A central vacuum system (sometimes called a whole-house vacuum system) is a cleaning device installed throughout a building. Located in the garage or basement, a canister receives dust and debris sucked by the force of a motor from wall outlets, which are located for the homeowner’s convenience.
 
While many Americans are unfamiliar with central vacuums, they are not new inventions; the idea dates back as far as the 1850s in Sweden, where horse-powered fans were used to create suction through in-wall plumbing. Horses were later replaced by servants, who pumped giant bellows or pedaled stationary bicycles, until electric motors eventually took over. Shortly thereafter, however, portable vacuum cleaners became available, and central vacuum systems were largely forgotten due to their relative expense. Their hibernation ended by the 1990s when growing house sizes and concerns over air quality combined with the availability of cheaper plastic piping, more powerful motors and refined filtration systems. Yet, even today, American homes are dependent on portable vacuum cleaners, in contrast with Canadian and Scandinavian homes, where central vacuum systems are more common. 
 
Central vacuum systems boast some advantages over portable units, some of which are as follows:

• They are long-lasting. Their motors can handle more usage than typical portable units. Warranties, too, are usually longer for central units. 
• They are quiet. Because the motor is located outside the living area, users are not subjected to noise created by the motor, which can be excessive and stressful. 
• They can be retrofitted into older houses, or built into new construction.
• They are a good investment. Just as a kitchen renovation or new deck will make a home more valuable, many buyers will pay extra for a house equipped with a central vacuum. 
• They are hypo-allergenic. Unlike portable vacuums, which recycle air back into the room, dust-laden air is blown into the outdoors from central vacuum systems. One comprehensive study conducted at the University of California at Davis' School of Medicine compared portable to central units and concluded that “a central vacuuming system would best provide [allergen removal] as it would be installed outside the living area of the dwelling and/or vented outdoors." 
• The system is easy and safe to use. There is no heavy equipment to carry from room to room, and no electric cords to trip over or catch on furniture.

Types of central vacuum cleaners available include:

• cyclonic, in which air is spun in a canister and exhausted to the outdoors. Location is critical for these units, as it is possible for exhausted, debris-laden air to find its way back into the house through open windows. The filter must be removed and cleaned periodically; 
• inverted filter, in which the dirt enters the vacuum canister amidst a tornado-like swirl of air. The canister must be emptied periodically, and always outside of the home. Allergy sufferers may find disposal unpleasant, as mold and other debris become airborne; and 
• disposable bag, in which dirt is sucked into a paper bag in the same fashion as for portable units. This is perhaps the cleanest and most hygienic method available, as mold spores, bacteria and other debris are physically separated and stored in a bag from which they cannot escape.

The disadvantages of central vacuum systems include:

• price. A good system can cost $1,500, which is significantly more expensive than even premium portable vacuum cleaners;
• damage caused by items sucked up inadvertently. With greater power comes higher risk that large items will be sucked up, potentially causing damage to the unit. Tales abound of units becoming jammed or broken when they swallow, often at the hands of children, broken jars of jelly, toilet water, and even pet birds. Portable units are usually too weak to readily suck up items that can cause them to break;  
• a system compromised by weak suction.  Such a problem may be due to obstructed pipes or exhaust, an excessively dirty filter, or a full canister that needs to be emptied. If the unit does not operate at all, the motor might be broken, a breaker may have tripped, or the wiring may be defective.

In summary, central vacuum systems are convenient, powerful and expensive home-cleaning devices.

Humidifiers are devices that humidify air so that building occupants are comfortable. Central humidifiers are hard-wired into a house’s plumbing and forced-air heating systems. 
 What is humidity? 
Humidity refers to the amount of moisture in the air. “Relative humidity” signifies the amount of moisture in the air relative to the maximum amount of water the air can contain before it becomes saturated. This maximum moisture count is related to air temperature in that the hotter the air is, the more moisture it can hold. For instance, if indoor air temperature drops, relative humidity will increase. 
How do central air humidifiers work?
Central air humidifiers are integrated into the forced-air heating system so that they humidify air while it is being heated. The water that is used by the device is pumped automatically into the humidifier from household plumbing, unlike portable humidifiers, which require the user to periodically supply water to the device. Humidifiers are available in various designs, each of which turns liquid water into water vapor, which is then vented into the house at an adjustable rate. 
Why humidify air?
Certain airborne pathogens, such as those that cause the flu, circulate easier in dry air than in moist air. Moist air also seems to soothe irritated, inflamed airways. For someone with a cold and thick nasal secretions, a humidifier can help thin out the secretions and make breathing easier.
Indoor air that is too dry can also cause the following problems:

• damage to musical instruments, such as pianos, guitars and violins; 
• dry skin; 
• peeling wallpaper; 
• static electricity, which can damage sensitive electrical equipment, cause hair to stick up, and can be painful or annoying; and  
• cracks in wood furniture, floors, cabinets and paint.

