PLEASE DO NOT MOVE DRYER CLOSER TO REAR WALL.(Part 3) Dryer Vent Safety

 

PLEASE DO NOT MOVE DRYER CLOSER TO REAR WALL. (Part 3) Dryer Vent Safety

In this series I have included this article (which is reproduced with permission) from my professional association; InterNACHI.  I’m reprinting it with a view to providing some of the reference data for the earlier articles that home owners and renovators can use to understand and plan laundry room and exhaust vent installations.

It will also give people a perspective on why inspectors will be talking about this problem whereas it was not only a few years ago.

Wall note

Dryer Vent Safety    by Nick Gromicko, Rob London and Kenton Shepard

Clothes dryers evaporate the water from wet clothing by blowing hot air past them while they tumble inside a spinning drum. Heat is provided by an electrical heating element or gas burner. Some heavy garment loads can contain more than a gallon of water which, during the drying process, will become airborne water vapor and leave the dryer and home through an exhaust duct (more commonly known as a dryer vent).

 A vent that exhausts moist air to the home exterior has a number of requirements:

1.            It should be connected. The connection is usually behind the dryer but may be beneath it. Look carefully to make sure it’s actually connected!

2.            It should not be restricted. Dryer vents are often made from flexible plastic or metal duct, which may be easily kinked or crushed where they exit the dryer and enter the wall or floor. This is often a problem since dryers tend to be tucked away into small areas with little room to work. Vent hardware is available which is designed to turn 90° in a limited space without restricting the flow of exhaust air. Restrictions should be noted in the inspector’s report. Airflow restrictions are a potential fire hazard!

3.            One of the reasons that restrictions are a potential fire hazard is that, along with water vapor evaporated out of wet clothes, the exhaust stream carries lint – highly flammable particles of clothing made of cotton and polyester. Lint can accumulate in an exhaust duct, reducing the dryer’s ability to expel heated water vapor, which then accumulates as heat energy within the machine. As the dryer overheats, mechanical failures can trigger sparks, which can cause lint trapped in the dryer vent to burst into flames. This condition can cause the whole house to burst into flames! Fires generally originate within the dryer but spread by escaping through the ventilation duct, incinerating trapped lint, and following its path into the building wall.

inferno

 InterNACHI believes that house fires caused by dryers are far more common than are generally believed, a fact that can be appreciated upon reviewing statistics from the National Fire Protection Agency. Fires caused by dryers in 2005 were responsible for approximately 13,775 house fires, 418 injuries, 15 deaths, and $196 million in property damage. Most of these incidents occur in residences and are the result of improper lint cleanup and maintenance. Fortunately, these fires are very easy to prevent.

The recommendations outlined below reflect International Residential Code (IRC) SECTION M1502 CLOTHES DRYER EXHAUST guidelines:

M1502.5 Duct construction. Exhaust ducts shall be constructed of minimum 0.016-inch-thick (0.4 mm) rigid metal ducts, having smooth interior surfaces, with joints running in the direction of air flow. Exhaust ducts shall not be connected with sheet-metal screws or fastening means which extend into the duct.

This means that the flexible, ribbed vents used in the past should no longer be used. They should be noted as a potential fire hazard if observed during an inspection.

M1502.6 Duct length.

The maximum length of a clothes dryer exhaust duct shall not exceed 25 feet (7,620 mm) from the dryer location to the wall or roof termination. The maximum length of the duct shall be reduced 2.5 feet (762 mm) for each 45-degree (0.8 rad) bend, and 5 feet (1,524 mm) for each 90-degree (1.6 rad) bend. The maximum length of the exhaust duct does not include the transition duct.

This means that vents should also be as straight as possible and cannot be longer than 25 feet. Any 90-degree turns in the vent reduce this 25-foot number by 5 feet, since these turns restrict airflow.

 

A couple of exceptions exist:

1.            The IRC will defer to the manufacturer’s instruction, so if the manufacturer’s recommendation permits a longer exhaust vent, that’s acceptable. An inspector probably won’t have the manufacturer’s recommendations, and even if they do, confirming compliance with them exceeds the scope of a General Home Inspection.

