Air sealing the building envelope is one of the most critical features of an energy efficient home. As new homes grow increasingly tighter to achieve ever higher levels of energy efficiency, the potential for indoor air pollution also increases.
During construction, there are hundreds of penetrations through a typical home’s exterior. These gaps and holes are often incurred during framing, and from penetrations for wiring, plumbing, and ducts. Air leakage accounts for 25–40% of the energy used for heating and cooling in a typical home. To make a home energy efficient, these gaps and holes are closed and insulated to prevent the loss of conditioned air.
Indoor Air Quality Concern
Good indoor air quality is achieved by reducing or eliminating sources of indoor air contamination and providing sufficient fresh air through the heating and ventilation system. While older homes were not energy efficient, they typically did not have problems with indoor air quality because they allowed for fresh air to freely circulate within the home.
As new homes grow increasingly tighter to achieve ever higher levels of energy efficiency, potential indoor air pollution also increases since many conventional building materials emit volatile organic compounds like formaldehyde. While energy efficiency is important, gains in energy efficiency, especially in new homes, should not come at the expense of deterioration of indoor air quality and corresponding adverse health impacts.
Source Elimination and Control
The best way to address indoor air pollution is through aggressive source elimination and control. Pollution should be prevented or reduced at the source whenever feasible.
Building materials: If you are having the home constructed or remodeling your home select materials that do not emit volatile organic compounds.
HVAC System: Make sure your HVAC system distributes the minimum level of outdoor air throughout the home using whole-house mechanical ventilation.
Sealing Air Ducts: Sealing ducts can help improve indoor air quality by reducing the risk of pollutants entering ducts and circulating through your home as well as preventing the loss of conditioned air.
Air Duct Cleaning: Ventilation systems distribute the air you breathe. Have the air ducts and HVAC system professionally cleaned to remove construction debris and pollutants.
Monitor use of household cleaning supplies: Some household chemicals can be extremely dangerous. Choose environmentally safe cleaning supplies, and make sure that the area is well ventilated.
Check exhaust systems: Make sure exhaust fans are clean and unobstructed. Exhaust systems are responsible for removing moisture, odors, fumes, and carbon monoxide.
Many Companies within the HVAC Inspection, Maintenance and Restoration Industry have seen a dirty HVAC system, but what about on filled with 5,000 pounds of sand and black powder? Recently Ductworks Inc. of Arvada, Colo., a long-time NADCA member, participated in the Do-It-Yourself cable network program “Disaster House.”
The show damages a house to then show viewers how to prevent the damages, how to clean them up, and then what to know before filing an insurance claim. In the particular episode, a six foot sand-foot tall, 5,000 pound sand castle was blown up to simulate an extreme case of dirty air ducts and Ductworks was called in to clean the mess up. They got the system back up to pristine conditions after a full day of hard work. Although most homes do not see 5000 pounds of dust and debris, it goes to show that even the dirtiest residential air ducts can be cleaned.
Ensuring good indoor air quality is easy once you have an understanding of the components that effect your homes environment. Using the steps below, perform a quick checklist to improve your indoor quality.
Setting the Standard for Indoor Air Quality
ASHRAE, the American Society of Heating, Refrigeration and Air Conditioning Engineers developed Standard 62.2, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings. The standard, which is widely accepted by green builders, state and local around the counties, defines the roles of and minimum requirements for mechanical and natural ventilation systems and the building envelope in order to provide acceptable IAQ in low-rise residential buildings.
10 Steps to Ensure Good Indoor Air Quality
Vent bathrooms, kitchens, toilets and laundry rooms directly outdoors. Use energy efficient and quiet fans.
Avoid locating furnaces, air conditioners and ductwork in garages or other spaces where they can inadvertently draw contaminants into the house.
Properly vent fireplaces, wood stoves, and other hearth products; use tight doors and outdoor air intakes when possible.
Vent cloths dryers and central vacuum cleaners directly outdoors.
Store toxic or volatile compounds such as paints, solvents, cleaners, and pesticides out of the occupiable space.
Minimize or avoid unvented combustion sources such as candles, cigarettes, indoor barbecues, decorative combustion appliances or vent free heaters.
Provide operable windows to accommodate unusual sources or high-polluting events, such as the use of home cleaning products, hobby activities, etc.