Central Humidifier Dangers
Humidifiers can cause various diseases. The young, elderly and infirm may be particularly at risk to contamination from airborne pollutants, such as bacteria and fungi. These can grow in humidifiers and get into the air by way of the vapor where it can be breathed in. Some of the more common diseases and pathogens transmitted by humidifiers are:

• Legionnaires’ Disease. Health problems caused by this disease range from flu-like symptoms to serious infections. This problem is generally more prevalent with portable humidifiers because they draw standing water from a tank in which bacteria and fungi can grow; 
• thermophilic actinomycetes. These bacteria thrive at temperatures of 113° to 140° F and can cause hypersensitivity pneumonitis, which is an inflammation of the lungs; and  
• “humidifier fever,” which is a mysterious and short-lived, flu-like illness marked by fever, headache, chills and malaise, but without prominent pulmonary symptoms. It normally subsides within 24 hours without residual effects.

Other problems associated with humidifiers include:

• accumulation of white dust from minerals in the water. These minerals may be released in the mist from the humidifier and settle as fine white dust that may be small enough to enter the lungs. The health effects of this dust depend on the types and amounts of dissolved minerals. It is unclear whether these minerals cause any serious health problems; 
• moisture damage due to condensation. Condensed water from over-humidified air will appear on the interior surfaces of windows and other relatively cool surfaces. Excessive moisture on windows can damage windowpanes and walls, but a more serious issue is caused when moisture collects on the inner surfaces of exterior walls. Moisture there can ruin insulation and rot the wall, and cause peeling, cracking or blistering of the paint; and 
• accumulation of mold. This organic substance grows readily in moist environments, such as a home moistened by an over-worked humidifier. Mold can be hazardous to people with compromised immune systems. 

Designs and Maintenance

• drum-type humidifier:  has a rotating spongy surface that absorbs water from a tray. Air from the central heating system blows through the sponge, vaporizing the absorbed water. The drum type requires care and maintenance because mold and impurities can collect in the water tray. According to some manufacturers' instructions, this tray should be rinsed annually, although it usually helps to clean it several times per heating season. 
• flow-through or “trickle” humidifier:  a higher quality though more expensive unit than the drum-type, which allows fresh water to trickle into an aluminum panel. Air blows through the panel and forces the water to evaporate into the air stream. Excess water exits the panel into a drain tube. This design requires little maintenance because the draining water has a “self-cleaning” effect and, unlike the drum-type humidifier, there is no stagnant water.

Other tips that InterNACHI inspectors can pass on to their clients:

• If equipped with a damper, it should be closed in the summer and opened in the winter. The damper may appear as a knob that can be set to “summer” or “winter” setting, or it may be a piece of metal that can be inserted to cover the duct opening. 
• The humidifier is controlled by a humidistat, which must be adjusted daily. Some new models do this automatically, although most require daily attention from building occupants. The humidistat should contain a chart that can be used to identify the proper setting based on the outdoor temperature. If this adjustment is not performed, condensation will likely collect on cool surfaces and potentially lead to mold or wood rot. Many homeowners do not know that this calibration is necessary. 
• The furnace might need to be checked for rust. Some humidifiers are installed inside the plenum of the furnace, which can be damaged by rust if the humidifier leaks. 
• Central humidifiers may have a solid core that should be replaced each year. The manufacturer’s instructions should be consulted regarding this replacement.

In summary, central humidifiers are used to humidify air to make it more comfortable, but they can cause health problems and building damage if they are not properly maintained.

A building's central air-conditioning system must be periodically inspected and maintained in order to function properly. While an annual inspection performed by a trained professional is recommended, homeowners can do a lot of the work themselves by following the tips offered in this guide.
 
Clean the Exterior Condenser Unit and Components
 
The exterior condenser unit is the large box located on the side of the building that is designed to push heat from the inside of the building to the outdoors. Inside of the box are coils of pipe that are surrounded by thousands of thin metal "fins" that allow the coils more surface area to exchange heat. Follow these tips when cleaning the exterior condenser unit and its inner components -- after turning off power to the unit!

• Remove any leaves, spider webs and other debris from the unit's exterior. Trim foliage back several feet from the unit to ensure proper air flow.
• Remove the cover grille to clean any debris from the unit's interior. A garden hose can be helpful for this task.
• Straighten any bent fins with a tool called a fin comb.
• Add lubricating oil to the motor. Check your owner’s manual for specific instructions.
• Clean the evaporator coil and condenser coil at least once a year.  When they collect dirt, they may not function properly.

Inspect the Condensate Drain Line
 
Condensate drain lines collect condensed water and drain it away from the unit.  They are located on the side of the inside fan unit. Sometimes there are two drain lines—a primary drain line that’s built into the unit, and a secondary drain line that can drain if the first line becomes blocked. Homeowners can inspect the drain line by using the following tips, which take very little time and require no specialized tools:

• Inspect the drain line for obstructions, such as algae and debris. If the line becomes blocked, water will back up into the drain pan and overflow, potentially causing a safety hazard or water damage to your home.
• Make sure the hoses are secured and fit properly.

