Information on different air duct cleaning methods
Power Vacuum/Air Sweep method:
Average equipment value being used to perform an air duct cleaning: $50,000.00-$150,000.00 worth of machinery and equipment
According to NAIMA this method of cleaning is the most thorough form of cleaning a ventilation or HVAC system to deliver the lowest particulate count exiting an HVAC system. Actual air studies by a reputable international organization, such as NAIMA has conclusively proven that this in fact occurs in a ventilation system, which of coarse should be a no-brainer because if particulate matter was merely stuck to the sidewalls of ductwork and did not in fact circulate, then mechanical engineers would have never invented a furnace filter. How many HVAC service technicians have instructed you to never use a furnace filter? Probably, not too many, right? That is because it has been known for several decades that dirt, dust and debris will always circulate in a forced air ventilation system. Fortunately, most people are not completely unaware of this problem and have realized that occasional HVAC system cleaning can produce very good indoor air quality results when performed thoroughly and correctly.
Now that we logically know that forced air systems which moves air in a ventilation system not only moves the air inside of the ductwork, but the fine micron particulate matter that science had previously proven existed floating around with that same air, we can get on to the various cleaning methods that tries to tackle the build up problem that time will cause in a forced air ventilation system.
A raging debate between various companies world-wide tries to advertise and endorse their methods of cleaning to convince a consumer and potential customer that their method of cleaning is superior. Rather than writing a very obvious slanted article, I realized that simply stating what the advantages and disadvantages of each cleaning method is, would allow the consumer or potential customer to decide for themselves as to which cleaning method would best serve them. Yes, I can admit that every cleaning method has a clear advantage and disadvantage. Although I would love to make every consumer and or potential customer our customer, the reality is that many factors affect where a consumer or potential customer turns to for their indoor air quality needs.
Power Vacuum/Air Sweep method:
Average equipment value being used to perform an air duct cleaning: $50,000.00-$150,000.00 worth of machinery and equipment.
This method of cleaning is the most expensive, thorough and risky form of cleaning out there. The machinery can cost anywhere from $50,000.00- $150,000.00. The cost to operate is higher and if the technicians are not properly trained the risk of dusting out a house or breaking something in the house is greater.
The power vacuum/air sweep method involves a powerful large diameter vacuum hose generally ranging in diameter from 8”-12” that moves anywhere from 3000 CFM – 26,000 CFM (cubic feet per minute) of negative air draw depending on the type of power vacuum machinery being used. Typically speaking, having power vacuum machines that moves anymore that 10,000 CFM is foolish, considering the fact that all ductwork is rated for a set amount of CFM based on the size of the ductwork through external static pressure ratings, velocity and ambience. I do have to admit that the more power a vacuum has, the cooler it is to witness, though.
The power vacuum hose is typically installed into the ductwork via a circle cut out which allows for the power vacuum to put the entire side of the ductwork under a complete and sound vacuum draw. By doing so, every vent attached to the ductwork will have a centrally created vacuum present for proper system containment. From there, various mechanical brushes are sent down the rounds to break and push all debris down to where the power vacuum is sucking. Afterwards compressed air ranging from 150 psi – 250 psi air washes anything left by the brushes, to thoroughly and completely clean the round. Once all of the supply/heat pipes are cleaned a variety of different brushes, air whips and blow back jetters are employed to source remove all of the bulk matter back towards the power vacuum. This method of cleaning is superior for actually ridding the ductwork of all loose contamination because there is typically no cleaning obstacles presented by the ductwork that the self propelled mechanical and air tools can’t over come, as well as the fact that the sheer power of the vacuums not only effectively keeps all the debris contained, but has enough power to pull this debris out of the system.
Most thorough mode of cleaning where a positive effect such as increased HVAC system efficiency is realized, increased airflow from supply rounds is realized, less HVAC equipment parts failure is realized (or increased part lifespan occurs) elimination of foul odors presented by isolated incidents where dead animals are presented, animal liquid & solid excretions occur and odor emitting mold/mildew and bacteria occurs and in some cases dust reductions are noticed depending on the amount of contamination that is present in a ventilation system. After this method of cleaning is performed, assuming that the occupant maintains that furnace filter I previously mentioned to manufacturer recommendations, then cleanings may only need to be performed every 3-4 years or even longer if you invest in a high media filter unit.
This method of cleaning takes longer, the machinery costs more, which means you are charged more than what most contact cleaning companies would charge you. If the company does not adequately train their personnel to perform this cleaning method, then the risk of mishap is greater than a contact cleaning company due to the overwhelming power engaged into the ventilation or HVAC system cleaning project. This cleaning process is a louder process due to using effective and powerful machinery.
