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Clothes Dryer (What You Need To Know)

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There are over 9 million clothes dryers in households across Canada. Over 1 million of these are not being vented to the exterior. Many more that are believed to be vented to the exterior are either not or are not properly installed to do so. Most homeowners are keeping their dryers from 10 years up to 20 years. This can be a long time for a dryer to remain in operation without proper installation and maintenance. Clothes dryers are one of the most misunderstood and misused appliance in our home. We use them every day and like many other conveniences in our lives, we take them for granted. But taking this appliance for granted can be very costly in terms of money, property and lives. A cloth dryer is usually a 220V appliance on a 30 amp service, itís no electrical slouch. In the U.S. there are between 13,000 and 15,000 dryer related fires annually causing many deaths. Property damage and loss is estimated at $100 million. To help prevent you from being added to this statistic ATI has gathered valuable and comprehensive information on clothes dryer operates in relations to your home. These include the dangers associated with using this appliance, maintenance information, safety tips (to help you get the most out of your dryer), helping you save money & property, and, most important, staying safe. Remember, the buck stop with you so get the most out of you dryer. To get the most value out of your clothes dryer, and operate it safely at the same time, requires only a little knowledge and understanding. Be knowledgeable and be proactive.

Energy Usage
Clothes dryers consume energy on two levels. One, the energy the dryer needs to operate. Second, the heat energy it exhaust from your home while itís operating. This will also include the cost of energy for cooling your home (HVAC systems) in the summer.
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Air Flow
One must first understand that a cloth dryer operates by drawing a lot of air into the front of the unit, and exhaust that air to the exterior. A regular household dryer will typically process about 240 CFMís (240 cubic foot of air per minute). The intake air comes from the interior of your home (usually warm air) and the air is then replaced with air (exterior air) drawn into the dwelling from many areas of your structure envelope. Your dryer requires a steady flow and a large volume of air to operate efficiency. This means it must also be able to replace this high volume of air it exhausts. If your dryer does not get the air it needs it will operate inefficiently and this will cost you money, or worst. Most people underestimate the thousands of cubic feet of air that are exhausted by a dryer each time it dyes just one load of clothes. ATI recommends talking to the experts and donít hesitate to search the web for information on clothes dryer fires, safety issues and maintenance procedures.

To help put CFM rate of a dryer into perspective and understandable terms we will look at how much air and how often this air is processed through your dryer. These values are approximate only and will differ by dryer CFM rates, household size, duct work, and structural characteristics. A regular clothes dryer will exhaust approximately 240 CFMís. CFM rates are usually related to capacity; the higher the capacity the higher the CFM rating. If you live in a home that is 2,000 square feet with 8 foot walls you will have approximately 16, 000 cube foot of air space (2000 X 8 = 16,000). If your dryer is rated at 240 CFMís your dryer will take approximately 67 minutes to replace all the air in your home (16,000 / 240= 67 minutes). Each dryer load will take approximately 60 minutes to dry. Therefore, the air in your home will be replaced approximately every hour or load of laundry. For higher CFM rated dryers it will take less time than smaller CFM dryers to change the volume of air in your home. The larger your home the longer it will take to exhaust this air with the same dryer but the more space you have to reheat. A larger dryer in a smaller home will result in more of a cooling effect unless the heat is increased to compensate for it. Loosing heat through your dryer is usually not a big issue in the summer (unless you are trying to keep your interior air cool) but does have its biggest effect felt during the heating season.
Have some fun with these numbers. Gets the CFM rating for you dryer (documents or from the manufacture), and washroom exhaust and stove exhaust units. All these should be exhausting to the exterior. If they are not exhausting directly to the exterior you should plan to correct this oversight as soon as possible. Get the square footage of your home (measure the outside length and width of your home or look at your real estate documents) and calculate the cube space (as above). Do your calculation for each unit and play with them a bit. You will get a good idea of what it costs to keep water vapor form ruining your day and how much heat is being exhausted out of your dwelling. Convenience costs so try to maximize your efforts by recouping some of the wasted energy. You will see why a little bit of knowledge, time and effort can help save you money and headaches in the long run.
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Buying a Dryer
When buying a clothes dryer talk to a repeatable dealer or a manufacture about which type of dryer and duct work is best for your space (basement, closet, apartment, etc.). Get several recommendations from several sources. When purchasing a dryer always choose one with a good energy efficiency rating, cool down cycle and moisture sensors. A moisture sensor will automatically stop your dryer when the clothes are dry. This little feature is a very good energy saver and will help prolong the life of your unit. You can also look at purchasing front end washer and dryer. Front loading units use less energy than conventional models.
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Operating a Dryer
When operating a clothes dryer keep the area around the unit clear of obstructions and materials, especially in front of the dryer where it draws its air supply. Leave a good space behind the dryer as well. Some people insist on moving their unit as close as possible to the wall. The result is a crushed duct pipe that will restrict air flow from the dryer and resulting obstruction point for lint buildup and possible fire hazard. Add to this the resulting inefficiency of the unit costing you extra energy and drying time, and lower the life expectancy of the unit. Donít overload your dryer either as it will not run efficiently (extra weight wearing machine parts, increasing drying time, and volume of materials restricting air flow) and, once again, this it will help lower the life expectancy of your appliance.
Closing off your dryer into a small space (room) is not a good idea either because youíre dryer needs good air flow. Open all interior doors and allow your dryer to get a good air supply so it can work efficiently. You can even install ventilated doors to the dryer room so your appliance can get the air it needs. When you allow your dryer a good air supply you will probably notice that it causes a cooling effect in your home over several loads especially on cool days, this is normal. When closing your dryer into a small or single room you may notice that that room will get warm. This may be the result of your dryer operating inefficiently and possibly running hot due to the restricted air source. Your clothes will also take longer to dry and you will use more energy in the process.
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Duct Work (Venting)
Along with proper air flow there are two other very important elements to consider for a worry free operation of your dryer; Ďproper duct installationí and Ďlent buildup preventioní. Both are generally misunderstood and these, combined with air flow restriction concerns, are the major leading cause of higher energy consumption, lower life expectancy of your unit, and the cause of fires in clothes dryers and duct systems. The proper venting of your dryer is very important. The best venting is a short straight metal duct venting directly to the exterior. But this is not always possible. The first best source for dryer duct installation is in the owner manual and instructions that comes with your unit. This information should contain information on preferred duct to use (ridged smooth metal duct (best) or flexible duct (second and last) with a diameter suited to your dryer), and the maximum configuration (maximum lengths, bends and 90-degree fittings) for that duct system. Never use plastic exhaust duct, it not only increases drying time but is flammable. Foil looking duct is not much better. Both can be damaged easily which will release water vapor into your home. Do not use screws to fit pipes together, the screw shafts inside the piping can collect lint and the air flow through the duct can cause friction on the screw which can be like striking a match to kindling (lint).