Clean the Air Filter

 
Air filters remove pollen, dust and other particles that would otherwise circulate indoors. Most filters are typically rectangular in shape and about 20 inches by 16 inches, and about 1 inch thick. They slide into the main ductwork near the inside fan unit. The filter should be periodically washed or replaced, depending on the manufacturer’s instructions. A dirty air filter will not only degrade indoor air quality, but it will also strain the motor to work harder to move air through it, increasing energy costs and reducing energy efficiency. The filter should be replaced monthly during heavy use during the cooling seasons. You may need to change the filter more often if the air conditioner is in constant use, if building occupants have respiratory problems,if  you have pets with fur, or if dusty conditions are present.  
 
Cover the Exterior Unit
 When the cooling season is over, you should cover the exterior condenser unit in preparation for winter. If it isn’t being used, why expose it to the elements? This measure will prevent ice, leaves and dirt from entering the unit, which can harm components and require additional maintenance in the spring. A cover can be purchased, or you can make one yourself by taping together plastic trash bags. Be sure to turn the unit off before covering it. 
Close the Air-Distribution Registers
 
Air-distribution registers are duct openings in ceilings, walls and floors where cold air enters the room. They should be closed after the cooling season ends in order to keep warm air from back-flowing out of the room during the warming season. Pests and dust will also be unable to enter the ducts during the winter if the registers are closed. These vents typically can be opened or closed with an adjacent lever or wheel.  Remember to open the registers in the spring before the cooling season starts.  Also, make sure they are not blocked by drapes, carpeting or furniture.
 
In addition, homeowners should practice the following strategies in order to keep their central air conditioning systems running properly:

• Have the air-conditioning system inspected by a professional each year before the start of the cooling season.
• Reduce stress on the air conditioning system by enhancing your home’s energy efficiency. Switch from incandescent lights to compact fluorescents, for instance, which produce less heat.

 
In summary, any homeowner can perform periodic inspections and maintenance to their home's central air-conditioning system.

A fan attached to a room’s ceiling is known as a ceiling fan. Like other fans, it is used to provide comfort for building occupants by circulating air within a room. 
 Fun Facts About Ceiling Fans

• An adult human cannot be decapitated by a ceiling fan, according to the TV show "MythBusters."  A powerful, industrial-strength fan might be able to damage a skull or slice a person’s neck, however. 
• Ceiling fans were first used in the United States in the 1860s. They were powered by a system of belts driven by a stream of running water. 
• Unlike air conditioners, fans do not actually cool the air, which is why they merely waste electricity when they circulate air in an unoccupied room.

Ceiling Fan Components
A ceiling fan is comprised of the following parts:

• electric motor:  varies with the size of the fan and its application; 
• blades:  typically, two to six spinning, precision-weighted blades made from metal, wood or plastic; industrial fans typically have three blades, while residential models have four or five; 
• blade irons:  connect the blades to the motor; 
• safety cable: on heavy fans, these are required to hold the fan in place in case the support housing fails; 
• flywheel:  connects the blade irons to the motor; 
• ceiling mount:  designs include ball-in-socket and J-hook; 
• downrod:  used where ceiling fans are suspended from high ceilings; 
• motor housing:  protects the fan motor from dust and its surroundings; may also be decorative; and 
• lamps: may be installed above, below or inside the motor housing.

Common Fan Defects

• The fan falls. A ceiling fan that breaks free from its ceiling mount can be deadly. Fans must be supported by an electrical junction box listed for that use, according to the National Electric Code, and a fan brace box will need to be installed. While a particular junction box might support a fully assembled fan, during operation, it will exert additional forces (notably, torsion) that can cause the support to fail. Homeowners often overlook this distinction by carelessly replacing light fixtures with ceiling fans without upgrading the junction box, which should clearly state whether it’s rated to hold a ceiling fan. 
• The fan wobbles. This is a common and distracting defect that is usually caused when fan blades are misaligned from one another. Specific problems stem from minute differences in the size or weight of individual blades, warping, bent blade irons, or blades or blade irons that are not screwed in tightly enough. The ceiling mount may also be loose. Wobbling is not caused by the ceiling or the particular way that the fan was mounted. Wobbling will not cause the fan to fall, and there have been no such reports. Wobbling can, however, cause light fixture covers or shades to loosen and potentially fall. These items should be securely attached, with all screws tightly set in place. An easy way to tell if the blades are not on the same plane is to hold a yardstick or ruler against the ceiling and measure the distance that the tip of each blade is from the ceiling by manually pushing the blades. A homeowner can carefully bend the misaligned blade back into place. Blades can also be corrected in this way if measurement reveals that they are not equidistant from one another.  
• There is inadequate floor-to-ceiling blade clearance. No part of the fan blades of a residential ceiling fan (usually having four or more blades) should be closer than 7 feet from the floor in order to prevent inadvertent contact with the blades. Downward air movement is maximized when the fan blades are around 8 or 9 feet from the floor. For high ceilings, the fan may be hung to a desired height. Low-profile fan models are available for ceilings that are lower than 8 feet from the floor. Also, fan blades should be at least 18 inches from walls. For commercial ceiling fans (usually having three blades), no part of the fan blades should be closer than 10 feet from the floor in order to prevent inadvertent contact with the blades.  Underwriters Laboratories UL 507 Section 70.2.1 says: 
  
  "The blades of a ceiling-suspended fan shall be located at least 3.05 m (10 feet) above the floor when the fan is installed as intended."

