Risk Bulletin. Mold Prevention and Control for Mechanical and HVAC Contractors. XL Group Insurance

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1 XL Group Insurance Risk Bulletin Mold Prevention and Control for Mechanical and HVAC Contractors Mechanical contractors have an inherent risk of mold claims arising out of the heating, ventilation, and air-conditioning (HVAC) and plumbing services they conduct. An effective mold prevention and control program can reduce such risks incurred while installing or servicing systems by proactively addressing moisture control and quality assurance issues. Controlling moisture and implementing quality assurance takes place during the design, construction, and commissioning phases of the project. In addition, investigating and correcting water intrusion and/or mold issues immediately are also key to managing this exposure. The following are considerations for a mechanical/hvac contractor to include in a mold prevention and control plan.

2 Mold Prevention and Control for Mechanical and HVAC Contractors Risk Bulletin 2 Design And Preconstruction Phase One of the primary issues for mechanical/hvac contractors is to ensure that the HVAC system is designed properly for the building and communicate concerns to the client and/or client s design team. If the HVAC system is oversized, the system will not run long enough to dehumidify the building. However, if the system is undersized, the system may run for long periods and still not be able to handle the moisture load resulting in condensation on interior surfaces. Fresh air intakes need to be carefully designed with multiple goals of diluting microbial contaminants, energy efficiency, and moisture and temperature modulation. There are several impacts on occupant comfort and health, equipment maintenance, and system economics associated with an oversized HVAC system (see Table 1). However, equipment is routinely installed with total capacities that are 50% to 200% greater than needed. According to G. Hourahan in an article entitled, Sizing and Selecting Equipment for Proper Humidity Control, steps for sizing equipment correctly include the following: Establish building design and criteria requirements (e.g., duct location and level of sealing and insulation, ventilation or filtration needs, special occupant comfort/ health needs, appearance issues, building constraints, high humidity environments, etc.). Determine the design loads (building construction issues such as the building envelope, solar orientation, glass type and shading, insulation type/level, duct tightness/ location, etc.). There are several impacts on occupant comfort and health, equipment maintenance, and system economics associated with an oversized HVAC system Table 1 HVAC Oversizing Impacts Comfort Large temperature differences between rooms Degraded humidity control Drafts and noise Occupant discomfort/ dissatisfaction Economic Higher installed costs Increased operating expense Increased installed load on the public utility system Equipment Larger ducts installed Increased electrical circuit sizing Excessive part-load operation (i.e., frequent cycling, shorter equipment life) Nuisance service calls Health Potential to contribute to mold growth Potential to contribute to asthma and other respiratory conditions (Reference: Hourahan, G. Sizing & Selecting Equipment for Proper Humidity Control. ARI Magazine. Spring 2003: 24-34) Verify system capacities (i.e., adhere to all manufacturer s sizing, selection, and application guidelines) and identify consequences if load is increased. Evaluate latent requirements (i.e., consider innovative approaches to controlling moisture). If the owner requests an improperly sized system for their needs, the mechanical/hvac contractor should notify the owner of the potential consequence of doing so, and document their recommendations. Additional design and constructability issues for mechanical/hvac contractors to consider in a mold prevention and control program include the following: Flashings at penetrations for piping and electrical conduits, and any other HVAC equipment. HVAC equipment and complete flashings. Insulation of chilled water pipes. Use of mold-resistant materials (such as fire proofing, caulks, sealants, greenboard, etc.). Bathroom fans vented to the exterior and activated by the bathroom light. Verification of floor drain elevations. Use of bare, galvanized ductwork where possible and avoidance of interior linings, such as fiberglass, since such linings can serve as a habitat for mold growth. HVAC designed with filters that have American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Dust Spot Efficiency Rating of at least 50

