Issue link: https://hi.iaq.net/i/248503
www.epa.gov/iaq/moisture • If the permanent HVAC equipment cannot be used, plan for temporary heating, cooling and dehumidification. NOTE: Non-vented combustion devices add a great deal of water vapor as well as heat to a space and cannot be used to dehumidify. Guidance 1: Provide or direct contractors, subcontractors or manufacturers to provide operation and maintenance information required to maintain moisture control elements of the HVAC system components. The builder's responsibilities should be spelled out in the contracts and may include: HVAC System Installation Goal 2: Install HVAC systems to effectively implement moisture control systems in the design drawings and specifications. Implement quality assurance programs for the hygrothermal control systems. Provide required incidental labor, materials and equipment to support third-party testing. • Requirements for filters, coils, condensate drainage systems, ductwork, piping, insulation and vapor barriers, pumps, valves, fans, belts, lubrication and controls. Guidance 1: Plan required inspections—who, when, results and remedies—so they can be completed before HVAC components, particularly the distribution systems, are closed in. Verification of HVAC System Installation • Frequency of inspection. • Methods of repairing problems. • Write a plan for moisture control in regard to HVAC equipment and dedicated drying equipment during construction. Use photographs, log books and written reports to document moisture-control activities, water problems and responses to water problems. Guidance 2: Install HVAC systems, condensation collection and drainage systems, system insulation, air barriers and water vapor controls in accordance with construction documents. • Drain pans, drain pan outlets, traps and disposal. • Parties identified in the construction documents or contracts should perform tests as required by the design or for internal quality assurance. These tests include: • HVAC ductwork including seams and sealing prior to the installation of duct insulation. yy Creating air pressure difference maps for each mode of operation. • Insulation and vapor retarders on exposed surfaces that are expected to be below the dew point of ambient air (e.g., chilled water lines, refrigerant lines, air conditioning air handlers and chillers), especially at transitions (e.g., penetrations through walls, floors and ceilings; support clamps; valves; dampers; pumps; blowers; and gauges). yy Testing for air duct tightness target—before installation of ductwork insulation. • Access panels to allow inspection and maintenance of HVAC components (e.g., air handlers, filters, coils, drain pans and the supply duct near the air handler). yy Performing other tests and inspections required by the commissioning plan. Inspect the installation of: yy Testing drainage of condensate drain pans in air conditioners. yy Testing, adjusting and balancing the HVAC system as designed. • The tests and inspections should be documented with field log books, moisture content and vapor emission tests, and photographs. • Exhaust ventilation systems for duct sealing, insulation and vapor control. • Develop written operations and maintenance information, as required by contract. HVAC System Installation Goal 3: Prepare operation and maintenance materials for continued performance of HVAC system moisture control. 85