Underwriters Laboratories makes exceptions if the fan blade edges are thick and the fan is turning slowly.

• Blades are turning in the wrong direction. In the winter months, the leading edge of the fan's blades should be lower than the trailing edge in order to produce a gentle updraft, which forces warm air near the ceiling down into the occupied space below. In the summer, the leading edge of the fan's blades should be higher as the fan spins counter-clockwise to cool occupants with a wind-chill effect. On most models, the fan direction can be reversed with an electric switch located on the outside of the metal housing, but the same effect can be achieved on other models by unscrewing and remounting the fan blades. 
• An indoor fan is not designed for exterior use. Ordinary indoor ceiling fans are unsafe to use outdoors or in humid environments, such as bathrooms.  They will wear out quickly. Fans that are rated “damp” are safe for humid environments, but they, too, should never be used where they might come into contact with liquid water. Only fans that are rated “wet” are safe for such use, as they incorporate features such as all-weather, UV-resistant blades, sealed motors, rust-resistant housing, and stainless steel hardware.

In summary, properly installed and maintained ceiling fans can inexpensively cool or warm building occupants.

Home inspectors are often asked by their clients if they should have their home tested for radon. Real-world loss-of-life comparisons help consumers decide about whether or not they should test. If you are worried about shark attacks, getting trampled by cows, or terrorism, you should be worried sick about radon. These statistics help put things in their proper perspective so that your clients can decide if they want a radon test or not.  Here is a downloadable PDF that inspectors can give to their clients onsite to help them decide if they should get a radon test:  https://www.nachi.org/documents2012/radon-deaths-chart.pdf
 

 DEATHS PER YEARNumber
CauseSource
 611,105  Heart Disease -Centers for Disease Control (2015)
 584,881  All Cancers -Centers for Disease Control (2015)
 160,000  Smoking -American Cancer Society (2004)
 88,000  Alcohol Use- Centers for Disease Control (2015)
 51,783  Colon Cancer -Centers for Disease Control (2015)
 40,290  Breast Cancer -National Cancer Institute (2015)
 41,149  Suicide -Centers for Disease Control (2014)
 32,719  Motor Vehicle Accidents -Insurance Institute for Highway Safety (2013)
 29,500  Falls -National Safety Council (2013)
 22,767  Prescription Drug  Overdoses -National Institute on Drug Abuse (2013)
 21,840  Leukemia U.S.- EPA (2010)
 21,530  Lymphoma U.S. -EPA (2010)
 21,000  Lung Cancer from Radon Gas U.S. -EPA
16,121   Homicides -Centers for Disease Control (2013)
 14,775  Illegal Drug Overdoses -National Institute on Drug Abuse (2013)
 13,712  AIDS -Centers for Disease Control (2012)
11,208   Firearm Homicides Centers for Disease Control (2013)
 8,257  Heroin Overdoses -National Institute on Drug Abuse (2013)
 4,944  Cocaine Overdoses -National Institute on Drug Abuse (2013)
 3,880  Drowning -Centers for Disease Control (avg. 2005-2009)
 3,005  Fires -U.S. Fire Administration (2011)
 3,000  Secondhand Smoke  -U.S. EPA
 2,500  Choking -National Safety Council (2009)
 1,690  Thyroid Cancer -U.S. EPA (2010)
 630  Bicycle Accidents  -National Safety Council (2009)
 618  Excessive Heat -Centers for Disease Control (avg. 1999-2010) 
606   Firearm Accidents -Law Center to Prevent Gun Violence (2010)
 376  ATV Accidents -National Safety Council (2009)
 300  Ladder Falls -International Association of Certified Home  Inspectors
170   Carbon Monoxide -Consumer Product Safety Commission
 104  Wind (including tornadoes) -National Oceanic and Atmospheric  Administration  (2012)
 100  Scalding Tap Water -Johns Hopkins Bloomberg School of Public  Health  (2013)
 100  Bee Stings -Boston Children's Hospital 
 72  Terrorist Attacks -FBI (avg. 1970-2015)
 26  Lightning -National Oceanic and Atmospheric Administration  (2014)
 20  Dangerous Cows -Centers for Disease Control (2009)
 15  Falling Icicles- Death in Society Research Foundation
 12  High School and College  Football Injuries -National Center for Catastrophic Sports Injury  Research (2013)
 2  Vending Machines Accidents -U.S. Consumer Product Safety Commission
 1  Shark Attacks -Mother Nature Network (2012)
 0  Marijuana Overdoses -Numerous sources
 0  Nuclear Power Plant Leaks -Numerous sources

Carpeted bathrooms are bathrooms that have carpeted floors instead of traditional floor surfaces, such as tile or vinyl. Despite their tendency to foster mold and bacteria, carpets are sometimes installed in residential bathrooms for aesthetic purposes. Carpets should never be installed in bathrooms in commercial buildings.
 