Contact Cleaning Method:
Average equipment value being used to perform an air duct cleaning: $500.00-$4,000.00 worth of machinery or equipment.
This method of cleaning is the safest form of cleaning in ensuring a reduced amount of mishaps and or errors at a jobsite occurs. Typically speaking, a company will use a glorified shop vac, various carpet cleaning hose attachments in conjunction with carpet cleaning machinery and or even a glorified shop vac with a spinning brush. Most contact cleaning companies will spend 30 minutes to 2 hours in attempting to reach as much ductwork that a person is physically able to reach. A small minority of contact cleaning companies will even make a good go at it and will spend up to 8 hours at an average residential jobsite. It is even fair to say that if a contact cleaning company spent all day, if the ductwork was completely exposed and if the ductwork was small enough, a contact cleaning company could technically perform a thorough job if the technician was motivated to perform a thorough job.
The contact cleaning method of air duct cleaning is usually more affordable in price for the consumer/customer because the equipment is so cheap. The contact cleaning method of air duct cleaning is a safer form of cleaning in ensuring that less mishap and errors occur during a job or project because not much agitation of dirt, dust and debris is being made. Contact cleaning machinery is usually not as loud as power vacuum machinery.
The contact cleaning method of air duct cleaning is very limited in what dirt, dust and debris is actually pulled out of a ventilation and or HVAC system. 2” diameter vacuum hoses cannot suck up 3” diameter beer cans or soda pop cans. Due to the laws of physics in that a 2” diameter vacuum hose leaves behind all large diameter items, no airflow improvement is ever realized after the service is performed. Clumsy shop vac hoses usually cannot effectively clean through most furnaces burners, hence the ash, dirt, carbon and dust that can be found in these burners typically stay in the burners. This results in no efficiency improvement when cleaning out the burners, because the shop vac hose could not fit inside of the burners to properly clean it as compressed air or nitrogen can. Most ventilation and or HVAC systems have portions of ductwork that is not easily accessible due to portions of the ductwork being drywall finished around. Should this be the case at any given jobsite, a consumer and or customer must realize that a large portion of ductwork will not be cleaned as a result when the contact cleaning method of air duct cleaning is employed. Typically a shop vac hose can only reach up to 15’ before the hose just curls up. Some trunk lines may stretch out to over 100’ in distance, which means 15’ would be cleaned and 85’ would go untouched. In ductwork rounds the shop vac hose can usually only reach up to 2 ½ ‘ before the shop vac hose gets stuck. 90 degree turns will almost always make the shop vac end its descent in cleaning down a pipe because the shop vac hose cannot be turned without physical intervention. A greater risk of disconnecting pipes occurs due to the physical nature of the contact cleaning method. Also if any home security wiring, telephone wires or low voltage wiring is ever present in the ductwork, the physical nature of the contact cleaning method in air duct cleaning will increase the chances in breaking such wires, whereas air washing will not compromise such wires in any shape way or form. Most contact cleaning companies will recommend that you should have your air ducts cleaned out every year or two, because they know they left enough debris in the ductwork to try to get at it again in a year or two.
Well there you have it folks. Both common methods in air duct cleaning really do have advantages and disadvantages. I attempted to write this article as fair and balanced as I could using as many facts based on past experiences that I have experienced in performing over 10,000 residential and over 2000 commercial air duct cleanings using both methods of cleaning. Based on my past experiences the advantages and disadvantages in both methods of air duct cleaning that I wrote about are very much so true in my experiences. There are many different cleaning machines and tools out there, which means’ that the chore in selecting a thorough air duct cleaner, can be daunting. I must say that experienced technicians in performing an air duct cleaning service can go along way, especially when a company is committed in investing in the more expensive forms of machinery and specialized tools as Lucky Duct is. In fact our least experienced technician that would show up to your home or office has 3000 + residential air duct cleanings and 850 commercial air duct cleanings performed. Lucky Duct strives to take better care of our people in pay and benefits than most other companies which is why we have been so fortunate in attracting some of the best tech’s out there. Cool machines and tools help, but experienced people can really make the difference in a project result as well.
Tuesday, March 30, 2010
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).