Use sealed-combustion, power-vented or condensing water heaters and furnaces. When natural-draft applications must be used, they should be tested for proper venting and should be located outside the occupied space when possible.
Put a good particle filter or air cleaner in your air handling system to keep dirt out of the air and off your ductwork and heating and cooling components.
Distribute a minimum level of outdoor air throughout the home using whole-house mechanical ventilation.
Source: ASHRAE Standard 62.2 Ventilation and Acceptable Indoor Air Quality on Low-Rise Residential Buildings, and 2001 ASHRAE Handbook, Fundamentals, Chapter 26, Ventilation and Infiltration.
Qualified air duct cleaning contractors employ a variety of different power, pneumatic and hand tools when cleaning air ducts. While there are numerous types of equipment used in the air duct cleaning industry, the job site to a large extent, defines what air duct cleaning tools will be used.
Breaking Contaminants Loose
Properly cleaning HVAC systems requires removing the sources of contamination from the walls of the air ducts. Just as there are numerous types and sizes of air ducts, they are numerous air duct cleaning tools used to loosen debris from the walls of the air ducts.
Mechanical Agitation: Mechanical air duct cleaning tools are typically brushes powered through an electric motor, and are generally used for sheet metal air ducts. Mechanical air duct cleaning tools are primarily used for more aggressive cleaning applications.
Pneumatic Agitation: Pneumatic air duct cleaning tools utilize compressed air to agitate debris from the walls of the air ducts. There are numerous pneumatic air duct cleaning tools that can be used such as air whips, compressed air nozzles, or skipper balls. Pneumatic air duct cleaning tools are primarily used to clean sensitive materials such as internally lined fiberglass air ducts, fiberglass duct board, and flex line air ducts.
Hand-brush & Contact Vacuuming: When accessible, hand brushing and contact vacuuming with a HEPA filtered hand vacuum is always the most effective method of cleaning.
Collection of Contaminants
A vacuum is the most commonly used air duct cleaning tool in the air duct cleaning industry. The most important consideration for every ventilation cleaning project is the prevention of cross contamination. During air duct cleaning, the entire HVAC system is placed under negative pressure (vacuum) to collect loosened debris and prevent the spread of contaminants. There are two main types of collection devices:
Truck Mounted Vacuums: Truck Mounted Vacuums are gas powered vacuums that are powered through the PTO of an operating vehicle. The amount of vacuum typically ranges from 10,000 – 15,000 cfm. Because of the high volume of air the Truck Mounted Vacuum draws, they have a high propensity for drawing vehicle exhaust and contaminants within the workspace.
Portable HEPA filtered Vacuums: In most instances, portable HEPA filtered vacuums are the most effective vacuum collection device. HEPA filtered vacuums have a high velocity of vacuum draw allowing for greater lift of the debris and can often be brought to the contaminant source. HEPA filters prevent contaminants from being dispersed from the vacuum exhaust and prevent the potential of cross contamination.
Most commercial air duct systems are internally lined with fiberglass duct liners. Deteriorating fiberglass duct liner is a very common cause for indoor air quality complaints and adverse health effects.
Fiberglass Duct Liner
Fiberglass internal duct liner is commonly used in many commercial heating, ventilation, and air conditioning (HVAC) system. Fiberglass duct liner provides sound attenuation by dampening noise from HVAC equipment, and sound from adjacent office spaces. Fiberglass duct liner provides thermal insulation for air ducts, preventing the air ducts from losing expensive conditioned air.
Fiberglass Duct Liner Deterioration
Over time internal fiberglass duct liner is exposed to varying degrees of air turbulence, temperature and humidity. These environmental changes take its toll on the duct liner, breaking down its primary seal.
The primary seal is a black gritty coating on the surface of the duct liner which locks down the fiberglass fibers. Deteriorated primary coating migrates through the ventilation system depositing within HVAC components and eventually entering the indoor air.
After the primary seal has fully deteriorated, it allows raw fiberglass fibers to be exposed to the airstream. Turbulent airstreams wick the raw fiberglass fibers through the ventilation system, creating additional deposits within HVAC components and exposing building occupants to raw fiberglass fibers.
Health Effects of Fiber Glass Fibers
Health effects from exposure to fiberglass can be different depending on the fiber size and type of exposure. Fiberglass, at a minimum, is an acute physical irritant to the skin, eyes, and upper respiratory tract.
