A Hidden Enemy: Dryer Lint

Don't laugh. Dryer lint. It causes more problems than you think. If you have rental units with washer/dryer hookups, or you provide washer and dryer, there are some cautions for you to be aware of. This week a fire in Birmingham, Alabama that destroyed 23 apartment units was caused by a clogged dyer vent (clogged with lint, of course). This was not an isolated incident. A study from 2000-2004 by the National Fire Prevention Association showed that there were 8,900 dryer fires a year (nearly all caused by lint buildup) in the U.S. There are other problems that cost you money, though, from dryer lint.

One very nasty one is when there is a break in the vent line and lint is sent directly under the house. The problem is that your furnace intake is likely nearby and will suck that lint right in. Then it gets into the fan and the coils and you've got another big problem. Your unit will work too hard and may shut down from overheating. This can also cause your tenant's heating/cooling bill to rise and leave them in a pinch to pay the rent. Cleaning the lint out of the fan and coils is costly and time-consuming. Not doing this, though, will shorten the life-span of your furnace. Now we're talking serious dollars.

Another odd problem we've seen from lint back ups: defrost lines on refrigerators. We have some small apartments where we supply the washer and dryer. Of course the tenants take full advantage, and often don't clean the lint every time they use the dryer. We then started getting calls about refrigerators not working properly, such as water forming inside the refrigerator or them not cooling. What we found was the defrost drain lines were getting clogged. Modern refrigerators will briefly heat the freezer section in order to melt the frost and ice buildup up. Long ago, you just had to take everything out every so often and let it melt. There is a drain line to take this water to a location where it can simply evaporate, usually a pan below the refrigerator. When the drain lines clog, that water has no where to go and will either pour into the refrigerator from the freezer or refreeze in the line, backing everything up. Water in the air (measured by humidity) will condense on objects when cooled (notice what happens to the outside of a glass of ice water). Raindrops form around dust particles in the atmosphere. Dryer lint is perfect for this. At the end of the line that goes into the freezer, the water will condense and then freeze around lint particles and block the line.

We've also seen the problem in the condensation lines for air conditioning. Poor design caused the drain line and the dryer to be next to each other. Lint gets in the line until it blocked up completely and the water that condenses around the cool parts of the central air unit has no where to drain. Then the tenant calls saying water is coming from their utility closet - often thinking they have a leak in the washing machine.

Sending someone to unclog these lines won't necessarily bankrupt you, but it's one more cost, aggravation and danger you can live without. What you can do:

1) Emphasize to tenants how important it is they clean the lint from the dryer filter every single time they use it. Write it into the lease, put signs on the dryer reminding them (if you own the dryers), when you change the furnace filters and it seems the filter is gathering a lot of lint, ask the tenant if they've been cleaning the lint filter on the dryer as they should. Be firm on this and if they don't understand why, explain the dangers and problems to them.

2) Check the vent and lines yourself every year or so. If you see lint/dust accumulating in the crawl space, you likely have a break in the line. Also, if you have a flexible line, look for sags and repair those (lint will gather in the low spots and clog the line).

3) If you have the type of flexible line that looks like it's a foil but when you touch it, it feels crinkly like dry plastic, replace it. Even though it was nearly a standard just a few years ago, it really is plastic, and easily gets breaks or catches on fire. Many areas have changed their building codes to make this stuff illegal, and it voids the warranties on new dryers to hook them up to it.

4) The most critical point is the place where the vent plate meets the vent line at the floor. If you get a clog here then it's close to the dryer, where the vented air is the hottest. This point takes a lot of heat/abuse, so replace the plate if there is damage, even if there isn't a clog yet. We've seen a lot of clogs at this point.

5) If you want a very simple test, just have the dryer turned on and check to see if there is good air flow out of the vent outside. If it's weak, you've got blockage somewhere. Another thing, you can ask your tenants if it's taking a long time for their clothes to dry; it's a symptom of clogging.

6) If you have concerns, the lines can be cleaned, either by professional or you can purchase the brushes and run them yourself.

Living units are supposed to be designed so that the distance from the dryer to the exterior is short and straight - the longer the line and the more turns it makes the more potential problems - but home designers have gotten away from that standard. If you have units with long lines or ones with multiple turns, be more vigilant. While only about 2% of residential fires are cause by dryer vent blockages, it's one of the more preventable fire causes for a landlord, and the other maintenance headaches that lint can cause make a few minutes of checking the lines a good investment.