Fire Hazard Alert - Is Your Dryer Ready to Ignite

Home
>
Home Improvement
>
Fire Hazard Alert - Is Your Dryer Ready to Ignite

Fire Hazard Alert - Is Your Dryer Ready to Ignite

In recent years there has been many stories about dryers catching on fire. Should we be concerned? Yes of course. We should take seriously anything that may put our family at risk.

Was the problem the dryer? Rarely. After investigating it is usually determined to have been the venting within the home catching on fire, and not the dryer.

Obviously appliance manufacturers are concerned about the possibility of any dryer related fires. They have made it a policy to advise both service companies and consumers that the use of plastic venting is prohibited. They have also begun issuing cautions not to exceed suggested maximums for venting length. Let me try to explain the details of this problem.

The drying process

When clothes are being dried inside your family dryer there are two processes happening. Firstly, heat is applied to the air inside the dryer drum as it turns. This raises its internal temperature to approximately 175 Fahrenheit causing moisture to be driven out of the clothes by evaporation. Secondly, large amounts of air is passed through the clothes. Surprisingly, the real trick to efficiently dry clothes is not the heat, but rather this vast volume of air.

Ever wonder why the clothes on the clothesline dry so fast on a windy day? The hero is the wind. Well, the same process takes place inside your family dryer.

To make them dry faster air is constantly blown through the clothes during the drying cycle. The tumbling action of the drum further exposes the clothing to the hot air flow. While they tumble the air picks up moisture from the clothes, carries it down the venting, and dumps it outside the home. Most people think the venting is to push the lint outside. Actually, its primary purpose is to dump the moisture outside the home.

It is a process that works efficiently. That is, as long as nothing is allowed to interfere with it. Impede, slow down, or stop the airflow and the process quickly fails.

In the past homeowners who wanted to vent their dryers did it using rigid sections of venting. The sections were secured together (using screws or duct tape), and elbows were added if necessary, to connect the dryer and venting to the wall outlet. Although time consuming to install, straight venting sections were durable and would often outlive the dryer. This was in the era when laundry equipment always sat in the basement, against an outside wall.

Then along came flexible plastic venting. It made installations easier. It turned an hour installation into a ten minute job. The flex though tended to become brittle and break easily. Also it was prone to blockage and needed to be replaced every few years. But since plastic venting was more convenient we continued with its use.

Then came a change in lifestyle. As both parents went off to work the household dryer was moved to accommodate our faster paced lifestyle. To save us time it was moved from the basement to a ground floor laundry room. Although moved to the working level of the home, it was still close to an outside wall.

So you are saying, "I know all this, but what does it have to do with venting fires".

I answer, "Have patience, we are almost there".

Taking this desire for easy access still further the dryer was moved again.

The laundry room is now often located near the centre of the home, close to the family room or kitchen. If located upstairs it is often centrally located between the bedrooms, allowing faster access to where most dirty laundry is produced. Easier for the homeowner that is, but no longer near an outside wall. The distance from the dryer to an outside wall of the home is now substantially farther than it used to be.

Presto, we have come to the crux of our problem. The venting is too darned long.

Physics and the venting pipe

It is a lot more difficult to push air down a long venting pipe than a short one. This is because air inside the pipe has weight and volume. Obviously, the air inside a longer pipe would weigh more than a shorter one.

After about twenty feet of venting pipe the dryer begins having difficulty pushing against all this weight. The average dryer motor does not have enough strength to overcome the weight of the air inside the pipe. The result is that the air in the pipe begins to slow down.

Since the air slows down the moisture accumulates in the venting rather than being carried outside. This causes the venting interior to become wet and lint traveling through the pipe will cling to this wetness.

This starts a vicious cycle within the venting pipe. It goes something like this: The more lint in the venting, the more blockage; More blockage means slower air flow; Slower air flow means more moisture in the venting; More moisture in the venting means more lint.

I think you understand the scenario now.

Taken to extremes the lint can block the venting closed. When this happens it can cause the dryer to overheat. The normal drum temperature of 175 Fahrenheit can quickly shoot up to 300 Fahrenheit or higher. It may even get hot enough to allow lint in the venting to ignite. If a fire of this type starts within flexible plastic venting it can quickly burn through the venting and allow the fire to spread.

