Issue link: https://hi.iaq.net/i/248503
www.epa.gov/iaq/moisture HVAC System Installation Issue construction. Plan the required inspection and testing—who, when, results and remedies—so these activities can be completed before the plumbing, ductwork and other components are closed in. In addition, plan the installation sequence so testing can be done before system components are closed in. Improper installation of HVAC systems can create condensation and moisture-control problems. Examples include: • Inadequate dehumidification and pressurization performance of the HVAC system, which can lead to occupant discomfort and mold growth. Guidance 2: Take steps to ensure that equipment and materials meant to remain dry, stay dry. Prepare a list of equipment and materials that must be kept dry, actions planned to protect them during construction, and responses if they get wet. • Condensation on HVAC equipment components, which can damage components, increase maintenance costs, decrease component and system lifespan and lead to mold growth. • Schedule the delivery of HVAC system components so they can be protected immediately from rainwater and plumbing leaks. Uninsulated, galvanized ductwork can tolerate some wetting, but air handlers, insulated components, electronic components, chillers, compressors and controls all need positive protection from weather and moisture. • Inadequate drainage of collected condensate or other water, which can result in moisture damage to the building and its contents and to mold growth. • Inadequate ventilation of indoor humidity sources (e.g., showers, bathrooms, spas and kitchens), which can lead to mold growth and deterioration. • Schedule the installation of HVAC components for when the building or a portion of the building has been made weather-tight. Goals HVAC System Installation Goal 1: Keep HVAC equipment and materials dry during construction and provide temperature and humidity control as required during the close-in phase of construction. • Inspect insulated ductwork and components for moisture damage and mold growth when they are received and before they are installed. Guidance 3: Control temperature and humidity during the close-in phase of construction. Plan the transition from unconditioned interior space to conditioned interior space in conjunction with the designers and owners: HVAC System Installation Goal 2: Install HVAC systems to effectively implement moisture control as specified in the design drawings and specifications. HVAC System Installation Goal 3: Prepare operation and maintenance materials for continued performance of HVAC system moisture control. • Identify situations and processes that will require humidity control for installation and drying of materials. For example, concrete slabs may need to be dried before finish flooring goes down; belowgrade concrete walls may need to be dry before interior insulation and finishes are installed; and temperature and humidity may need to be controlled before painting or varnishing takes place. Guidance HVAC System Installation Goal 1: Keep HVAC equipment and materials dry during construction and provide temperature and humidity control as required during the close-in phase of construction. • Use the permanent HVAC systems to provide required conditioning, if possible. Follow the guidance in Duct Cleanliness for New Construction Guidelines (SMACNA 2010). Guidance 1: Plan when and how the HVAC equipment will be energized and used during 84