Issue link: http://iaqnet.uberflip.com/i/637209
n Type of equipment or method used to apply the product including application rate and contact time. n How often the product is applied. Reapply as directed by the label. n In order for the product to be effective it must be used in accordance with the directions for use (application method and rate, and dwell time). n Pesticide manufacturers may make available a diluted-solution or secondary-container-use label (which must be consistent with the EPA-approved label) when using concentrated products. Best Practices n Follow instructions and safety precautions as per the EPA-accepted label. n Use in a well-ventilated area. n Keep in original or properly marked container. n Label all containers. Where concentrated products are used, label containers holding diluted (ready-to- use) products. Sealants Product definition Sealants are materials – liquids of varying viscosity or tapes - used to seal surfaces, joints, connections, gaps and openings. Typical use Sealants are used in HVAC systems to control air leakage. Application method A sealant may be applied like paint with a brush, roller, trowel, or spray equipment. It also may come in a caulk tube and be applied with a caulk gun. Sealants can exist as tape as well. Pros n Improves energy efficiency of an HVAC system. n Improves performance of an HVAC system. n Reduces air leakage, as well as air intake from unconditioned areas. n Some sealants have elastomeric (flexible) properties to maintain integrity of seal. Cons n Difficult to apply after systems have been constructed. n If the material used is not applied properly or does not have the proper characteristics, it may crack, split or separate from the surface it is applied to, allowing air leakage. n During the application or cure, sealants may give off irritating fumes. n Occupants may need to leave the building during application or while the sealant cures. n System may need to remain shut down for a period of time to allow sealant to cure. EPA requirements Most sealants do not make claims of antimicrobial activity, so they do not have to be registered with the EPA. Best practices It is prudent to perform a duct leakage test to determine the condition of the ductwork and establish whether duct sealing would be beneficial. Once the need has been established, the appropriate materials and methods can be chosen. Correct protective equipment should be used by employees applying sealants. Ensure occupants are not exposed to objectionable fume levels during application and drying. Resurfacing Materials Product definition Resurfacing materials (also known as repair coatings) are coatings that are applied to surfaces that show signs of damage or degradation. Typical use Resurfacing materials may be used to coat internally- lined or fiberglass ductwork to provide a smoother surface and control odors in the system. This reduces resistance of airflow in the system. Coatings secure loose fibers to reduce the potential that they will become airborne and enter the conditioned space. Resurfacing materials may also be used to protect duct surfaces from moisture and conditions that may lead to rust and corrosion. Some coatings have antimicrobial ingredients solely to preserve the coating and help retard the growth of mold and fungi on the coating film. In no case should a coating be used in lieu of source- removal cleaning of an HVAC system. Refer to the NADCA Standard, Assessment, Cleaning & Restoration of HVAC Systems. Application method Resurfacing materials are usually applied like paint with a brush, roller or spray equipment. Pros n Can restore integrity to a duct system. n Retards or repairs fiberglass deterioration.