Therefore, remove any flexible plastic venting and replace with rigid, straight sections. If the total length is less than fifteen feet, flexible "metal venting" is acceptable.

Calculating true venting length

So lets look at how we can determine if a venting problem is in our future.

Manufacturers generally suggest a venting length of 15 feet (and two elbows) to be the maximum. But the true venting length can be deceptive.

"So how do I know if my venting is too long"?

The true length of your venting is determined as follows:

1. Measure all the straight lengths and add them together

2. Count all the turns or elbows and multiply this number by 4

3. Add up the totals

Example Since an elbow or turn is equivalent to an additional 4 feet of pipe 20 feet of venting with 4 turns would actually be:

20 feet + 4X4 feet = 36 feet

Don't be surprised by the true equivalent length of your venting. In modern homes it can be substantially longer than the manufacturers suggested maximum.

If the blockage becomes critical the dryer will stop doing its job properly. As a homeowner watch for the following signs that the venting may be starting to block.

· Clothes coming out wet
· Excess lint left on clothes at cycle end
· Inside of dryer feels wet
· Taking too long to dry a load
· Clothes very hot at end of cycle
· Electrical consumption greatly increased

Summing up

"So who is to blame for this problem"?

I say there is no culprit in this scenario. If you want to blame anything, blame our fast paced lifestyle. Gone are the times when laundry day was a full days work. We all want instant gratification and instantaneous results - even with our laundry chores.

So as a consumer what can you do to alleviate this problem? Well you certainly can't move the laundry room. The best thing you can do is to be aware that the problem exists. Consider taking down the venting and cleaning out the lint buildup during your annual spring cleaning. Also, regularly walk outside and check the vent cap where it exits your house. Remove any lint buildup and make sure the flap moves freely. If you see a lot of activity from birds in you backyard check it immediately. They love to build nests inside the vent cap.

Other than the previous suggestions a little common sense might avert a tragedy. Do not operate your dryer while asleep, out of the house, or next door at the neighbours. And always remember the old saying that states "better safe than sorry".

About the Author
Copyright 2004 by Donald Grummett - All right reserved.
Donald Grummett is an appliance service manager in Ottawa, Canada. In the trade over 30 years as both a technician, business owner, and technical trainer. For more information about appliances including FAQ, Stain guide, Recycling, and Newsletter visit http://www.mgservices.ca

In The News:

Yahoo! News: Top Stories

Gaza fighting rages despite cease-fire proposal (AP)

AP - Israel resumed its Gaza offensive Wednesday, bombing heavily around suspected smuggling tunnels near the border with Egypt after a three-hour lull to allow in humanitarian aid. Hamas responded with a rocket barrage. Despite the heavy fighting, strides were made on the diplomatic front with the U.S. throwing its weight behind a deal being brokered by France and Egypt.

Obama taps spending watchdog, eyes Social Security (AP)

AP - Pointing with concern to "red ink as far as the eye can see," President-elect Barack Obama pledged Wednesday to tackle out-of-control Social Security and Medicare spending and named a special watchdog to clamp down on other federal programs Â— even as he campaigned anew to spend the largest pile of taxpayer money in history to revive the sinking economy.

Senate Democrats yield to Obama, retreat on Burris (AP)

AP - Senate Democrats beat a hasty retreat Wednesday from their rejection of Roland Burris as President-elect Barack Obama's successor, yielding to pressure from Obama himself and from senators irked that the standoff was draining attention and putting them in a bad light. Burris said with a smile he expected to join them "very shortly."

Feds say inauguration attractive terrorist target (AP)

AP - The upcoming inauguration of Barack Obama is an attractive target for international and domestic terrorists, but U.S. intelligence officials have no information about specific threats to the Jan. 20 event.

Obama hails `extraordinary' moment with presidents (AP)

AP - Confronting a grim economy and a Middle East on fire, Barack Obama turned Wednesday to perhaps the only people on the planet who understand what he's in for: the four living members of the U.S. presidents' club.