2.            The IRC will allow large radius bends to be installed to reduce restrictions at turns, but confirming compliance requires performing engineering calculation in accordance with the ASHRAE Fundamentals Handbook, which definitely lies beyond the scope of a General Home Inspection!

M1502.2 Duct termination.

 Exhaust ducts shall terminate on the outside of the building or shall be in accordance with the dryer manufacturer’s installation instructions. Exhaust ducts shall terminate not less than 3 feet (914 mm) in any direction from openings into buildings. Exhaust duct terminations shall be equipped with a backdraft damper. Screens shall not be installed at the duct termination.

Inspectors will see many dryer vents terminate in crawlspaces or attics where they deposit moisture, which can encourage the growth of mold, wood decay, or other material problems. Sometimes they will terminate just beneath attic ventilators. This is a defective installation. They must terminate at the exterior and away from a door or window! Also, screens may be present at the duct termination and can accumulate lint and should be noted as improper. 

M1502.3 Duct size.

The diameter of the exhaust duct shall be as required by the clothes dryer’s listing and the manufacturer’s installation instructions.

Look for the exhaust duct size on the data plate.

M1502.4 Transition ducts.

Transition ducts shall not be concealed within construction. Flexible transition ducts used to connect the dryer to the exhaust duct system shall be limited to single lengths not to exceed 8 feet (2438 mm), and shall be listed and labeled in accordance with UL 2158A.

 In general, an inspector will not know specific manufacturer’s recommendations or local applicable codes and will not be able to confirm the dryer vent’s compliance to them, but will be able to point out issues that may need to be corrected.

 

 

Original blog post on ActiveRain: Link to Blog Post

“House Herpes” Invasion of the bed biters!

 

Bed Bugs: Inspecting for the New “House Herpes”

by Nick Gromicko and Rob London 
Bed bugs are small, flightless, rust-colored parasites that feed on the blood of humans and other warm-blooded animals. Inspectors should learn the telltale signs of these pests and be capable of providing information to their clients.Adult bed bug

Bed bugs were diminished to an historical footnote after their near-eradication in the 1950s, but they are re-emerging in a big way. At the EPA’s National Bed Bug Summit in 2009, researchers decided that the parasite’s revival is more appropriately termed a pandemic rather than an epidemic, noting its rapid spread across large regions and different continents. For those afflicted by the bug, humiliated and defeated by its persistence, many prefer to refer to the infestation as “house herpes.” The United States has seen a 50-fold increase in bed bug infestations over the last five years, according to the National Pest Management Association. An entomologist told MSNBC, “It’s like the return of the wooly mammoth,” as many of his peers had previously never seen a single bed bug in their careers. The outbreak has affected most parts of North America and Europe, especially in urban areas.

Researchers believe bed bugs have roused from a half-century of hibernation for two reasons:  the termination of the use of the pesticide DDT; and a rise in international travel. DDT, a powerful synthetic pesticide, was used widely in agriculture until a public outcry concerning its safety lead to a US-ban of the chemical in 1972, followed by international bans. Unbeknownst to the environmentalists of the time, these laws would permit future outbreaks to grow unchecked, which is precisely what happened when travel increased from countries where bed bugs were never subjugated, such as India.

Hotbeds of international travel, such as New York City, have hosted the bulk of the carnage. The bugs hitch rides from country to country in suitcases, and creep into hotel rooms where other guests are then exposed and unknowingly spread the parasites to movie theatres, cabs, buses, hospitals, houses, and everywhere in between. In New York City, bed bug reports increased 800% from 2008 to 2009, a year in which the Department of Housing Preservation and Development received 13,152 bug infestation complaints.Bed bug bites

