Issue link: https://hi.iaq.net/i/655416
42 Energy Savings Plus Health | INDOOR AIR QUALITY GUIDELINES FOR MULTIFAMILY BUILDING UPGRADES PRIORITY ISSUE 14.0 ENVIRONMENTAL TOBACCO SMOKE (ETS) (continued) ASSESSMENT PROTOCOLS (AP) MINIMUM ACTIONS (MA) EXPANDED ACTIONS (EA) • Inspect and identify all joints, seams and leaks in the ventilation duct system than can be sealed. Consider following ASHRAE Standard 189.1-2014, which specifies a 25-foot minimum separation distance for exterior smoking areas. • Propose identifying dwelling units where smoking is not allowed, and physically locate these units as far as possible from units where smoking is allowed. Wind- or temperature-induced stack effect and window operation can have a large impact on air transfer between units on different floors. If possible, locate the smoking units higher in the building where there often is more air exfiltration to the outdoors, which also will make the other compartmentalization strategies more effective (see Priority Issue 16.0). 2. Ventilation and Air-Pressure Control • Follow the Minimum Actions in Priority Issues 18.0 through 21.0, as applicable to the type of ventilation system. • For dwelling units served by a central exhaust ventilation system, balance airflows for each unit by sealing duct/shaft leaks and installing air balancing devices (such as constant airflow regulators or orifice plates) at the exhaust points in each dwelling unit. When flows are the same from adjacent dwelling units with similar leakage characteristics, there is less potential for air and odor transfer between units. • If possible, increase outdoor air supply ventilation rates to non-smoking dwelling units to pressurize the units and reduce infiltration. 3. Air Sealing Air sealing may be performed in smoking units, non-smoking units or both. Some air leakage pathways are very difficult to access in existing buildings. It often takes successive rounds of air sealing to reduce migration of ETS, and it is very difficult to eliminate all leakage between dwelling units. • Identify potential areas of uncontrolled ETS leakage from adjacent units via visual inspection, infrared thermography, chemical smoke and/or pressure testing. ASTM E1186-03 (2009) Standard Practices for Air Leakage Site Detection in Building Envelopes and Air Barrier Systems can be used to guide the air sealing assessment work. • Reduce ETS transfer between adjacent units by sealing vertical shafts, joints and penetrations in adjoining walls, ceilings and floors. o Find and seal the largest openings first, for example: joints around plumbing penetrations, joints around ventilation openings, lighting penetrations, openings behind baseboard heaters, electrical outlets, etc. o To track progress during sealing, a blower door depressurization test of airflow at a pressure difference of 50 Pascals can be used. Note that exhaust duct systems should be temporarily sealed off during the blower door depressurization test. • Apply weather-stripping to all doors between dwelling units and common hallways to minimize air leakage into the hallways. If the existing ventilation system relies on make-up air provided to dwelling units by pressurized corridors, do not weather-strip unit entry doors and restore or repair the make-up air system as needed. • If make-up air is not provided by pressurized corridor systems, provide outdoor make-up air to each unit (e.g., trickle vents) and do not install pressurized corridor make-up air systems.