3 Mold Prevention and Control for Mechanical and HVAC Contractors Risk Bulletin 3 percent. Incorporating an automated building monitoring system (to measure relative humidity, temperature, and carbon dioxide) into the design to proactively monitor the performance of the building s ventilation system. Mechanical/HVAC contractors should also consider the following project management factors in their mold prevention and program: Pre-qualify potential subcontractors and evaluate their experience and technical qualifications. Inform general contractor/construction manager and subcontractors of mold prevention and control program. Peer review mechanical system designs (including shop drawings and detail drawings). Consider the use of a thirdparty design review. Document any recommended changes given to the Architect/Engineer of Record. Obtain approval from the architect/engineer prior to proceeding. If the recommendation is rejected, restate the recommendation in writing with a copy to the project file. Ensure that designs are performed by qualified and experienced personnel who have been trained in mold and water intrusion issues. Early start-up of mechanical systems: Procedures and policies for the early start-up of mechanical/ HVAC systems should be established to decrease the likelihood of mold growth. Depending on the geographical location of the project and the type of project, an early startup of the mechanical system may be done to provide heating or cooling and/or drying out the building of excess humidity. However, if the system is turned on while construction dust is still generated, precautions should be taken so the interior ductwork does not become coated with construction dust, which is especially problematic if the ductwork is lined with fiberglass. The construction dust provides a food source for potential mold growth. Construction Phase During the construction phase, an inspection procedure should be instituted and documented throughout the project criteria to identify mold and potential water intrusion. Photos of all key installations should be taken. Inspections of major phases of the construction work should be considered as third-party inspectors may become experts for the defense on a mold or water intrusion claim. The inspection procedure should include the following: Inspect materials used and delivered to the site. Confirm that they are free of mold and water damage. Confirm that all plumbing, electrical, and duct penetrations are properly sealed to ensure water cannot enter the structure. During the construction phase, an inspection procedure should be instituted and documented Assure construction materials are properly stored and protected from moisture. Seal door and window openings, pipe chases, elevator shafts, roof openings and penetrations from weather. Insulate all chilled water pipes. Remove standing water from the building(s). Protect ongoing and completed flashings, waterproofing, roofing and vapor barriers during construction. Repair damaged materials promptly. Keep drains open and unobstructed. Repair plumbing leaks immediately. Remove trash and debris from the building on a regular basis. Remove wet and/or moldy materials from the site immediately. Install sump pumps and place them in operation as early as possible to prevent flooding. Place equipment that requires water (such as tile saws, mixers, etc.) in tubs during indoor operation to control the spread and seepage of water. Test plumbing and HVAC systems in accordance with local and national codes to ensure there are no leaks. Maintain the signed test records with project documentation. Use various methods of testing of piping (such as air tests) prior to water tests. Charge domestic water lines to the building structure for as long as possible prior to the installation of drywall to help identify potential hidden leaks. Confirm proper backfilling of trenches within and around the buildings to prevent water from entering. Inspect shower receptor installations for proper sealant. Check bathtubs for leaks with special attention to overflows.

