Tuesday, March 30, 2010
Why clean your air ducts?
Benefits that HVAC system cleaning may provide:
Increased Efficiency=Lower Energy Costs.
(For example, a clogged evaporator coil causes air conditioners to run 20% less efficiently on average versus a clean evaporator coil according to ASHRAE www.ashrae.org. Did this dirt just magically appear, or did the furnace apparently pull this dirt through the filter and over time an inevitable build up occurred? More than likely furnace filters are rated to catch a percentage of contamination to a particular micron size and the remaining percentage of contamination is blown to the inside of the evaporator coil by the furnace blower. This would make it conclusive that dirt does in fact move around in a forced air ventilation system. If dirt did not move around in a ventilation system, then there would be no need to maintain a furnace filter. Most, if not all professionally licensed HVAC companies and or contractors will always recommend that you maintain a furnace filter, which is in place to capture circulating dirt, dust or debris). It also has conclusively been proven true that potential harmful molds and bacteria can grow on an evaporator coil see the Center for Disease Control’s informative pdf at http://www.cdc.gov/niosh/pdfs/appenb.pdf.
Obstructions removed in a ventilation system in all instances if the debris is present, will result in increased airflow. (For example when an HVAC professional sizes your air duct system certain rounds are rated to produce a certain amount of CFM of airflow. These CFM measurements can change based on allot of different factors such as trunk line dimensions, supply pipe length distances, the number of elbows present and the diameter of the supply pipe. Hypothetically lets just say a 6” diameter supply round was built to achieve a rating of 118 CFM of airflow and hypothetically lets just say a 3” diameter beer can was present in the round left over from construction. Do you think that a 3” diameter of remaining diameter would allow 118 CFM of airflow still? We didn’t think so either. That beer can in fact, reduces the amount of CFM the supply pipe is able to blow out and it is a good idea to remove obstructions out of the ventilation system so that your supply vents blow the way they were designed to.
Save money on costly equipment repair. (For example, filthy blower motors operate at higher amp draws causing the blower motor to consume more energy and to operate harder than the motor would have operated if the motor was maintained clean. It would be logical to understand that if a blower motor operates at a higher amp draw versus a lower amp draw that the motor would naturally operate hotter and hence would burn out sooner as a result. Very often it is cheaper for the homeowner to pay for a whole house air duct cleaning than it is to pay for a new blower motor. Getting a longer life expectancy out of an expensive blower motor is a good idea. Did the blower motor come equipped with a built in dirt manufacturing plant? We didn’t think so either. More than likely the dirt traveled through the ventilation system and over time a build up occurred to make the blower motor dirty.
You may experience less dust accumulation throughout your home as a result to having this service performed. (For example, different micron (sized matter) has varying weights due to the composition of the matter and its respective micron size. Some matter will not move in the air stream because it is too heavy to move and the CFM of the airflow will not effect that matter, whereas finer micron matter that infiltrated through the furnace filter (remember furnace filters capture a percentage of airborne contamination which is not 100% and to a rated micron size) will continue to blow out of the ductwork and be drawn back in by the return air vents, which are air intakes. Overtime a buildup occurs and when the build up becomes a significant amount, the ventilation system which of coarse is a circulatory system will begin to discharge fine micron matter to a higher level versus if 99 % of this matter was source removed by an occasional air duct cleaning. Would you never clean your bedspread sheets because you were aware of the fact that the bedspread sheets could get dirty again over time? Certainly not, that is disgusting and is not very good hygiene to maintain. So occasionally cleaning out the ventilation system would be a good idea, but if done properly would certainly not need to be performed every year if it was performed by a superior power vacuum air sweep method which will effectively remove 99% of ventilation contamination build up and sometimes greater amount depending on the composition of the matter and if it was heated on overtime or removed right after construction.
Breathe healthier air! A term called sick building illness is an actual medical fact. It is not often that this situation occurs, but has been recorded to occur at various places and times. The most well known incident happened back in 1976 when an American Legion meeting occurred in a building in Philadelphia. This incident in fact created the term Legionella derived from Legion in American Legion. Legionella which is a bacteria, created by moisture, trace nutrients (dirt) and the correct temperature had grown in an air conditioning system and resulted in the worst Legionnaire outbreak in world history. This bacteria, was delivered by forced air through the ventilation system and by early August (1976) news organizations across the country were reporting that 6-14 of the men in Pennsylvania had died. Did the legionella grow wings and aim at a specific target on its own accord? We didn’t think so either. The legionella was delivered by forced air created by an air handler blower and was delivered through the air ducts. This unfortunate incident could have been avoided if the HVAC system was occasionally cleaned out. Every Federal building occasionally has an HVAC system cleaned out throughout America. Is there something that the Federal government is aware of that the average citizen is not aware of?
