Indoor air quality is generally worse than most people believe, but there are things you can do about it.
Some Quick Facts:
- Indoor air quality can be worse than that of outdoor air.
- Problems can arise from moisture, insects, pets, appliances, radon, materials used in household products and furnishings, smoke, and other sources.
- Effects range from minor annoyances to major health risks.
- Remedies include ventilation, cleaning, moisture control, inspections, and following manufacturers’ directions when using appliances and products.
Many homes are built or remodeled more tightly, without regard to the factors that assure fresh and healthy indoor air circulation. Many homes today also contain furnishings, appliances and products that can affect indoor air quality.
Signs of indoor air quality problems include:
- unusual and noticeable odors;
- stale or stuffy air and a noticeable lack of air movement;
- dirty or faulty central heating or air-conditioning equipment;
- damaged flue pipes and chimneys;
- unvented combustion air sources for fossil-fuel appliances;
- excessive humidity;
- the presence of molds and mildew;
- adverse health reactions after remodeling, weatherizing, bringing in new furniture, using household and hobby products; and
- feeling noticeably healthier outside.
Common Sources of Air Quality Problems
Poor indoor air quality can arise from many sources. At least some of the following contaminants can be found in almost any home:
- moisture and biological pollutants, such as molds, mildew, dust mites, animal dander, and cockroaches;
- high humidity levels, inadequate ventilation, and poorly maintained humidifiers and air conditioners;
- combustion products, including carbon monoxide from unvented fossil-fuel space heaters, unvented gas stoves and ovens, and back-drafting from furnaces and water heaters;
- formaldehyde from durable-press draperies and other textiles, particleboard products, such as cabinets and furniture framing, and adhesives used in composite wood furniture and upholstery;
- radon, which is a radioactive gas from the soil and rock beneath and around the home‘s foundation, groundwater wells, and some building materials;
- household products, such as paints, solvents, air fresheners, hobby supplies, dry-cleaned clothing, aerosol sprays, adhesives, and fabric additives used in carpeting and furniture, which can release volatile organic compounds (VOCs);
- asbestos, which is found in most homes more than 20 years old. Sources include deteriorating, damaged and disturbed pipe insulation, fire retardant, acoustical ceiling tiles, and floor tiles;
- lead from lead-based paint dust, which is created when removing paint by sanding, scraping or burning;
- particulates from dust and pollen, fireplaces, wood stoves, kerosene heaters, and unvented gas space heaters; and
- tobacco smoke, which produces particulates, combustion products and formaldehyde.
Tips for Homeowners
• Ask about formaldehyde content before buying furniture, cabinets and draperies.
• Promptly clean and dry water-damaged carpet, or remove it altogether.
• Vacuum regularly, especially if you have pets, and consider using area rugs instead of wall-to-wall carpeting. Rugs are easier to remove and clean, and the floor underneath can also be easily cleaned.
• Eliminate unwanted moisture intrusion by checking for sources (such as holes and cracks in the basement and other areas, and leaks from appliances), and by using a dehumidifier.
• Open windows and use fans to maintain fresh air with natural and mechanical air circulation.
• Always open the flue damper before using the fireplace. This will also prevent carbon-monoxide poisoning.
• If your air conditioner has a water tray, empty and clean it often during the cooling season.
• If you smoke, smoke outdoors and away from any windows and doors.
• Use the range vent above your stove whenever you cook.
• Use the bathroom vent whenever you use the bathroom.
• Don’t leave vehicles or lawn care equipment running in your garage. Make sure the door leading from the home to the garage has a door sweep to help keep out vapors.
Your InterNACHI inspector can recommend more ways to help you maintain healthy indoor air quality for you and your family.
Dryer Vent Maintenance & Safety
House fires caused by dryers are far more common than are generally believed. According to 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.
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 that will become airborne water vapor and leave the dryer and homethrough an exhaust duct, more commonly known as the dryer vent.
A vent that exhausts damp air to the home‘s exterior has a number of requirements:
• It should be connected. The connection is usually behind the dryer but may it be under it. Look carefully to make sure it’s actually connected.
• 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 that is designed to turn 90 degrees in a limited space without restricting the flow of exhaust air. Air flow restrictions are a potential fire hazard.
