Replies

1. 
   brownbagg | Nov 08, 2009 06:25pm | #1

   why not just build with 2x6
1. 
   frammer52 | Nov 08, 2009 06:29pm | #2

   I am pretty sure he will have to with the new energy rules.

2. 
   ringtail | Nov 09, 2009 02:47am | #10

   In interior walls as well?

2. 
   davidmeiland | Nov 08, 2009 06:32pm | #3

   3-1/4 x 10 duct fits a 2x4 wall.

1. 
   frammer52 | Nov 08, 2009 06:49pm | #4

   Kind of leaves no room for the insulation>G<

1. 
   davidmeiland | Nov 08, 2009 07:18pm | #5

   Yeah, well, 2x4 walls never were about insulation, were they?

1. 
   brownbagg | Nov 08, 2009 07:45pm | #6

   but why in the wall, ceiling easier

1. 
   davidmeiland | Nov 08, 2009 08:22pm | #7

   In some cases you want to get a supply register in the floor or wall right under a second-floor window. Might mean going up thru the first floor exterior wall. IMO it's easier and better to install a hydronic system but not everyone does.

2. 
   brownbagg | Nov 08, 2009 10:23pm | #9

   its really werid how different construction method are in different parts of the country. I have never seen a floor or wall supply here, all been ceiling, second floors, maybe ten percent of the houses, basements none. In fact houses with crawl spaces are rare. 90% ate slab on grades.

3. 
   Clewless1 | Nov 08, 2009 08:53pm | #8

   Do 2x6 @ 24oc ... it's common knowledge that it is better. Construction labor is cheaper even if there is a little more material (although I've heard the material is about a wash. 2x6 is so common, I fail to see why anyone would do otherwise. Just say no to 2x4 unless you have some other plans for keeping a high R-value (e.g. foam insulation).

   This is even more true if you are putting vents in the wall. Leave room for insulating behind the duct.

   Why put the vents in the wall anyway? If you have e.g. issues w/ furniture covering a vent, it will still be an issue if that vent is in the wall behind the furniture. I think the efforts of placing in the wall is GENERALLY not offset by it's advantage. There is a time and place for everything, though and maybe your situation will tend to warrant the choice. I can't imagine a whole house warranting that, though (but I've no knowledge of what is driving this decision).

1. 
   ringtail | Nov 09, 2009 02:54am | #11

   I have dogs and cats. Have had them get toe/toenail caught in vent in floor-very painful and messy.

1. 
   Clewless1 | Nov 09, 2009 03:40am | #12

   Now there is a point of view I had never heard of. A darned fine one at that. There is always the potential of the point of view that the readers haven't thought of. Easy to do. Guess I'd consider ceiling diffusers then, but every approach has it's +/-.

1. 
   CapnMac | Nov 09, 2009 08:00am | #13

   Might behoove many of us to remember the proposed building is in Charlotte NC, where humidity control may be a bigger issue than how to warm the building.

   Now, running returns in interior 2x4 walls can be done--if not leaving a lot of plate left if run through one or both. 

   I cannot imagine a circumstance where running ductwork in an exterior wall makes any sort of sense at all.

   Now, running ductwork probably better than just using open framing bays (as a certain large national builder did all over northern Texas).  But, either approach will always be at risk as the Design Committee will require some hunk of artwork or decor which will want really long fasteners, which will naturally puncture the plenum, in either construction method.  Not so bad on the lower-pressure return air side, but rather annoying on the supply side of things.

   As said earlier, current RezCheck will likely require more than a 2x4 wall.  Or, if it does, with strapping and additional rigid insulation on one side or the other.Occupational hazard of my occupation not being around (sorry Bubba)

4. 
   rdesigns | Nov 09, 2009 06:27pm | #14

   2 x 6 construction is a good idea for all the reasons mentioned, but the location of the supply registers is a topic of its own.

   Since you are in a cooling-dominant climate (your 99% winter temp is only 23 degrees, but summers are very humid and hot), consider going with high sidewall registers located on an interior wall, especially if the floor itself is not a slab-on-grade or cold from some other type of construction.

   Several studies have shown that the conventional wisdom of locating registers below windows is not really needed if cooling is the primary need of the system, and, in the case of cooling effect, not as good as high sidewall registers.

   Locating them on an interior wall generally means you'll have shorter branch runs, so you end up with better velocity at the register, which, in turn, provides better throw to mix and distribute the air. You get more temperature uniformity throughout the room. Be sure to use registers that throw the air parallel to the ceiling, so that you don't create drafts in the occupied zone (the level from ankles to neck) of the room.

   With high sidewall registers, you also have no issues with furniture or drapes messing with the airflow.