Clean Air Spaces: Indoor Air Filtration to Protect Public Health During Wildland Fire Smoke Episodes - What are the Knowns and Unknowns? June 13-14, 2019

Making a Safe Indoor Space During High Pollution Outdoor Events

Terry Brennan Camroden Associates, Inc.

Web Summit hosted by U.S. EPA Office of Research and Development, Air and Energy National Research Program Get a particle monitor

So you can tell whether your efforts to lower indoor particle levels are making things better or worse. Best way to reduce indoor PM2.5? Build a TIGHT on so outdoor particles stay out!

Modeling indoor PM2.5 concentrations

Old leaky – 20ACH50

Typical older homes – 10ACH50

New EnergyStar homes – 3ACH50

Azimi et al. (2016) Science Technol Built Environ Portable air cleaner in every

• Run portable air cleaners in every room. • Run fan powered outdoor air ventilation systems with MERV 13 or greater filtration. • Turn off and seal all other ventilation systems. • Run central air AC/ normally if the unit and ducts are inside the house. Keep interior open to avoid air distribution induced I/O pressure differences. • Central AC/furnace in a vented crawlspace or are likely to increase entry of outdoor air through leaks on the return side. Keep them turned off as much as possible. Portable air cleaner in every room

• Closing the interior doors prevents free air flow from supplies in the to the central return in the corridor. • When the AC/furnace runs the bedrooms run positive relative to outdoor air and the living area runs negative. This increases the amount of outdoor air flowing through the . • How important this is depends on how bad the outdoor air and how leaky the building shell. Portable Air Cleaner in a Safe Room

• Use portable filters in one or two . • A master with bath is a good candidate. Keep doors between the safe rooms and the rest of the house closed. • Seal AC/furnace air supplies and grilles • Run portable air cleaner sized for the area of the safe rooms. • Run central air AC/furnace if the unit and ducts are inside the house. Keep interior doors open. Running central return AC/furnace with interior doors closed and a safe room with portable air cleaner The Technical Details 2018 EPA Guide to Air Cleaners in the Search on “EPA air cleaners” Select “Air Cleaners and Air Filters in the Home | US EPA”

Consumer Guide Technical Summary 7 Pages 74 Pages Portable air cleaners: EPA recommends high CADR

CADR: Clean Air Delivery Rate—The AHAM certification

0.09–1.0 µm Noise can affect the use of portable air cleaners

Portable air cleaners are often loudest at their most effective setting (e.g., their highest flow setting) Peck et al. 2016 Building and Environ

Portable air cleaners are often Air cleaner #1: Max speed used less frequently over time • Some studies have noted/speculated that may be

Air cleaner #2: because of noise Max speed Air cleaner #1: Min speed Sulser et al. 2009 Int All Immunol; Batterman et al. 2012 Indoor Air

Air cleaner #2: Min speed

10 Pressurize a safe room with filtered outdoor air

Outdoor air ventilation can be: • a simple box fan with>MERV 13 filter attached (See ROCIS) • An inline outdoor air fan (e.g. Broan, Panasonic) plus inline filter box • A dehumidifier with outdoor return and outdoor air intakes (e.g. ultra aire) • An ERV or HRV with high MERV filter box. Pressurizing New Airtight with Filtered Air