If you are installing the duct system you may need to perform some calculations and know the proper installation requirements for your needs. Even if you are hiring someone to do this for you, you still need to know this information. You need to make sure whoever is performing this task is doing their job properly. You would not be the first to have a system installed where the installers knew next to little about proper and safe installation practices. You would not be the first to discover that your duct work contained a lot of unnecessary bends and elbow, and terminated inside your crawl space or attic. Donít install the duck system without taking all elements of proper installation into consideration. A single 90-degree fitting on a 4 inch pipe usually equals 10 feet of straight pipe. The longer the duct work and the more bends and corners, the more inefficient your dryer will operate and the greater risk of lint buildup somewhere in the system. Donít look at adding extra duct to fit a dryer in a covenant or desired space. Fit, where possible, the dryer to the most efficient space close to an exterior wall. Building a new home or renovating; allow for a proper placement and installation for this valued workhorse in your plans.
When installing duct work make sure your exterior vent is not to close to the ground. Keep your exterior vent free from snow buildup around the unit. Check to make sure the dryer vent flaps are not freezing shut or sticking (especially in winter). Always vent to the exterior, do not vent high humidity units (dryers, washroom exhaust, etc.) anywhere in the interior of your home for any reason. It is ok to vent straight up through the roof to the exterior. Make sure your dryer (and other high humidity units) is not venting through the soffit, into the attic, or into your crawl space. Clothes dryers generate a lot of water vapor and you do not want this water vapor condensing in your walls or attic. Do not vent this exhaust into a crawl space. This moisture can not only cause serious structural damage but will result in mold. There is no safe or right way to vent moisture into your home.
If you do install duct work through you roof remember to well insulate the piping if it is passing through a cool space (crawl space, attic, etc) on its way to the exterior. If the pipe is not well insulated, water can condense on the inside of the vent causing leaks or poor dryer performance especially if the pipe starts to fill with water. This water, if left to build up, can cause a total obstruction in your system. With longer vertical duct lengths expect extended drying time and a lower life expectancy on your unit.
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Along with good air flow and proper duct work you only need to know the proper care and maintenance needed for your dryer to run at, or near, peak efficiency, and run trouble free for a long time. One of the biggest issues with clothes dryer is lint buildup in the unit and in the duct system. This will restrict air flow that will not only make your dryer run inefficiently but run hotter. Now consider the fact that lint is a highly flammable material. Lint accumulates and reduces airflow which then feed on each other to provide the right conditions for a fire. Lint and restricted air flow are home-made ingredients in a fire starter recipe. Protect yourself against the hazards and high energy costs of an inefficient cloth dryer system.

