How long should a dryer vent be?
The maximum length of a dryer vent should not exceed 25 feet. Sounds simple enough, right? But there’s a little more to it than that. You must consider every elbow too. And as far as air resistance goes, every elbow is equivalent to 5 feet of straight venting. Let me give you an example. Let’s say your dryer vent has 10 feet total of straight venting and two elbows, that would be equal to 20 feet: 10ft + 2 elbows (5ft + 5ft) = 20 feet. In that example you would be under the maximum. Make sense?
So now that we know how long a dryer vent should be, “Why does it matter so much?”, is the next logical question. It matters because the small blower motor in your dryer can push that wet, sometimes heavy, lint only so far, and if the dryer vent is too long or has too many elbows that lint will accumulate much faster causing clogs and a potential fire hazard. Now I bet you’re saying, “But I empty my lint basket every time I use my dryer, shouldn’t that prevent any lint from accumulating?”. Even though that is a great discipline to have and I commend you if you do clean the basket every load, unfortunately the lint basket itself does not stop all the lint your clothes produce. A lot of the lint does get past the basket and then accumulates in the vent and also the undercarriage. Unless you have a short run with minimal elbows, your dryer vent is bound to get lint accumulation. This is not to say that the short ones don’t accumulate lint– they do. It’s just that a shorter run will take longer to get dirty than a longer one. The best rule of thumb to follow when venting a dryer is– the shortest length possible with the least amount of elbows.