While no long-term health effects should occur from touching fiberglass. Rashes can appear when the fibers become embedded in the outer layer of the skin.
Eyes may become red and irritated after exposure to fiberglass as occupants touch horizontal surfaces with deposits of fiberglass fibers, and rub their eyes.
Soreness in the nose and throat can result when fibers are inhaled. Asthma and bronchitis can be aggravated by exposure to fiberglass.
Temporary stomach irritation may occur if fibers are swallowed.
How Can Fiberglass Air Ducts Be Repaired?
If caught in the early stages of deterioration the internal fiberglass duct liner can be repaired. Fiberglass duct liner can be resurfaced with an encapsulate specifically designed for HVAC systems. Initially a commercial air duct cleaning needs to be performed to remove the foreign debris from the air duct surface to ensure for a proper bond. After the air duct system is cleaned, the encapsulate is applied to the air duct surface locking down the fiberglass fibers.
If the internal fiberglass lining to too deteriorated, the lining must be removed and replaced. If the damage is localized, new internal internal insulation can be installed within the ducting. If the damage is extensive, consider removing the damaged insulation and wrapping the air ducts with an external fiberglass insulation.
Dust is a combination of pollen, plant and mold spores, pet dander, human skin, lint, bacteria, and other contaminants. While any of these can affect breathing and allergies, dust mites can be a particular problem.
What is a Dust Mite?
Dust mites are tiny insects that are invisible to the naked eye that feed on human skin flakes. Dust mites thrive in stable environments like indoor dwellings and can survive in almost any temperature at almost any altitude. In other words, dust mites are in every home that has dust.
Why are Dust Mites Dangerous?
Dust mites can negatively affect human health because they are a common trigger for allergies and asthma. Body parts and feces from dust mites can trigger asthma in individuals with allergic reactions to dust mites, and exposure to dust mites can cause asthma in children who have not previously exhibited asthma symptoms.
How to Control Dust Mites
While you cannot eliminate dust mites, the easiest way to limit the amount of dust mites in your home is to limit the amount of dust in your home.
Wash bedding and pillows in frequently as dust mites thrive in these areas where skin flakes collect. If necessary, mattresses and pillows can be covered in allergen-impermeable covers.
Avoid furry and feathered pets as they contribute to the food sources for dust mites. If you cannot part with your pet, prevent them from occupying your sleeping area.
Vacuum fabric furniture and carpet with vacuum cleaner equipped with a high efficient vacuum filter.
If you have children, choose washable stuffed toys, and keep stuffed toys off the bed.
Dust all surfaces weekly. Do not scatter dust, use a damp cloth when dusting.
Maintain a low relative humidity; the ideal relative humidity in a home is between 30-50%.
Have the air ducts cleaned. Ventilation systems require routine maintenance to prevent dust from being re-circulated throughout the home.
In rare instances, chemicals may be recommended to eradicate dust mites, if this is necessary speak to a professional.
Ductworks, Inc. and National Jewish Health Featured On FOX 31 / KDVR: Martino TV
Consumer advocate Tom Martino featured the Family Air Kit®, an allergen and mold Test Kit, developed by National Jewish Health that tests for substances that can cause allergic and asthmatic reactions.
Tom Martino and Paula Haddock interviewed Jeffery Nathanson, the Executive Director of Business Development and Eddy Frisk, of Ductworks, Inc. to discuss the benefits of the Family Air Kit®
The Family Air Kit® is a cost effective and accurate means of testing the indoor air quality of your home or business. The Family Air Kit® tests the longitudinal effect of dust in the home.
Ductworks, Inc. and National Jewish Health provide a comprehensive approach to controlling symptoms for people who suffer from allergies and asthma.
Pigeon problems have devastating effects on the heating and cooling components and indoor air quality of a commercial facility. Pigeon problems affect employees, maintenance personnel and potentially customers.
HVAC Systems Make Perfect Pigeon Coups
Unfortunately, rooftop heating and cooling units are a perfect place for pigeons to nest. To seek shelter from the elements, pigeons typically enter air handler units through the fresh air intakes and build their nests within the HVAC unit. A single pair of pigeons can generate up to 18 new pigeons per year. Once a nest is established, pigeons are extremely territorial.
