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Lantz_HVAC System Cleaning 101

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IAQA 18th Annual Meeting & Indoor Environment and Energy Expo (IE3) The views and opinions herein are those of the volunteer authors and may not reflect the views and opinions of IAQA. The information is offered in good faith and believed to be reliable but it is provided without warranty, expressed or implied, as to the merchantability, fitness for a particular purpose or any other matter. system that are large enough to accommodate mechanical cleaning procedures and allow for cleanliness verification. The air ductsshall be cleaned using mechanical agitation methods to remove particulate, debris, and surface contamination and dislodged substances shall be captured with a vacuum collection device. The standard also states that cleaning activities shall not damage any HVAC components. When coil cleaning is performed, both upstream and downstream sides of each coil section shall be accessed for cleaning. When both sides of a coil are not accessible for cleaning then removal and/or replacement may be required. ACR specifies that a visual inspection of the coil and drain pan shall be conducted prior to cleaning a coil.The data gathered from the preliminary inspection will determine whether Type 1 or Type 2 cleaning is required. ACR provides detailed information on how to properly perform Type 1 and Type 2 coil cleaning, along with measuring the effectiveness of coil cleaning via static pressure drop measurement. It is important to note that when preliminary visual inspection reveals suspect microbial matter on any portion of the coil or drain pan, Type 2 cleaning methods shall be performed. Also, when the metal fins of the coil are damaged, deteriorating or showing signs of corrosion, replacement may be necessary. Regarding restoration and repair of mechanical systems, ACR states that restoration procedures shall only be performed after mechanical cleaning. It is recommended that HVAC components be replaced if cleanliness levels specified in ACR cannot be achieved through mechanical cleaning and restoration methods.Additionally, surface treatments may be used to restore the integrity of material surfaces as an alternative to replacement, butshall only be applied after confirming the system has been cleaned and has passed the specified level of cleanliness verification. ACR recommends that porous materials with mold growth (Condition 3) be properly removed and replaced.This task shall be followed by surface cleaning using mechanical cleaning methods. Another very important guideline that HVAC cleaning contractors must follow relates to the application of antimicrobial agents. Antimicrobial agents shall only be applied if active fungal growth is reasonably suspected, or where unacceptable levels of fungal contamination have been verified through testing. Application of these agents shall only be performed after the removal of surface deposits and debris and absolutely must be done in strict accordance with the manufacturer's written recommendations and the EPA registration listing for that product. A recent article in ENR Southwest, "Las Vegas Air Traffic Control Tower Delayed" is an example of just how costly it can be when coatings are misapplied. The new 352-ft.-tall federal air traffic control tower at McCarran International Airport in Las Vegas faces at least a one-year delay for repairs after an antimicrobial coating flaked from ductwork and became airborne. A spray chemical was applied to dry building walls, ducts and subfloors, curbing a potentially toxic black mold called stachybotrys chartarum, which previously shutdown local buildings in the 1990s and 2000s. When the coating was placed in already lubricated flexible ducts, proper adhesion was not achieved; flakes of the substance subsequently became airborne and circulated inside rooms, reports the Professional Aviation Safety Specialists (PASS) organization. This is just one example that reiterates the importance of understanding and following industry guidelines, standards and proper cleaning & restoration protocols. Summary HVAC system cleaning can yield positive results in increased energy savings and efficiencies, along with extended life expectancy of HVAC systems and components. However, in order to achieve these benefits and

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