The unpleasantness of a typical rodent or insect extermination is largely the fee charged by the exterminator.  But with bed bugs, this fee is just one piece of a greater nightmare. Because bed bugs are adept at hiding almost anywhere, an alarming quantity of possessions, from curtains to books and picture frames, must be discarded or quarantined. In one posh New York City rental tower, a tenant was forced to part with carpets, bedding, curtains, 20 cashmere sweaters, an Armani suit, a couch, a headboard, a night table, a bedframe, and an exercise bike, according to the New York Daily News. Other victims have had to throw away their books unless they were willing to inspect each one, page by page. Some possessions may be salvaged if they are sealed in special casing long enough for the bed bugs to die, which can takes many months. During this time, residents may be forced to move to temporary housing elsewhere.

Fortunately, the health dangers posed by bed bugs seem to be limited to temporary skin irritation and inflammation, akin to mosquito bites. There are no known cases of disease transmission from bed bugs to humans, despite the fact that the parasites seem similar to other parasites that do transmit disease, such as fleas and ticks. Anaphylactic shock, however, may be experienced by a small percentage of the population, and measures should be taken to prevent bacterial infection of bitten areas.

Adult bed bugs are flat, apple-seed sized with rusty-colored, oval bodies. Newly hatched bed bugs are semi-transparent, light tan in color, and the size of a poppy seed. Yet, due to their elusive nature, their presence is usually discovered through peripheral clues rather than by seeing the bugs themselves. Some of these signs include fecal spots, blood smears, crushed bugs, or the itchy bumps that may result from bites. Bugs may be disturbed while feeding and leave a cluster of bumps, or they may bite in a row, marking the path of a blood vessel. The parasites emit a characteristic musty odor, although the smell is sometimes not present in even severe infestations. The bugs also emit a smell that is detectable by dogs, which has lead to the implementation of dogs in bed bug detection. Properly trained dogs can find bed bugs in wall voids, furniture gaps, and other places that humans may overlook and, in doing so, they focus on the area in which exterminators must spray.Bed bugs, their eggs and excrement

It is best for bed bugs to be treated by pest management professionals (PMPs), not homeowners, as there is risk that an inexperienced person may spread the infestation further throughout the home. For instance, bug bombs will be ineffective and merely spread bed bugs. Even chemical sprays designed to kill bed bugs, if used by inexperienced homeowners, may make the infestation worse. PMPs can inspect for bed bugs in their immature stages of development, including their eggs, while homeowners cannot. In addition, prep work performed by a homeowner may make it difficult for the PMP to assess the extent of the infestation.
The following tactics may be useful, however, for temporary relief or confirmation of the presence of bed bugs:
  • Remove bed skirts, as they provide easy access for the bugs to travel from the floor to your bed. If you must have bed skirts, make sure they do not reach the floor.
  • Move your bed away from the wall. Bed bugs cannot fly, but they can climb walls in order to fall onto the bed.
  • Place furniture legs in tin cans coated with talcum powder, petroleum jelly or a non-evaporative liquid, to deter the bugs from climbing.
  • Place a strip of duct tape at the base of furniture with the sticky side out. This tactic can be used to confirm the presence of bed bugs because it will trap them in place.
  • Spray cracks and crevices with an insecticide designed to control bed bugs. Follow the label’s directions carefully. However, do not treat bedding, towels or clothing with insecticide.

Homeowners can limit their chances of bed bug exposure by purchasing only new furniture, as stowaway bugs can hide in older or used chairs and mattresses. Hostels, hotels and motels host many travelers and are obvious breeding grounds for bed bugs, and many hostels ban sleeping bags for this reason. Unfortunately, person-to-person contact is difficult to avoid.
In summary, bed bugs are a growing, serious threat.  Along with wood-destroying organisms, inspectors may want to enhance their knowledge by learning to recognize and become familiar with the problems posed by bed bugs because of their potential to infest homes and damage property.
N.B. I’ve reposted this article ( with permission) for public health reasons. As our childhood phrase goes “Sleep tight, don’t let the bed bugs bite”.

 

 

Original blog post on ActiveRain: Link to Blog Post