Tuesday, March 23, 2010
Basic things that the homeowner can check to help air flow:
First and foremost, check your furnace filter to see if it is dirty and if so, remove the dirty filter and install a new furnace filter. Plugged furnace filters restrict air flow by creating a pressure drop. Next, walk around your house to see if any cold air returns have anything such as couches, rugs or cabinets obstructing the vent. If anything is obstructing the vent, then remove these obstructions so that the cold air return, which is an air intake, can draw in enough air. Last, but not least, walk around your home to check to see if all supply registers (heat vents that blows out air) are open. All supply registers should be open. A popular homeowner misconception, is that by shutting off certain vents throughout the house will cause other vents to blow harder. This simply is not true, because CFM (a measurement of air flow, cubic feet per minute) is determined by the pipes diameter and only so much CFM can ever blow out due to the size of the round, regardless if other registers are shut off or not. Shutting down too many supply registers usually causes more harm than good by creating pressurization problems with the overall duct system, that in an extreme case can actually cause your furnace to short cycle on a high limit and hence increases the cost on your utility bill while working key HVAC components and parts to reduce their life expectancy. Never buy and install heat vent filters either, because these filters really cause pressurization problems too. If there is too much dust blowing out of the vents, then the best thing that you may consider is to have the HVAC system cleaned out thoroughly with the power vacuum/air sweep method in air duct cleaning by an ACCA (Air Conditioning Contractors of America) member company. An average price for a 1 furnace home would cost between $400.00-$700.00 to do the job correctly, depending on where you live in the country and depending on the service providers cost to operate.
Some solutions that an HVAC company or contractor may suggest:
Very often in older homes, air ducts are sized incorrectly due to building departments in the past not emphasizing the importance of properly sized air duct construction and the by the fact that the builder wanted to save a buck to construct his own duct work rather than paying a heating and cooling professional to install the duct work properly. In recent years, many building departments throughout the United States really have zeroed in on enforcing proper duct design, so in most newer homes indoor thermal comfort has improved drastically. Some of the things that your licensed HVAC company or contractor may suggest to you to drastically help your older homes air flow is as follows:
Let me tear out all of your ducts and start over! (That would be sweet, however in many instances that is just not practical due to cost, time and a big mess!)
I can band aide your homes HVAC system by replacing your old inefficient furnace with a Rheem 80% AFUE 2 stage variable speed furnace equipped with the GE ECM motor. Visit www.luckyduct.net to learn more about the GE ECM motor. The GE ECM motor operates 30-40% more efficiently than a standard conventional multi-speed motor and sustains constant CFM even if your duct work is undersized and restrictive. What this means is that vents that seem to never blow air with your inefficient old furnace will all of a sudden blow air after the new Rheem furnace equipped with the GE ECM motor is installed.
For some reason your home does not have enough return air openings to even allow enough air to enter the duct system at all! We need to build additional return air openings into your duct work so that we can get additional CFM into the HVAC system so that your AC indoor evaporator coil can stop freezing. Good golly, you're paying more money on cooling not to mention the fact that your AC doesn't even keep your house cold enough! Let's fix that and add some new return air openings so that you can save some money on your utility bill and actually cool down this summer too!
Let's go ahead and rip out the 4" diameter supply runs and install 6" diameter runs so that we can circulate more air into that sun room!
You know, your ducts amazingly enough are sized correctly, but all of the air is escaping into unfinished portions of the house because the construction of the duct work is very loose. Let's go ahead and seal up every trunk line connection, branch line, and all the end caps with mastic duct sealant. By sealing up every duct connection on the entire system we'll see if we can blow those curtains side ways after all! No, just kidding, but the air will come out a touch harder, though as a result in sealing up the duct work better and you will see a significant reduction in your utility bill because the system will only cycle half as often now.
You know, for some reason all of your duct work is sized correctly, but the return leg that is attached to your furnace is severely undersized and is acting like a choke point. Lets rip this leg out and install a bigger one with a greater dimension!
You know, your home builder really got cheap and should have installed 2 separate systems considering that your home is 3600 Sq/ft. Two smaller systems will actually cost you less on the utility bill to operate and will provide greater comfort. Save up some money and lets build that second system in the attic!
You know, the most cost effective thing that I can think of that will improve your indoor comfort tremendously is to simply just zone your current system so that 3 different thermostats will control 3 different temperatures in your home. Aprilaire and Honeywell make great zoning systems and we usually can get this system installed from $3800.00-$6,000.00 depending on how fancy of a system you want to have installed!
You see some of these band aide jobs will cost just a few hundred dollars, while some solutions may cost a few thousand dollars, but in the end after the corrections are made, your utility bill will probably reduce a bunch and you'll finally have true indoor comfort that you didn't have before. Many HVAC companies and or contractors will give you more than one option to consider as well so that no matter what you decide on some sort of indoor air comfort solution will be achieved to at least improve the comfort situation. The best thing that you can do as a homeowner is to select an ACCA member heating and air conditioning company or contractor to ensure that your comfort specialist has all of the latest and greatest training, tools and professional assistance to best serve you as a customer. In the long term you won't regret it because you will save some money on the utility bill and you will be much more comfortable in your home as a result.
Visit www.luckyduct.net to check out your new HVAC contractor in the Denver and surrounding areas. Our telephone number is (303) 246-5475 and our line is open 24hrs a day.