4 Mold Prevention and Control for Mechanical and HVAC Contractors Risk Bulletin 4 Confirm proper installation of protection plates on framing members per code to protect plumbing lines. Seal ductwork at separations if demolishing existing systems and remove from building. Confirm that procedures are followed to ensure that construction dust being created does not cause the interior ductwork to be coated with dust in the event of early start-up of HVAC systems. Prior to turning over mechanical/hvac systems to the client, the following are prudent steps to consider: Conduct a documented walkthrough inspection with the general contractor or owner (as appropriate) to identify and correct nonconformances. The walkthrough inspection should cover all critical areas. Measure the humidity levels of the building. Check condensate pans to ensure they are clean. The condensate drain should be checked to ensure it is working properly. Maintain the documentation of the walkthrough inspection in the project files. Upon final acceptance of the mechanical systems, an operations and maintenance manual should be provided to the client that includes both general and equipment-specific manufacturers operations and maintenance procedures. You should also provide mold prevention tips for owners including: Respond to water intrusions immediately. Fix water or sewer leaks immediately. Use air conditioning in hot/humid weather. Keep HVAC system drip pans clean and unobstructed. Maintain humidity levels between 30% and 50%. Communicate mold prevention tips to building occupants. The owner should be informed that extended shutdowns of the HVAC units during nights, weekends, or other periods where the building is unoccupied may appear to be cost-effective, but in reality may create fluctuations in the moisture content throughout the building and create an environment conducive to mold growth. The prevention of water intrusion, moisture and mold for mechanical/ HVAC contractors extends throughout the project lifecycle. Education And Training Education and training are important elements in a contractor s mold control and response program. Essentially, personnel should be trained in accordance with the contractor s specific procedures for controlling mold and water intrusion issues and how to respond to such issues. Additionally, personnel should receive mold awareness training that includes the causes of indoor mold growth, toxicological impact on human health (real or perceived), and risks associated with mold growth to third parties. Customers should also be provided with information and guidance on maintenance procedures and mold prevention tips as previously discussed. Response Procedures Upon notification of water intrusion and/or mold growth, the site should be inspected immediately since mold may grow on water damaged materials within hours. Notification should subsequently be provided to the insurance carrier and other parties affected by the water intrusion. The following basic parameters should be determined during the preliminary investigation: How long has the water intrusion occurred? What is the source of the water/moisture intrusion? Is the source from sewage? Has visible mold growth occurred? What is the size of the water damage or mold growth? How can the source of water intrusion be corrected?

5 Mold Prevention and Control for Mechanical and HVAC Contractors Risk Bulletin 5 A qualified professional, experienced in indoor air quality and mold assessments, should be consulted if necessary. The following is a checklist for investigating and evaluating moisture and mold problems: Assess the size of the water damage or mold area (in square feet). Consider the possibility of hidden mold. Clean up small mold problems and fix the source of moisture before they become large problems. Select a remediation manager for medium or large mold remediation projects. Investigate areas associated with occupant complaints. Identify and correct the source(s) of water/moisture intrusion. Note the type of water-damaged materials. Check inside the air ducts and air-handling unit. The source of water/moisture intrusion and damaged porous materials should be removed and replaced as soon as possible to minimize the extent of the damage. The New York City Department of Health (NYCDH) and the United States Environmental Protection Agency (USEPA) have established remediation guidelines for performing mold remediation in schools and commercial buildings. Remediation should be performed by qualified and trained personnel. The prevention of water intrusion, moisture and mold for mechanical/hvac contractors extends throughout the project lifecycle. Prevention procedures start at the pre-construction phase and are implemented during construction and project completion. Effective management of these issues through a water intrusion management program can decrease the frequency and severity of water/moisture/mold exposures. References Arthur J. Gallagher Construction Services. Mold Action Plan: A Map to Avoiding Mold Litigation. server.pt?open=18&objid=409285&parentname=dir&parentid =1&mode=2&in_hi_userid=26148&cached=true Hourahan, G. Sizing & Selecting Equipment for Proper Humidity Control. ARI Magazine. Spring 2003: Mahoney, D. and Spear, J. Mold Risk Assessment & Remediation. Professional Safety. Aug. 2003: Sheet Metal and Air Conditioning Contractors National Association, Inc. Duct Cleanliness for New Construction Guidelines. Virginia: SMACNA, The information contained herein is intended for informational purposes only and does not constitute legal advice. For legal advice, seek the services of a competent attorney. Any descriptions of insurance provisions are general overviews only. XL Group is the global brand used by XL Group plc s insurance subsidiaries. In the US, the insurance companies of XL Group plc are: Greenwich Insurance Company, Indian Harbor Insurance Company, XL Insurance America, Inc., XL Insurance Company of New York, Inc., and XL Specialty Insurance Company. Not all of the insurers do business in all jurisdictions nor is coverage available in all jurisdictions. Information accurate as of Januray Risk Bulletin Risk engineering information provided by XL Group s Environmental team. 505 Eagleview Boulevard, Suite 100, Exton PA xlenvironmental.com 3116_01/2014