Duct Cleaning Recommendations found on http://www.cdc.gov/niosh/pdfs/appenb.pdf The CDC does recognize that microbial growth can occur in evaporator coils and condensate drain pans. There always is a potential for these microbial contaminants to be delivered through the ventilation system considering the fact that an air handler blower moves air.
1. Any duct cleaning should be scheduled during periods when the building is unoccupied to prevent exposure to chemicals and loosened particles. (they did not state that this always occurs, they are speculating that there is always a potential for it to occur) The air handling unit should not be used during the cleaning or as an air movement device for the cleaning process. The National Air Duct Cleaning Association recommends that the system should be run to allow at least eight air changes in the occupied space when duct cleaning has been completed.
2. Negative air pressure that will draw pollutants to a vacuum collection system should be maintained at all times in the duct cleaning area to prevent migration of dust dirt, and contaminants into occupied areas. Where possible, use vacuum equipment or fans during cleaning and sanitizing to make sure that cleaning vapors are exhausted to the outside and do not enter the occupied space.
3. If it is determined that the ductwork should be cleaned, careful attention must be given to protecting the ductwork. When gaining access to sheet metal ducts for cleaning purposes, it is essential to seal the access hole properly in order to maintain the integrity of the HVAC system. Access doors are recommended if the system is to be cleaned periodically, and all access holes should be identified on the building’s mechanical plans. Particular attention is warranted when cutting fibrous glass ducts, and manufacturers’ recommended procedures for sealing should be followed stringently. Use existing duct system openings where possible because it is difficult to repair the damage caused by cutting new access entries into the ductwork. Large, high volume vacuum equipment should only be used with extreme care because high negative pressure together with limited airflow can collapse ducts.
4. Duct cleaning performed with high velocity airflow (i.e., greater than 6,000 cfm) should include gentle, well-controlled brushing of duct surfaces or other methods to dislodge dust and other particles. Duct cleaning that relies only on a high velocity airflow through the ducts is not likely to achieve satisfactory results because the flow rate at the duct surface remains too low to remove many particles.
5. Only HEPA filtered (highefficiency particle arrestor) vacuuming equipment should be used if the vacuum collection unit is inside the occupied space. Conventional vacuuming equipment may discharge extremely fine particulate matter back into the atmosphere, rather than collecting it. Duct cleaning equipment that draws the dust and dirt into a collection unit outside the building is also available. People should not be allowed to remain in the immediate vicinity of these collection units.
6. If biocides are to be used, then select only products registered by EPA for such use, use the products according to the manufacturer’s directions, and pay careful attention to the method of application. At present, EPA accepts claims and therefore registers antimicrobials for use only as sanitizers, not disinfectants or sterilizers in HVAC systems. (See Appendix F for definitions of antimicrobials.) There is some question about whether there are any application techniques that will deposit a sufficient amount of the biocide to kill bacteria, germs, or other biologicals that may be present. Materials such as deodorizers that temporarily eliminate odors caused by microorganisms provide only a fresh smell, and are not intended to provide real control of microbiological contaminants.
7. Use of sealants to cover interior ductwork surfaces is not recommended. No application techniques have been demonstrated to provide a complete or long-term barrier to microbiological growth, nor have such materials been evaluated for their potential health effects on occupants. In addition, using sealants alters the surface burning characteristics of the duct material and may void the fire safety rating of the ductwork.
8. Careful cleaning and sanitizing of any parts of coils and drip pans can reduce microbiological pollutants. Prior to using a sanitizer, deodorizer, or any cleansing agents, carefully read the directions on the product label. Once cleaned, these components should be thoroughly rinsed and dried to prevent exposure of building occupants to the cleaning chemicals.
9. Water-damaged or contaminated porous materials in the ductwork or other air handling system components should be removed and replaced. Even when such materials are thoroughly dried, there is no way to guarantee that all microbial growth has been eliminated.
10. After the duct system has been cleaned and restored to use, a preventive maintenance program will prevent the recurrence of problems. Such a program should include particular attention to the use and maintenance of adequate filters, control of moisture in the HVAC system, and periodic inspection and cleaning of HVAC system components. (See discussion of Preventive Maintenance on page 36 in Section 5.)
Lucky Duct has the ability to perform an air duct cleaning to meet or exceed the stated recommendations found on the www.cdc.gov/niosh/pdfs/appenb.pdf address. Lucky Duct in fact follows the ACCA “Restoring of HVAC system” guidelines, which has been formally accredited and recognized as the only national standard by the American National Standards Institute (ANSI).