DOE/EA-1673 

Environmental Assessment 

for 

10 CFR 431 Energy Conservation Program for Certain Industrial Equipment: 

Energy Conservation Standards and Test Procedures for Commercial Heating, AirConditioning, and Water-Heating Equipment 

July 2009
8-i 

CHAPTER 8. ENVIRONMENTAL ASSESSMENT

TABLE OF CONTENTS

8.1 INTRODUCTION ............................................................................................................... 8-1

8.2 AIR QUALITY ANALYSIS ............................................................................................... 8-1

8.3 AIR POLLUTANT DESCRIPTIONS ................................................................................ 8-1

8.4 AIR QUALITY REGULATIONS ...................................................................................... 8-3

8.5 Global Climate Change ....................................................................................................... 8-5

8.6 ANALYTICAL METHODS FOR AIR QUALITY ............................................................ 8-7

8.6.1 Carbon Dioxide .................................................................................................... 8-8

8.6.2 Nitrogen Oxides ................................................................................................... 8-8

8.6.3 Sulfur Dioxide ..................................................................................................... 8-9

8.7 EFFECTS ON EMISSIONS ................................................................................................ 8-9

8.8 EFFECTS ON UPSTREAM FUEL-CYCLE EMISSIONS .............................................. 8-17

8.9 WETLAND, ENDANGERED AND THREATENED SPECIES, AND CULTURAL 

RESOURCES .................................................................................................................... 8-17

8.10 ENVIRONMENTAL JUSTICE IMPACTS ...................................................................... 8-17

8.11 NOISE AND AESTHETICS ............................................................................................. 8-18

REFERENCES .......................................................................................................................... 8-19

LIST OF TABLES

Table 8.6.1 Estimated National Average Emissions Factors for Commercial Fuel 

Combustion of Natural Gas and Fuel Oil #2 ....................................................... 8-8

Table 8.7.1 Summary of Cumulative National Emissions Impact for Commercial 

Boilers from 2012 to 2042 for Adopting ASHRAE Standard 90.1-2007 

over the Market Baseline ................................................................................... 8-10

Table 8.7.2 Summary of Cumulative National Emissions Impact for Commercial 

Boilers from 2012 to 2042 for Adoption of Analyzed Higher Standards 

over the ASHRAE Standard 90.1-2007 Levels ................................................. 8-11

Table 8.7.3 Summary of National Emissions Impact for Commercial Boilers from 

2012 to 2042 for Adopting ASHRAE Standard 90.1-2007 over the Market 

Baseline .............................................................................................................. 8-12

Table 8.7.4 Summary of National Emissions Impact for Commercial Boilers from 

2012 to 2042 for Adopting Level 1 over ASHRAE Standard 90.1-2007 .......... 8-13

Table 8.7.5 Summary of National Emissions Impact for Commercial Boilers from 

2012 to 2042 for Adopting Level 2 over ASHRAE Standard 90.1-2007 .......... 8-14

Table 8.7.6 Summary of National Emissions Impact for Commercial Boilers from 

2012 to 2042 for Adopting Level 3 over ASHRAE Standard 90.1-2007 .......... 8-15
8-ii

Table 8.7.7 Summary of National Emissions Impact for Commercial Boilers from 

2012 to 2042 for Adopting Level 4 over ASHRAE Standard 90.1-2007 .......... 8-16
8-1 

CHAPTER 8. ENVIRONMENTAL ASSESSMENT 

8.1 INTRODUCTION

This chapter describes potential environmental effects that may result from amended 

energy conservation standards for certain equipment covered by the American Society of 

Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE)/Illuminating 

Engineering Society of North America (IESNA) Standard 90.1. Such equipment includes 

commercial packaged boilers and water-cooled and evaporatively-cooled commercial package 

air conditioners and heat pumps with a cooling capacity at or above 240,000 Btu/h and less than 

760,000 Btu/h. DOE proposed standards for these two equipment types in a March 20, 2009 (74 

FR 12000). This chapter only describes the potential environmental effects that may result from 

amended energy conservation standards for commercial packaged boilers. DOE did not analyze 

the environmental effects that may results from amended national energy conservation standards 

for water-cooled and evaporatively-cooled commercial package air conditioners and heat pumps 

with a cooling capacity at or above 240,000 Btu/h and less than 760,000 Btu/h because there is 

no equipment currently being manufactured in this equipment class. 

