will keep MOST of the cold air penetration out, this
is the way we do it...
Pull of ALL the sheet rock out & have your contractor frame the opening for the new direct vent
maintaining the proper clearances...
Install the highest R-value Kraft-faced insulation you can get to fit your framing in between the studs & staple it securely,
run the sections of insulation at least 4 feet up, UNLESS your unit & venting go higher than 4 feet,
then you'll hafta adjust everything up...
You can go all the way up if you like, it just costs more...
Install new (or the old) sheet rock, four feet up from the floor...
We install the rear one first, going fully across the rear of the chase,
covering the vent hole framing, & then put the side wall sections in.
Next, build a 2x4 'band' around the chase above where the firebox & venting will be...
For our standard 36" wide gas fireplaces, we generally install the band at 42" from the floor...
You may have to go higher, depending upon how your unit vents...
Apply caulk (silicone or whatever) to ALL seams...where the sheet rock meets the floor...
Where the sheet rock meets in the corners & to the seams where the sheet rock meets the 2x4 band
Cut a piece of sheet rock for a 'deck' to fit on top of the 2x4 band...
Cut some insulation to fit on top of the deck & attach it with silicone between the Kraft-face & the sheet rock...
You should be able to slide the deck/insulation assembly up above the band & drop it onto the band with the
insulation on the top side...
The silicone should hold the insulation in place...
Apply caulk to the seam where the deck meets the band...
With a sawzall, cut out the sheet rock covering the vent hole & install your wall firestop with roofing nails...
Use Aluminum tape to seal the firestop/sheetrock seams...
While this won't make the chase (or Doghouse) any warmer, because it sits OUTSIDE your house,
it will cut down on COLD air penetration from the outside...
PM me if you don't understand any of this...
I've probably installed hundreds of dv Fireplaces using this method & it's a little difficult to write the instructions
in a manner that makes sense to others...