Indoor Air Quality
An HVAC system distributes the air throughout a facility. The bacteria, fungi and parasites that live and grow in pigeon droppings can carry and transmit any of 60 known diseases. Exposure to pigeon feces and other organic matter such as feathers carcasses and nesting material from the HVAC system may pose a considerable health threat to people who come in contact with them or inhale the airborne particles from them. Every precaution should be taken to ensure that building occupants and maintenance personnel are protected from pigeon feces.
Damage to HVAC Systems
As pigeons live in the air handler units they peck through filter material allowing unfiltered air and pigeon contaminants to freely enter the ventilation system. There are numerous damaging effects to an HVAC system.
Filter banks: Pigeons peck though filter banks allowing for unfiltered air and pigeon contaminants to be drawn into HVAC components and supply air ducts.
Fan Blower: Pigeon debris builds within the fan blades decreasing airflow.
Air conditioner coils: Pigeon debris compacts within air conditioner coils and clogs the drain pan.
Insulation: Pigeons peck at insulation to create nesting material allowing for raw fiberglass fibers to enter the airstream.
How Do You Correct Pigeon Problems?
Hire a professional wildlife service or animal control contractor to relocate existing pigeons, and install devices to prevent future intrusions. Have the pigeon debris removed by a professional air duct cleaning contractor. Be sure to have the air duct cleaning contractor inspect the supply air ducts downstream of the HVAC unit.
A clothes dryer works by forcing hot air through a turning drum. Wet clothes placed in the drum are then dried by the moving hot air. It is possible for a full load of wet clothes to contain as much as one and a half gallons of water from a typical load of laundry. Lint is created from the clothes as the water is removed and the clothes dry. Overtime as air passes through this exhaust line the lint collects in the screws, bends and elbows and walls of the air duct.
Inspect the Type of Air Duct Attached to the Dryer
Most manufacturers specify the use of a rigid or corrugated semi-rigid metal duct, which provides maximum airflow. Flexible plastic or foil type duct can more easily trap lint and is more susceptible to kinks or crushing, which can greatly reduce the airflow. Replace plastic or foil, accordion-type ducting material with rigid or corrugated semi-rigid metal duct.
Clothes dryer fires account for about 15,600 structure fires, 15 deaths, and 400 injuries annually. Fires can occur when lint builds up in the dryer or in the exhaust duct. Lint can block the flow of air, cause excessive heat build-up, and result in a fire in some dryers.
Air Flow Restriction
New construction trends now situate washers and dryers in nontraditional areas of the house, such as upstairs bedrooms, hallways, bathrooms, kitchens, and closets. These new sites generally require longer dryer vents, and a higher probability for air flow restriction.
Dryer Vent Maintenance and Safety Tips
Proper maintenance for clothes dryers involves removing the lint from the traps, vents, and surrounding areas of the dryer.
Never operate your clothes dryer when you are not home or while you are sleeping.
Clean your lint trap before or after every use.
Install a proper screen to the outside exhaust to prevent animals from entering the dryer vent.
Do not push your dryer too close to the wall as it may cause crimps or bends in the air duct.
Periodically have the dryer vent professionally cleaned.
Evidence has shown that the air within homes and other buildings can be more seriously polluted than the outdoor air. Several factors contribute to poor indoor air quality that can be easily controlled. Follow these simple tips improve your indoor air.
Identify and Remove Pollutant Sources
The relative importance of any single source depends on how much of a given pollutant it emits and how hazardous those emissions are. Educate yourself on the different types of biological, gas, or particulate pollutants that can potentially affect your indoor air quality and takes steps to remove them. To have a greater understanding of potential indoor pollutants read “Understanding Indoor Air Pollutants“.
Improve Air Ventilation
If too little outdoor air enters a home, pollutants can accumulate to levels that can pose health and comfort problems. Most home heating and cooling systems, including forced air heating systems, do not mechanically bring fresh air into the house. When weather permits open windows to increase ventilation. If you are intending to filter the outside air consider improving your heating and cooling system by having it modified to draw filtered outside air
There are many types and sizes of air filters and air cleaners on the market. As air is circulated through a forced air ventilation system debris is trapped within the furnace filter. Use furnace filters with a MERV rating between 7 to 11, and change the filter every 2 months that the filter is in use. If a standalone filtration device is used, use a device that has a high-circulation rate and highly efficient filter.