Advantages of Carpets in Bathrooms

• They make bathrooms appear more warm and inviting. 
• They are softer than tile and many people find them comfortable on bare feet. 
• Bathroom slip hazards are reduced. It is easier to slip on hard bathroom surfaces, such as tile, than on carpet. 
• Installation is generally quick and inexpensive.

Disadvantages of Carpets in Bathrooms
 
The pad beneath the carpet may soak up large amounts of moisture.  Some of the common ways that carpets may come into contact with moisture in bathrooms include:

• Steam from the shower will condense on the carpet.
• Water splashes from the tub or shower.
• Water sheds from shower/tub occupants as they step onto the carpet.
• Water splashes out of the sink.
• Water drips from the vanity.
• Water leaks from the toilet. 

The presence of moisture in the pad will lead to the growth of decay fungi on the wood or oriented strand board (OSB) sub-floor. The sub-floor will be decayed and weakened by mold. Mold also releases spores that can cause respiratory ailments, especially for those with certain health problems. Inspectors can use moisture meters to determine if there is excess moisture beneath a carpet.
 In addition to potential mold growth beneath the carpet, bacteria can accumulate in carpeting that surrounds the toilet. Bacteria are contained in urine, which can be accidentally deflected onto the carpet.


Carpeted Bathrooms in Commercial Buildings
 
It is against code to install carpet in commercial bathrooms. The 2007 edition of the International Building Code (IBC) states the following concerning carpeted bathrooms in commercial buildings:
In other than dwelling units, toilet, bathing and shower room floor finish materials shall have a smooth, hard, nonabsorbent surface. The intersections of such floors with walls shall have a smooth, hard, nonabsorbent vertical base that extends upward onto the walls at least 4 inches (102 mm).
Recommendations for Clients
 
The following are recommendations that InterNACHI inspectors can pass on to clients who are experiencing urine- or moisture-related problems with their bathroom carpet:

• Clean the carpet regularly to remove any mold or urine that may be present. 
• Keep the carpet as dry as possible. Various devices exist that prevent water from bypassing the shower curtain. 
• Install a bathroom fan, if one is not installed already. If a fan is installed, operate it more often. 
• Inspectors can inform their clients about why they are experiencing problems.

In summary, carpets installed in bathrooms can trap moisture and urine, substances that can cause structural damage and health problems.

The Dangers of Mold
Molds produce allergens, which are substances that can cause allergic reactions, as well as irritants and, in some cases, potentially toxic substances known as mycotoxins.  Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals.  Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis).  Allergic reactions to mold are common.  They can be immediate or delayed.  Molds can also cause asthma attacks in people with asthma who are allergic to mold.  In addition, mold exposure can irritate the eyes, skin, nose, throat and lungs of both mold-allergic and non-allergic people.  Symptoms other than the allergic and irritant types are not commonly reported as a result of inhaling mold, but can also occur.
Carpet at Risk
Carpeting is an area of the home that can be at high risk for mold growth.  In order to grow, mold needs moisture, oxygen, a food source, and a surface to grow on.  Mold spores are commonly found naturally in the air.  If spores land on a wet or damp spot indoors that contains dust for them to feed on, mold growth will soon follow. Wall-to-wall carpeting, as well as area rugs, can provide an ample breeding ground for mold if conditions are right.  At especially high risk for mold growth are carpeting located below ground level in basements, carpet in commonly moist or damp climates, and carpet that has been wet for any period of time.  
Identifying Mold in Carpeting
Just because mold is not immediately apparent or visible on a carpet's surface does not mean that mold growth is not in progress.  In fact, mold will probably only be visible on the surface of carpets in unusually severe cases of growth, such as carpet damaged in flooding that has remained wet for some time.  The following are some examples of identifiable instances where mold growth has occurred or is likely to occur:

• visible mold growth:  As stated above, this can be a rare case, but sometimes it may be obvious from visual inspection that mold growth is occurring.  Carpet in this condition is most likely not salvageable and should be disposed of and replaced.  Often, even if mold growth is not visible on the top of carpeting, it may be occurring underneath the carpet where it can't be easily seen.  Carpet suspected of containing mold should always be examined on both sides.
  
  
• carpet mildew:  Any discoloration or odor on carpeting that might be described as mildew is probably a case of mold.
  
  
• wet or water-damaged carpet:  Any carpet that has been subjected to water damage from flooding or standing water will most likely need to be disposed of.  Conditions are ripe for mold growth, in this case.  Even if visibly apparent mold growth has not yet begun, it is highly likely to happen unless the carpet is completely removed, cleaned and dried within 24 to 48 hours.  Even then, removal and cleaning are not guaranteed to prevent mold growth.  It is more likely that the carpet will need to be replaced.
  
  
• wet padding beneath carpet:  If padding beneath the carpet has become wet for any reason, or has become moist from condensation, the padding as well as the carpet on top are at risk for mold growth.  The padding may need to be replaced, as will the carpet, in some cases.
  
  
• basement carpet:  Carpeting in basements below grade level is especially at risk in areas where humidity is high, or where wide temperature swings can produce condensation.
  