• One of the reasons that restrictions pose a 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, wool 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, a subsequent mechanical failure can trigger a spark, which can cause the lint trapped in the dryer vent to burst into flames. This condition can cause the whole house to catch fire. Fires generally originate within the dryer but spread by escaping through the ventilation duct, incinerating trapped lint, and following its path into the home’s walls.
Problems & Tips
If your dryer vent terminates in the crawlspace or attic, it can deposit moisture there, which can encourage the growth of mold, wood decay, and other structural problems. The vent may also terminate just under the attic ventilators. This is also a defective installation. Make sure your dryer vent terminates at the exterior and away from any doors and windows so that damp, exhausted air won’t re-enter the home. Also, the end of the dryer vent should have a free-moving damper installed to keep out birds and other pests that like to build nests in this warm environment. If you find a screen, this is a defective installation because a screen can block lint and other debris, causing it to accumulate and leading to a house fire. If it’s safety accessible, make sure your dryer vent is unobstructed and that the damper works properly.
WDO & Pest Control
Wood-destroying organisms and other pests can cause serious problems in the wooden structural components of a house, and an infestation may go unnoticed until the damage is already extensive. Control measures include preventing insect entry by sealing holes and cracks, and hiring a professional to apply chemicals for remedial treatment. The most commons types of destructive insects are termites and ants.
Subterranean termites are the most damaging insects of wood. Their presence is hard to notice, and damage usually is found before the termites are seen. You should take measures to prevent infestations, which may require hiring a pest-control service.
If you see the following signs in your house, you might have termites:
• frass or sawdust-like droppings, which result from the termites’ tunneling activity;
• dirt or mud-like tubes or trails on various parts of the home’s structure, such as wooden support members, plumbing pipes, etc.;
• damaged wood members (such as window sills); and
• swarming winged insects within the home, especially in the spring or fall.
Ants are among the most prevalent pests in households, restaurants, hospitals, offices, warehouses, and virtually all buildings where food and water can be found. While mostly harmless to humans, carpenter ants can cause considerable damage.
The following clues are evidence that your home is host to an ant infestation:
• long trails of ants, perhaps numbering in the hundreds or thousands. Ants assemble in long trails along structural elements, such as wires and pipes, and frequently use them to enter and travel within a structure to their destination;
• a few straggler ants, which are scouts in search of food and nesting sites;
• holes or cracks in walls or the foundation, especially where pipes enter the building, and around windows and doors. These can provide entry points for ants and other insects. The kitchen (where food is stored and prepared) is a particular problem area;
• frass deposits, which result from the ants carving tunnels or galleries in the wood;
• a distinctive rustling sound similar to the crinkling of cellophane. Ants are small but their nests are large enough to produce perceptible noise; and
• nests in mulch and vegetation outdoors next to the foundation. Check under potted plants, patio blocks, stepping stones, in piles of rocks, lumber and firewood.
Snakes, spiders, bees and/or scorpions may be living in your crawlspace, and while they pose little structural danger to the house, they certainly can harm you. Rapid retreat there can be difficult, so if you’re in your crawlspace for any reason (storing items, looking for moisture intrusion or a water leak, etc.), be aware of your escape paths, and carry an extra flashlight in case the one you’re using suddenly stops working.
Your crawlspace is also the most likely area in the house where hantavirus may be found. This is partly due to the fact that rodents that carry the pathogen are attracted to areas that are undisturbed by humans. Also, crawlspaces are generally dark places that lack ultraviolet (UV) radiation, which can rapidly inactivate the virus. Exposure to hantavirus may lead to Hantavirus Cardiopulmonary Syndrome (HCS), characterized by headaches, fever, difficulty breathing and, often, death. There is no known cure, vaccine or treatment that specifically targets HCS. However, if the symptoms are recognized early, patients may benefit from oxygen therapy.
The Importance of a WDO Inspection
Regular inspections of your house are an important part of home maintenance. Inspecting for wood-destroying insects can alert you to possible infestations in the wooden structural components of your home—a serious problem that often goes undetected for a long time. Call your InterNACHI inspector for a WDO Inspection if you suspect that your home may be infested.
Jason Sestito, 24GI00170200
Core 360 Home Inspections