Home & Garden
Clothes dryers seem innocuous enough but actually, it turns out that they’re killers. More accurately, I should say, they’re arsonists, because they cause about 15,000 fires a year.
The problem is that lint doesn’t get captured adequately at lint traps and manages to build up in vent lines and can eventually catch fire. Lint is terribly flammable you know. I had this great idea recently (see how rich I am from all my great ideas?) to collect lint, add a little paraffin and roll it into logs for the fireplace. Yeah, it is a bad idea. Oh well.
Long dryer vents are worse than short ones when it comes to collecting lint and starting fires. There are also a range of other issues also make one vent more trouble than another. I know I’m weird but I actually find this really fascinating.
Modern codes limit the length of dryer vents to around 25 feet total length. The old length was 14 feet and somehow things got safer recently. I don’t get it, really. This total length is reduced by any bends because bends create friction and diminish the capacity of the dryer to push the lint to the outdoors. A 90 degree bend should decrease the total length by five feet and a 45 degree bend decreases the total by two and a half feet. As you can see, vents get quite a bit shorter very fast when you make a few turns.
The code doesn’t say anything about vents that rise but I believe that this is serious matter as well. One of the goofiest things I’ve ever seen is a built-in-place dryer vent that goes up through the roof. These are guaranteed to clog as the weight of lint continues to drag it down where it will rest and clog lower in the system. These become even more dangerous because you can’t see them or notice when they’re getting full of lint.
Something that the code does say is that dryer vents need to be made up of smooth material since corrugated piping is a lint collector. All those ridges help the little fibers to grab on and pretty soon you’re all clogged up. By the way, if the clothes are still damp after an hour, this could be the reason (a clogged vent).
Another thing that captures lint is a screw that’s used to connect two lengths of dryer vent. Again, the trusty code book says no to screwing these vent pipes together for just this reason. Personally, I like metal foil tape for these connections. Be sure to use four-inch smooth metal ducting and place the male ends facing away from the dryer and toward the outside so that they can’t catch lint either.
When installing a dryer vent, it’s also a good idea (and a requirement) that the vent be well secured in place. Finish your installation with a hood and a damper (a little flapper to keep the bad things outside). There can’t be any screen in the system and if the reason for that isn’t obvious, you need to go back and start this article over again.
In short, a dryer vent should be short, straight, not go up any more than absolutely necessary and be as smooth as possible. I can’t tell you how often I’ve seen a dryer that was placed near an outside wall but had some elaborate Rube Goldberg device running through the crawlspace to somewhere in France when they could simply have gone right through the wall and made things simpler, cheaper and safer.
By the way, there are now these cool brushes you can stick on your drill that whisk out even lengthily or circuitous dryer vents and I’d say that this is a very nice idea for the truly safety conscious person with entirely too much time to spare. The Quick-Clean dryer vent brush system (I saw this at hartshearth.com) is a nice looking example.
Now, that’s all very nice but it’s not actually what I want to talk about today. This is.
So, I’m looking at this condo about two years ago and I get to the laundry closet. You know, there aren’t any more laundry ROOMS now, there’re all closets with just enough room for a stacked pair about six-feet high. Well, that’s fine but this particular one has no dryer vent. I pointed this out as a deficiency and the realtor calls me back a day or two later and says that the builder has an exemption from this requirement because they’re going to use ventless dryers. I say that there is no such thing and swear on a stack of bibles and my mother’s wedding band and a troop of midget acrobats. Well, guess what? (you guessed!). Yes, Darleen, there is a ventless clothes dryer.
So how in the world does this work? It works through condensation. In fact, these are now referred to as condensing dryers. By running the damp hot air that normally exits a dryer through a cooling cycle (usually using cooler room air although water can also be used) the moisture in the air reaches dew point and turns back into liquid water which is then captured in a vessel or run to a drain. This process can save energy because the hot air is cycled back into the dryer via a separate loop rather than going out the vent on a conventional dryer.
There are other kinds of dryers coming along including heat-pump dryers and steam compression dryers. These hold the promise of lower energy cost and quicker dryer time but for now, the condensation dryer seems to be our intrepid lead.
The reason to buy these is the same as our friend, the developer of that condo would have. That being that the dryer ended up being located where a vent would be too long or otherwise too difficult to manifest.
Years ago, as a lad, I traveled to England. As my journey proceeded and my rucksack became increasingly fragrant, I found myself in a London laundromat. Having finished a load of wash, I began placing my clothes in a dryer when a rather frumpy but cheerful woman stepped up and said, “Here then, darlin’, you don’t want to waste all that money now, do you?” and began stuffing my wet clothing into a small, weighty, cylindrical machine. “Use the extractor, then, won’t you?, It’s free.” And it was. The extractor was a high power wringer that, in a minute or two, removed about 90 percent of the water from the clothing so that the drying would take only a small fraction of the time that the dryer alone would have required. English energy costs have always been high compared to ours and they’d seen what we readily overlook; that it’s cheaper to run a motor and spin clothes than it is to boil the water out of them. Still, a heating process (or dehumidification) is still needed to finish up. These are used in the U.S. today but only in large laundry processes (and, of course, that little one at the gym for your swim suit).
Clearly, there’s a lot to think about with dryers but I’ll leave you with a last thought and I hope this one will be the one to linger. Anyway you look at it, dryers cost energy and require mining (for the metals) and drilling for oil or coal. They add CO2 to the atmosphere and cost money to operate. Clothes lines are cheap and the sun and wind are free. Also, clothes dried this way last longer, since they’re literally burning up just a little bit every time you put them through the dryer.
There’s so much more to say on this topic but this will have to do for today. Thanks for listening. Sometime I just need to vent.