  
• odors and stains:  There is a wide range of things that can cause odors and stains on carpets.  If mold is suspected, samples can be taken and sent for analysis to determine if mold growth has occurred.

Preventing Mold Growth in Carpeting
The best method for combating mold is to not allow mold growth in the first place.  The best way to do so is by ensuring that conditions conducive to growth do not exist.  Below are some ways to prevent mold growth in carpets.

• Reduce indoor humidity.  The use of dehumidifiers will help control moisture in the air, depriving mold spores of the water they need to grow into mold.  A range of 30% to 60% humidity is acceptable for interiors.
  
  
• Install intelligently.  Do not install carpeting in areas that are likely to be subject to frequent, high moisture.  Carpet in a bathroom, for example, will quickly turn to a breeding ground for mold growth due to the high humidity from constant water use in that area.
  
  
• Choose high-quality carpet padding.  Solid, rubber-slab carpet padding with anti-microbial properties is available.  It is slightly more expensive than other types of padding but can be helpful for preventing the growth of mold, especially in climates prone to periods of high humidity.
  
  
• Never allow standing water.  Carpet exposed to standing water will quickly be ruined.  If standing water ever occurs because of a leak or a spill, all carpeting exposed must be immediately cleaned and dried.  The top and bottom surfaces of the carpet, any padding, and the floor underneath must be cleaned and completely dried within a short period of time after exposure to standing water if the carpet is to be saved.  If a large flood has occurred, or if standing water has been present for any extended period of time, the carpet will probably need to be replaced.
  
  
• Clean smart.  When carpeting needs to be cleaned, try to use a dry form of cleaning, when possible.  If any water, liquid, or other moisture has come in contact with the carpet during cleaning, be sure it is dried thoroughly afterward.
    

Removing Mold From Carpet
In many cases, if mold has grown on carpet, cleaning will not be possible.  If growth has occurred on more than one area of the carpet, or if there is a large area of growth, the carpet will probably need to be replaced.  
Small areas of growth that have been quickly identified can sometimes be dealt with.  Detergent and water used with a steam-cleaning machine may be enough to clean the carpet thoroughly.  It is then important to ensure that the carpet dries completely after cleaning to prevent the growth from recurring.  Stronger cleaning agents can be substituted if detergent does not work.  Anything stronger than detergent or common rug-cleaning products should first be tested on an inconspicuous area of the carpet to ensure that the rug will not be damaged during cleaning.  About 24 hours is a reasonable amount of time to wait after testing to be sure that wider cleaning will not discolor or damage the carpet. 
Another option in instances where mold growth is not widespread is to remove the ruined section of the carpet.  If cleaning has been attempted unsuccessfully, the area of mold growth may be removed and replaced with a patch of similar carpet.  Of course, this will only work in situations where aesthetics are not a big concern, since exactly matching the patch to the original carpet may be difficult and the seam may be visible.  If mold has grown in more than one area of the carpet, or if the area of growth is larger than a couple of feet, this will probably not be an effective method of mold removal. 
 
As with all areas of the interior at risk for mold growth, prevention is the best method of control for carpet mold.  Eliminating high-moisture conditions and preventing the risk of flooding or standing water will reduce the possibility of growth.  Inspectors will want to know where to look for and how to identify mold growth in carpeting.  It is also helpful to know how to determine if carpet should be replaced, or whether there is a possibility of cleaning and saving it.

Carpet beetles are household pests capable of destroying various household items. Inspection and knowledge of their habits can prevent costly destruction. 
Life Cycle and Habits
Female carpet beetles will lay 50 to 100 small, pearly-white eggs on protected surfaces near a food source, such as the lint around baseboards, in the ductwork of hot-air furnace systems, and on wool clothing in storage. Larvae emerge once the eggs hatch after six to 11 days in warm weather, although they may require more time in cool weather. The larval life spans between 250 to 650 days, most of it spent scavenging for protein-rich food in dimly lit areas. By the time they reach adulthood, carpet beetles will live for only another few weeks or months, and they will no longer damage household goods. Unlike larvae, adults are attracted to light and can be found busily flying around windows or feeding on pollen outdoors.
Types of Carpet Beetles
 
Carpet beetles come in several types of subspecies, including the following: 

• black carpet beetle:  Adults are oval and shiny black, with brownish legs. They vary in length from 1/8-inch to 3/16-inch. Larvae are golden to dark brown, and about 1/2-inch long. The body is narrow and elongated, and narrows toward the rear. 
• varied carpet beetle:  Adults are 1/10-inch to 1/8-inch long and nearly round. The top surface is usually gray, with a mixture of white, brown and yellow scales, and irregular black crossbands. The bottom surface has long, gray-yellow scales. Larvae are about 1/4-inch long, and light to dark brown in color. The body is wide and broader at the rear than the front. 
• furniture carpet beetle:  Adults are 1/16-inch to 1/8-inch long, nearly round and whitish, checkered with black spots, each outlined with yellowish-orange scales. The bottom surface is white and the legs have yellow scales. Larvae are about 1/4-inch long, elongated and oval, and thickly covered with brownish hair. 
• common carpet beetle:  Adults are 1/10-inch to 1/8-inch long, nearly round, and gray to black. They have minute, whitish scales and a band of orange-red scales down the middle of the back and around the eyes. Larvae are similar to those of the varied and furniture carpet beetles. 