Melting snow causes heavy flooding in Wash. state (AP)

AP - Rain and high winds lashed Washington state Wednesday, causing widespread avalanches, mudslides, flooding and road closures as the heavy snowfall that has buried parts of the state began to rapidly melt.

Drug made from genetically engineered goats may become scientific first (AP)

AP - You've heard of making cheese from goats' milk, but prescription drugs? In what would be a scientific first, an anti-clotting drug made from the milk of genetically engineered goats moved closer to government approval Wednesday after experts at the Food and Drug Administration reported that the medication works and its safety is acceptable.

People's Choice Awards have heroic odds (AP)

AP - "The Dark Knight" could soar away with several trophies Wednesday night at the 35th annual People's Choice Awards. The Batman film will vie for awards in such categories as favorite cast, action movie, on-screen matchup and superhero.

Pa. man opens neighbor's door with chain saw (AP)

AP - An eastern Pennsylvania man may face up to 37 years in prison for tearing open a neighbor's door with a chain saw. Police say 34-year-old Robert Kane began sawing through the front door of Jamie Zaleski's apartment in Scranton while Zaleski and several friends ran out the back.

AP source: Browns to hire Eric Mangini as coach (AP)

AP - Eric Mangini is the new head coach of the Cleveland Browns, a week after being fired by the New York Jets. A person with knowledge of the negotiations told The Associated Press that Mangini will be introduced Thursday at a news conference at the team's headquarters in Berea.

Israel pounds Gaza again (Reuters)

Reuters - Israeli aircraft and tanks pounded the Gaza Strip on Wednesday and troops battled Palestinian guerrillas on the ground as U.S. backing for a proposed truce raised expectations of an end to the 12-day-old offensive.

Budget deficit to hit $1.2 trillion in fiscal 2009 (Reuters)

Reuters - The U.S. budget deficit will swell to a record $1.186 trillion in fiscal 2009, congressional forecasters said on Wednesday, the result of an economic recession that has cut tax receipts and caused massive government bailouts of banks and automakers.

Senate Democrats move to seat Burris (Reuters)

Reuters - In an abrupt switch, Democratic leaders began talks on Wednesday to swear in Roland Burris, appointed by embattled Illinois Gov. Rod Blagojevich to replace President-elect Barack Obama in the U.S. Senate.

Union gears up for negotiations with GM and Chrysler (Reuters)

Reuters - United Auto Workers bargaining teams are arriving this week in Detroit as the union gears up for negotiations with General Motors Corp and Chrysler LLC, which are mandated to cut labor costs under a $17.4 billion federal bailout.

Mumbai-like attack could happen in U.S.: Bush aide (Reuters)

Reuters - U.S. cities are vulnerable to an attack like the gun-and-grenade assault that terrorized Mumbai for three days and killed 179 people, the White House homeland security adviser said on Wednesday.

"Enemy combatant" will be early test for Obama (Reuters)

Reuters - The case of Ali al-Marri, accused of being an al Qaeda "sleeper" agent and held for 5-1/2 years at a U.S. military prison in South Carolina, will be an early test for President-elect Barack Obama.

Salmonella outbreak sickens 388 across U.S.: health officials (Reuters)

Reuters - An outbreak of salmonella food poisoning has made 388 people sick across 42 states, sending 18 percent of them to the hospital, U.S. health officials said on Wednesday.

U.S. presses to jail Madoff on diamonds, watches mail (Reuters)

Reuters - Accused swindler Bernard Madoff should be jailed for violating a court order by mailing $1 million worth of diamonds, watches and other jewelry to friends and family, U.S. prosecutors told a court on Wednesday.

Israel approves tougher war on Hamas (AFP)

AFP - Israel on Wednesday approved an even tougher war on Hamas, warning residents to flee southern Gaza ahead of planned bombing of cross-border tunnels, as the Palestinian death toll passed 700.

Kremlin lays down terms as gas crisis engulfs Europe (AFP)

AFP - Russian President Dmitry Medvedev on Wednesday laid down terms for a resumption of Russian gas shipments via Ukraine to Europe as tens of thousands of Europeans suffered heating cuts amid freezing weather.

Fire Hazard Alert - Is Your Dryer Ready to Ignite

Home Improvement Home Improvement