Rigid plastic conduit: unidirectional

Good judgment comes out of experience. Experience comes out of bad judgment.

It seems pretty obvious in hindsight, but somehow didn't come to my head that I might have problems running fish tape through a rigid plastic conduit with a few bends. Guess it is not usually a problem, otherwise it would be widely documented - or it may have been just my dumb luck, but...

Turned out that a wide and big 1" conduit run of 26ft with two 90° bends is not passable in either direction.

Took me a split second to realize why - the bell. The one that is at one end of each conduit component. The rest should be obvious.

Two conclusions:

• Do a dry run - works pretty well with plastic conduit, it holds up pretty well and you can probably get away with running it through even though it's not glued together yet;
• Plan ahead and remember that you may not be able to pass a conduit in one direction.

What did I end up with? Well... Had to cut the elbow out and reverse the direction. Don't be like me.

Fake Air Returns: Watch Out

I remember reading a post at HVAC-Talk a few years ago when someone wrote that a contractor just cut a hole in drywall, installed a return air grill and claimed that it is exactly what it is supposed to be - a return. Long and heated discussion followed (HVAC-Talk expires threads, so the source is no longer available), with polar opinions being a) yes, it's acceptable and b) not at all, you must provide the path.

I've seen grills leading to dead spaces a few times afterwards, which makes me think this is not an exception.

Now that I'm learning framing - well, turns out that the building code explicitly calls for installing what is called fire blocking: two-by stud material that runs horizontally from stud to stud - every 10 ft measured vertically in stud bays. Fire blocking interrupts the upward flow of flames and heat.

Two lessons:

1. There is no easy way to install an air return in a room;
2. There is no easy way to wire anything - studs (at the minimum) are horizontal obstacles, fire blocking (at the minimum) are vertical obstacles.

TANSTAAFL.

SketchUp + HVAC-CALC, part 2

You've read it here first. Now someone closer to the subject area implemented it: Energy Analysis Tool for SketchUp.

Told you.

Random Notes: Timing and Blueprints

Random note #1: One thing I have not regretted, in a hindsight, that I've started the wiring project right now - in local mid-season. When the insulation is disturbed, it doesn't function properly anymore, and had this happened in the middle of the summer (or in the middle of the winter for those farther North), it would've been bad.

Random note #2: SketchUp is the best thing since sliced bread for DIY projects. More and more professionals are starting to realize the importance of it (see the article on timber framing, for example). It works for project at almost any scale - the house model I've built, for example, has everything from the yard on the top of the scale to individual screws in places where I've laid conduit, on the bottom of it. Start with 3d Warehouse (Thai House Blueprints is a beautiful example), don't forget the SketchUp Blog.

The Great Wiring Project, part 4

The Great Wiring Project, part 1
The Great Wiring Project, part 2
The Great Wiring Project, part 3

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This one is going to be really short: I thought I'd be able to get away without a patch panel. No such luck. Off looking for one. Suggestions welcome.

(to be continued)