It is recommended that the lint tray be cleaned out before and after each load. This is to insure that the try is cleaned between loads. As you know from cleaning out the lint tray, your dryer produces a large amount of link. This is not all the lint your dryer produces. Lint will end up in to the exterior environment and some remain in you dryer and duct system. You should remove the lint tray periodically and vacuum inside and around the tray housing (at least once every 2-3 months for normal use). Every fall (the winter season is the hardest on our dryer system) remove the duct form the rear of the dryer and vacuum out the exhaust port and vent hose (if your duct system is very long and/or contains a lot of bends and elbows you may not be able to do a very good job of cleaning it out without taking it apart). Make sure there is no obstruction anywhere in the line.
You can periodically check the outside dryer vent while the dryer is operating to make sure exhaust air is escaping and escaping at a good velocity. A regular clothes dryer with a short duct 4 inch diameter line will exhaust air at approximately 50 km/hr. To familiarize yourself with this air flow you can periodically put your hand under the exterior vent hood. If it is not producing good velocity, the vent or the exhaust duct may be partially blocked. If there is little or no air flow shut down the dryer immediately and check for the cause. Disconnect the duct from the dryer and test the air flow coming from the dryer. This will help tell you if itís the dryer or duct system thatís at fault.
Inside the dryer housing should be cleaned as well. In Canada it is recommended that all North American style clothes dryers be cleaned on the inside by a qualified appliance technician every 2 to 3 years. Pull out the dryer occasionally to vacuum away any
lint behind and underneath the dryer. A clean dryer lasts longer, saves money and reduces the risk of fire.
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Improper venting or a clogged vent will give the following signs
  • Long drying time
  • Clothes are hot at the end of the cycle; this is bad for Perma-Press clothes.
  • Dryer is noisier than normal; new dryers should run reasonably quite.
  • Automatic sensor fails to shut off dryer; water vapor is not being exhausted properly from the dryer.
  • Damage (premature wear) or failure of heating elements, motor, or bearings.

If your dryer is properly installed, you are performing regular maintenance checks on your units, and you are following recommended procedures for its usage; it should run trouble free for a long time.
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Dryer Tips
  • When drying only one or two item, toss in a few items of varying sizes to promote good tumbling action and improve drying results. Always try to use a medium size load in your dryer
  • Drying rack that sit on the front and rear bulkheads of your dryer help speed the drying process of items like; caps, sneakers, sweaters, stuffed toys and pillows. You can ask your dealer for details and availability.
  • Raising the dryer 6-12 inches of the floor with a storage drawer. You will have to do less bending (easier on your back) and have a handy out of sight storage space for all your washing/drying needs. The only downside is aesthetics; the top of you dryer will not be in-line with the top of the washer. Raising your top loading washer is not really an option. If you have front end washer/dryer combo you can look at raising these units off the floor for extra height and storage space. If you use a raised platform make sure itís sturdy and your washer/dryer will not move around the top of the unit.
  • Use an outdoor clothesline where possible. This will help save even more energy and your clothes can smell a lot better without static cling. Remember there has never been a report of a clothesline fire. If you have I bet it had nothing to do with energy issues, air flow restrictions or lint buildup. If you use a clothes line inside you may need to have a dehumidifier in that room, especially in winter. The water from the drying clothes has to go somewhere.
  • Laundry can also be dried outside even in the winter when the temperature is well below freezing. First the laundry will freeze and become stiff. Then the frost on the clothes will sublimate (changing from a solid (water) to a gas (vapor)) into the air leaving the items relatively dry. The downside is that this can take much longer than indoor drying. You also have keep an eye on the weather and you will have do a little more planning especially if you live in an area where the weather can change rapidly. Although it takes longer to dry clothes outside in the winter you will use more energy (dryer operation and heat loss) drying clothes indoors. Even a combination of both will help cut energy costs in your home.

Safety Tips
  • Never leave the dryer running while you are out of the house.
  • Keep a fire extinguisher near your dryer and easily accessible (not behind the unit)
  • Install a fire detector near your dryer. Replace the batteries of all fire detection units at the same time each year, and test them several times a year. The fall is a good time for this necessary task.
  • Take special care when drying clothes that have been soiled with volatile chemicals such as gasoline, cooking oils, cleaning agents, or finishing oils and stains. If possible, pre-soak and wash the clothing more than once to help minimize the amount of volatile chemicals on the clothes and, preferably, hang the clothes to dry. If using a dryer, use the lowest heat setting and a drying cycle that has a cool-down period at the end of the cycle. To prevent clothes from igniting after drying, do not leave the dried clothes in the dryer or piled in a laundry basket. Wash these clothes separately and try smelling them after each wash to help detect if they are still producing chemical odors (off-gassing). Drying them outside is the safest option.
  • Avoid using liquid fabric softener on all-cotton clothing made of fleece, terry cloth, or velour. In flammability tests, liquid fabric softener added to rinse water accelerated the burning speed of these fabrics when ignited. If you want a softener and less hazardous clothes, use dryer sheets instead.
  • Buy dryers that use moisture sensors rather than ordinary thermostats to end the auto-dry cycle. Thermostats can allow the dryer to run longer than necessary. Occasionally wipe the moisture sensor with a soft cloth or cotton ball and rubbing alcohol to keep it functioning accurately. Sensors are usually located on the inside of the dryer, just below the door opening, and can be hard to find. They are usually two curved metallic strips, shaped somewhat like the letter "C" (review your owner manual).

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