Damage and Inspection
Carpet beetle larvae prefer to feed in dark, protected places, consuming and damaging wool, fur, silk, cashmere, feathers, bone, and synthetic and cellulose-based fibers that contain some amount of animal fibers. Check for larvae and their cast skins under baseboards, and in and under upholstered furniture, air ducts, stuffed animals, stored cereals and grain, abandoned bird and wasp nests under eaves, and in attics, and clothes closets. Stored items are vulnerable to severe damage, so periodically inspect woolens and other susceptible items. Also, inspect for improperly sealed windows, as these are a likely entry point for carpet beetles, although the insects are small enough that it may be impossible to completely prevent their entry.
It is important for the homeowner to know the difference between carpet beetle damage and damage caused by other pests, such as clothes moths. Fortunately, the distinction is simple; moth infestations are often accompanied by adult moths flying nearby, and you will likely find adult moths, pupae casings or cocoons and larvae in your clothes. Carpet beetles are less conspicuous, as they typically move elsewhere after feeding, and the adults spend much of their time outdoors.  Telltale signs of beetle-damaged clothing include small, irregular holes, especially around the collar. 
Chemical Treatments 
 
Homeowners interested in pest control measures for eliminating carpet beetles indoors have the following options: 

• permethrin:  This product is relatively safe and is recommended for mild infestations. 
• cyfluthrin:  This poison is longer-lasting than permethrin. 
• pheromone traps:  These baits attract adults using special scents, which lures them into glue from which they cannot escape. This measure will diminish the number of active adults, which, in turn, will reduce the risk of future infestations elsewhere in the building. 
• diatomaceous earth and silica aerogel:  These substances, known as desiccants, cause insects to lose moisture and, in small quantities, they are relatively harmless to humans.

Non-Chemical Treatment

• Sanitation is the best way to avoid carpet beetle infestations. Practice thorough and frequent vacuuming and sweeping of carpets, rugs, draperies, closets, drawers, upholstery, air ducts, corners, baseboards, and other places where lint and hair accumulate. 
• Wash your clothes to remove adults, larvae, eggs or pupae. Be sure to throw away badly infested pieces. 
• Remove dead insects and rodents. Carpet beetles feed on animal waste, including their excreta and carcasses, so be sure to inspect for dead insects, especially around windowsills, and control any rodent population in your home. Avoid poison baits, as dying mice may be found more quickly by the beetles than by you. 
• Thoroughly inspect second-hand items before bringing them into your house and immediately launder them, as carpet beetles often hitchhike into homes on clothing, rugs, quilts, and other items of animal origin.   
• Tightly seal windows and other openings, especially near flowers and shrubbery, where adults are likely to be found.  

In summary, carpet beetles are a common source of damaged household items, and measures should be taken to prevent infestation.

by Nick Gromicko 
​

Carbon monoxide (CO) is a colorless, odorless, poisonous gas that forms from incomplete combustion of fuels, such as natural or liquefied petroleum gas, oil, wood or coal.
 
Facts and Figures

• 480 U.S. residents died between 2001 and 2003 from non-fire-related carbon-monoxide poisoning. 
• Most CO exposures occur during the winter months, especially in December (including 56 deaths, and 2,157 non-fatal exposures), and in January (including 69 deaths and 2,511 non-fatal exposures). The peak time of day for CO exposure is between 6 and 10 p.m. 
• Many experts believe that CO poisoning statistics understate the problem. Because the symptoms of CO poisoning mimic a range of common health ailments, it is likely that a large number of mild to mid-level exposures are never identified, diagnosed, or accounted for in any way in carbon monoxide statistics. 
• Out of all reported non-fire carbon-monoxide incidents, 89% or almost nine out of 10 of them take place in a home.

Physiology of Carbon Monoxide Poisoning
When CO is inhaled, it displaces the oxygen that would ordinarily bind with hemoglobin, a process the effectively suffocates the body. CO can poison slowly over a period of several hours, even in low concentrations. Sensitive organs, such as the brain, heart and lungs, suffer the most from a lack of oxygen. 
High concentrations of carbon monoxide can kill in less than five minutes. At low concentrations, it will require a longer period of time to affect the body. Exceeding the EPA concentration of 9 parts per million (ppm) for more than eight hours may have adverse health affects. The limit of CO exposure for healthy workers, as prescribed by the U.S. Occupational Health and Safety Administration, is 50 ppm.
 
Potential Sources of Carbon Monoxide
Any fuel-burning appliances which are malfunctioning or improperly installed can be a source of CO, such as:

• furnaces; 
• stoves and ovens; 
• water heaters; 
• dryers; 
• room and space heaters; 
• fireplaces and wood stoves; 
• charcoal grills; 
• automobiles; 
• clogged chimneys or flues; 
• space heaters; 
• power tools that run on fuel; 
• gas and charcoal grills; 
• certain types of swimming pool heaters; and  
• boat engines.

