1
Residential Wood Combustion Workshop
U.S. EPA Office of Air Quality Planning and StandardsLarry Brockman
http://www.epa.gov/woodstoves
Significance of Residential Wood Smoke
2
Why do we care about wood smoke?
• Benzene• Toluene• Aldehyde gases• Polycyclic aromatic
hydrocarbons• Dioxin• Particle Matter
or fine particles (PM2.5)
3
Sources of Residential Wood Smoke:
• Wood Stoves
• Fireplaces
• Outdoor Wood Boilers
4
A Large Quantity of Small Sources Distributed Over a Large Geographic Area
• 45 million wood burning appliances in U.S– 35 million fireplaces
– 10 million are wood stoves, either free standing or fireplace inserts• 75% are “conventional” wood stoves built before
EPA’s woodstove regulation in 1990
– 100,000 wood-fired hydronic heaters in use
5
Estimated National Emissions
336,000Woodstoves
1,450-37,000NESCAUM: perhaps 250,000
Outdoor Wood-fired Boilers
84,000Fireplaces
TPY of PM 2.5 (direct)
SOURCES
Source: NEI for All Categories Except OWB
690 %<1Natural Gas Furnaces90 %<1Oil-fired Furnaces10 %Fireplaces70-80 %1Pellet Stoves
67 % or higher7.5 Non-Catalytic4.1 Catalytic
New Wood Stoves(after 1990)
54 %15-30 or moreOld Wood Stoves
30-55 %30-390Outdoor Wood-fired Boilers (OWB)
Efficiency:Percent (%)
Emissions:Grams/hour
PM2.5 Emissions: Emissions and Efficiency Comparisons
7
8
Why we care about residential wood smoke
A small community in Washington state That’s not fog, it’s wood smoke
9
10
11
National Ambient Air Quality Standard: Particle Matter
35 µg/m315 µg/m365 µg/m315 µg/m3PM2.5(Fine Particles)
24-hourAnnual24-hourAnnual
2006 Standards1997 Standards
12
Particulate Matter: What is It?A complex mixture of extremely small particles and liquid droplets
13
• Larger particles (> PM10) deposit in the upper respiratory tract
• Smaller, inhalable particles (≤ PM10) penetrate deep into the lungs
Particulate Matter
Model of interior human lung
14
Who’s affected?
• Everyone, especially children and the elderly• People with existing diseases such as:
– Coronary artery disease– Heart failure– Asthma– Chronic bronchitis and
emphysema
15
National Ambient Air Quality Standard: Particle Matter• Areas whose air quality does not meet the
health-based particle matter standards are called, “nonattainment” areas
• States with non-attainment areas must submit plans, “State Implementation Plans – SIPs”
• Plans must outline how they will meet the particle matter standard
16
Timeline for PM2.5 NAAQS Implementation
39 areas designated for 1997 standardsApril 2005
Attainment date for areas designated in 2005 for 1997 standards
Apr 2010-15
Attainment date for areas designated in 2009-10
April 2014-20PM2.5 State plans due for 2006 standardsApril 2012-13
Final designations for 2006 PM2.5 standards 2008-9PM2.5 State plans due for 1997 standardsApril 2008
States recommend designations for 2006 revised PM2.5 standards
Dec. 2007 2006 revised PM NAAQSDec. 2006
17
EPA estimates by meeting both the 1997 fine particle standards and the 2006 revised 24-hour standard, the fine particle standards will prevent at least:
– 17,500 premature deaths in people with heart or lung disease.
– 77,600 cases of chronic bronchitis– 27,300 cases of acute bronchitis– 97,000 cases of upper and lower respiratory symptoms– hundreds of thousands of occurrences of aggravated
asthma; – 3,450,000 days when people miss work or school
• Based on recently updated estimates, meeting the annual standard will result in benefits ranging from $20 billion to $160 billion a year in 2015.
18
Currently Designated PM2.5 Nonattainment Areas - 1997 StandardsViolated annual and/or 24-hour PM2.5 standards with designated data (2001-2003*)
LegendNonattainment areas violating: Number of Areas
both annual (15 µg/m3) and 24-hour (65 µg/m3) standards 2 ONLY the 24-hour standard (65 µg/m3) 0ONLY the annual standard (15 µg/m3) 37
Total PM2.5 Nonattainment Areas 39
* 2002-2004 data were considered in the designation process but all nonattainment designations were based on 2001-2003 data
19
Areas/Sites Violating 24-Hour PM2.5 NAAQS – 2003-2005
Current nonattainment area violates new 24-hr NAAQS [32 areas]Current nonattainment area meets new 24-hr NAAQS [7 areas]
• Sites not in a current nonattainment area violate the new 24-hr NAAQS (59 sites)
• 59 sites are violating the new 24-hr standard and are NOTlocated in an existing nonattainment area. • They are located in 38 different areas (34 in metro areas, 4 not in a metro area).
20
The benefits of changing out all old wood stoves in the U.S.
Health EffectAvoided Cases
per yearCost Savings
per yearMortality (adult) 5,000 $27,000,000,000Non-fatal heart attacks 7,800 $670,000,000Chronic Bronchitis 3,300 $1,200,000,000Work Loss Days 650,000 $85,000,000Asthma Exacerbation 91,000 $4,000,000Hospital Admissions, Cardiovascular 2,400 $53,000,000Hospital Admissions, Respiratory 2,400 $35,000,000Total NA $29 billion
21
Why else do we care about wood smoke?
• Indoor Air Quality – Old wood stoves are often poorly sealed – Improper installation and ventilation of woodstoves and
fireplaces
• Energy Efficiency/Renewable– Newer stoves are 50% more efficient, use 1/3 less wood,
which is renewable– Potential global warming benefits
• Fire Safety– Creosote build-up in chimney from old stoves is faster
22
Residential Wood Smoke: What is EPA doing?
• Great American Wood Stove Changeout – Partnership program to replace inefficient wood stoves with
cleaner burning technologies
• Outdoor Wood-fired Hydronic Heathers– Helped States develop Model Rule– Partnership with industry to bring cleaner units to market
• Fireplaces– Consensus ASTM Test Method complete– Working on consensus emission standard
