Straight dryer duct run vs leaving a little slack - what do you all do?

I definitly went the tight, near-straight route for mine. When I replaced the venting on my older Maytag last year, I kept the run as close to a plumb line as possible. The primary goal has to be volume and velocity of the exhaust, not keeping the hose from rattling when you push the drum around.

My biggest concern was how much the dryer actually heats up, and that's directly related to duct efficiency. Any bends, even gentle ones, create backpressure. That backpressure forces the heat and moisture to linger in the cavity, which equals longer drying times and more likely lint accumulation inside the duct, which is a fire risk. I even measured the run, trying to minimize the bends because I knew the semi-rigid duct, even though it's flexible, is going to fight you if it has too much slack. I used a quick measurement tool and found the ideal space between the outlet and the wall was only a few inches, so even the straightest piece still needed a bit of allowance, but I cut the slack out til the hose was firm and secure. That felt much more right.

If you are worried about vibration, securing the clamps tightly and ensuring the dryer sits perfectly level is a better fix than allowing extra hose length to create unnecessary elbows.

I had a diferent experiance when I tackled this project on my house. I was dealing with a older high-efficiency dryer, so my primary focus wasn't just speed, but making sure I wasn't creating any resistance at all. The straight shot approach sounds great in theory, but if the angle is off by even a couple of degrees, you get turbulence that kills your airflow efficiency over time. I went with a slightly longer path, but instead of letting it have a big loop, I tried to keep the changes in direction as subtle and gradual as possable.

My main worry was that even if the duct is tight, a sudden sharp turn can create back pressure. I remember when I finished the install, the vent flap felt slightly less 'snug' than I would have liked, but after running my annual performance check, my heat cycle times were actually better than before I replaced it. The slight deviation prevented that kind of pressure spike. If you are using rigid metal instead of flexible foil, the rules definitely change. With rigid duct, you want minimal bends because those elbows are rigid and they increase the resistance significantly. On the foil, you have more forgiveness, but I'd still err on the side of smooth curves rather than trying to force a tight angle.

Semi-rigid is the way to go if you can, honestly. The foil stuff tears so easy when you're shoving the dryer back, and it sags into wierd shapes over time. The semi-rigid holds its shape once you bend it, so you can form that gentle curve and it'll actualy stay put instead of kinking shut. I did mine a couple years ago and also made a habit of popping the outside hood open now and then to make sure it's not caked with lint. That's usally the real bottleneck, not the duct behind the machine. But yeah, snug with just enough slack so the clamps aren't strained works fine in my experience.

One thing that helped me was strapping the duct to the wall stud halfway down the run. My vent sits about 14 feet from the dryer, and I learned the hard way that even a snug install can get shoved around when the machine walks during a spin cycle. A plastic cable clip or two holds the semi-rigid in the exact shape you formed, so the clamp never takes the tug and the curve never collapses when you scoot it back. I also put the dryer on the smooth side of the flooring with a scrap of hardboard under the front feet so it slides easier and doesn't drag the whole connection with it.

The thing that made the difference for me was a hard 90 degree elbow that plugs right into the dryer outlet. My vent hood is offset from the exhaust too, and I kept fighting the flexible duct trying to make both turns in one piece. Once I put a rigid elbow on the machine side, the flexible section only had to handle the final little jog to the wall and it basicly held its own shape. I also do the tissue test at the outside hood every few months, hold a square of toilet paper up to it while the dryer runs and see if it gets sucked flat. Quick way to catch a sagging duct before it becomes a lint problem.