 
 
 
 
PPM 
% CO 
in air
Health Effects in Healthy Adults
Source/Comments

0
0%
no effects; this is the normal level in a properly operating heating appliance
 

35
0.0035%
maximum allowable workplace exposure limit for an eight-hour work shift
The National Institute for Occupational Safety and Health (NIOSH)

50
0.005%
maximum allowable workplace exposure limit for an eight-hour work shift
              OSHA

100
0.01%
slight headache, fatigue, shortness of breath, 
errors in judgment


125
0.0125%
 
workplace alarm must sound (OSHA)

200
0.02%
headache, fatigue, 
nausea, dizziness


400
0.04%
severe headache, fatigue, nausea, dizziness, confusion; can be life-threatening after three hours of exposure
evacuate area immediately

800
0.08%
convulsions, loss of consciousness;
death within three hours
evacuate area immediately

12,000
1.2%
nearly instant death


 
 
CO Detector Placement
CO detectors can monitor exposure levels, but do not place them:

• directly above or beside fuel-burning appliances, as appliances may emit a small amount of carbon monoxide upon start-up; 
• within 15 feet of heating and cooking appliances, or in or near very humid areas, such as bathrooms; 
• within 5 feet of kitchen stoves and ovens, or near areas locations where household chemicals and bleach are stored (store such chemicals away from bathrooms and kitchens, whenever possible); 
• in garages, kitchens, furnace rooms, or in any extremely dusty, dirty, humid, or greasy areas; 
• in direct sunlight, or in areas subjected to temperature extremes. These include unconditioned crawlspaces, unfinished attics, un-insulated or poorly insulated ceilings, and porches; 
• in turbulent air near ceiling fans, heat vents, air conditioners, fresh-air returns, or open windows. Blowing air may prevent carbon monoxide from reaching the CO sensors.

Do place CO detectors:

• within 10 feet of each bedroom door and near all sleeping areas, where it can wake sleepers. The Consumer Product Safety Commission (CPSC) and Underwriters Laboratories (UL) recommend that every home have at least one carbon monoxide detector for each floor of the home, and within hearing range of each sleeping area; 
• on every floor of your home, including the basement (source:  International Association of Fire Chiefs/IAFC); 
• near or over any attached garage. Carbon monoxide detectors are affected by excessive humidity and by close proximity to gas stoves (source:  City of New York); 
• near, but not directly above, combustion appliances, such as furnaces, water heaters, and fireplaces, and in the garage (source:  UL); and 
• on the ceiling in the same room as permanently installed fuel-burning appliances, and centrally located on every habitable level, and in every HVAC zone of the building (source:  National Fire Protection Association 720). This rule applies to commercial buildings.

In North America, some national, state and local municipalities require installation of CO detectors in new and existing homes, as well as commercial businesses, among them:  Illinois, Massachusetts, Minnesota, New Jersey, Vermont and New York City, and the Canadian province of Ontario. Installers are encouraged to check with their local municipality to determine what specific requirements have been enacted in their jurisdiction.
How can I prevent CO poisoning?

• Purchase and install carbon monoxide detectors with labels showing that they meet the requirements of the new UL standard 2034 or Comprehensive Safety Analysis 6.19 safety standards. 
• Make sure appliances are installed and operated according to the manufacturer's instructions and local building codes. Have the heating system professionally inspected by an InterNACHI inspector and serviced annually to ensure proper operation. The inspector should also check chimneys and flues for blockages, corrosion, partial and complete disconnections, and loose connections. 
• Never service fuel-burning appliances without the proper knowledge, skill and tools. Always refer to the owner's manual when performing minor adjustments and when servicing fuel-burning equipment. 
• Never operate a portable generator or any other gasoline engine-powered tool either in or near an enclosed space, such as a garage, house or other building. Even with open doors and windows, these spaces can trap CO and allow it to quickly build to lethal levels. 
• Never use portable fuel-burning camping equipment inside a home, garage, vehicle or tent unless it is specifically designed for use in an enclosed space and provides instructions for safe use in an enclosed area. 
• Never burn charcoal inside a home, garage, vehicle or tent. 
• Never leave a car running in an attached garage, even with the garage door open. 
• Never use gas appliances, such as ranges, ovens or clothes dryers to heat your home. 
• Never operate un-vented fuel-burning appliances in any room where people are sleeping. 
• During home renovations, ensure that appliance vents and chimneys are not blocked by tarps or debris. Make sure appliances are in proper working order when renovations are complete. 
• Do not place generators in the garage or close to the home. People lose power in their homes and get so excited about using their gas-powered generator that they don't pay attention to where it is placed. The owner's manual should explain how far the generator should be from the home. 
• Clean the chimney. Open the hatch at the bottom of the chimney to remove the ashes.  Hire a chimney sweep annually. 
• Check vents. Regularly inspect your home's external vents to ensure they are not obscured by debris, dirt or snow.

 
In summary, carbon monoxide is a dangerous poison that can be created by various household appliances. CO detectors must be placed strategically throughout the home or business in order to alert occupants of high levels of the gas.