The U.S. Department of Energy (DOE)’s proposed energy conservation standards are not 

site-specific, and would apply to all 50 States and U.S. territories. Therefore, none of the 

proposed standards would affect land uses, cause any direct disturbance to the land, or directly 

affect biological resources, or have any other impact on the human environment in any one area.

All of the potential standard levels analyzed are expected to reduce energy consumption 

in comparison to a baseline. For the purposes of this Environmental Assessment (EA), the 

baseline is defined as how much energy would be consumed if DOE does not adopt any standard 

for commercial boilers.

a

The primary, anticipated environmental impact of revised standard levels is on air quality 

and results from changes in fuel consumption for the equipment examined. Therefore, much of 

this chapter describes the air quality analysis. The latter part of the chapter describes potential 

impacts to other environmental resources. 

 The changes in the demand for fossil fuel, including fuel oil and natural 

gas, and the costs of achieving these savings are the primary drivers in analyzing environmental 

effects. 

8.2 AIR QUALITY ANALYSIS

The primary focus of the environmental analysis is the impact on air quality of amended 

energy conservation standards for commercial boilers. The outcomes of the environmental 

analysis are driven by changes in the quantities of fuel consumed under each of the alternatives. 

8.3 AIR POLLUTANT DESCRIPTIONS 

An air pollutant is any substance in the air that can cause harm to humans or the 

environment. Pollutants may be natural or man-made (i.e., anthropogenic) and may take the form 

 

a See Section 8.7 for additional information on the baseline.
8-2 

of solid particles (i.e., particulates or particulate matter), liquid droplets, or gases.b

Sulfur Dioxide 

 For each of 

the efficiency standards examined in this analysis, DOE calculated total emissions using 

emission coefficients or ratios relating the amount of a particular pollutant emitted per unit of 

source energy consumed. This analysis considers three pollutants: nitrogen oxides (NOx), sulfur 

dioxide (SO2), and carbon dioxide (CO2). A fourth pollutant, mercury (Hg), is emitted in such 

small amounts that analysis of Hg in this EA would be uninformative; as such, DOE does not 

discuss Hg emissions in this EA. 

Sulfur dioxide is a chemical compound that is produced by various natural and industrial 

processes and is key contributor to acid rain. Moreover, sulfur dioxide has been shown to impair 

human health. In addressing SO2 emissions, the Clean Air Act Amendments of 1990 set an SO2 

emissions cap on all power generation, but permitted flexibility among generators through the 

use of emissions allowances and tradable permits. This SO2 trading process (sometimes called 

“cap and trade”) does not, however, cover commercial packaged boilers. Consequently, there is a 

direct SO2 environmental benefit from a reduction in fuel consumption resulting from the 

proposed higher efficiency standards for commercial packaged boilers.

Nitrogen Oxides 

Nitrogen oxides, or NOx, are the generic term for a group of highly reactive gases, all of 

which contain nitrogen and oxygen in varying amounts. Many of the nitrogen oxides are 

colorless and odorless. However, one common pollutant, nitrogen dioxide (NO2), along with 

particles in the air, can often be seen as a reddish-brown layer over many urban areas. NO2 is the 

specific form of NOx reported in this document. NOx is one of the main ingredients involved in 

the formation of ground-level ozone, which can trigger serious respiratory problems. It can 

contribute to the formation of acid rain, and can impair visibility in areas such as national parks. 

NOx also contributes to the formation of fine particles that can impair human health. 

Nitrogen oxides form when fossil fuel is burned at high temperatures, as in a combustion 

process. The primary man-made sources of NOx are motor vehicles, electric utilities, and other 

industrial, commercial, and residential sources that burn fossil fuels. NOx can also be formed 

naturally. Electric utilities account for about 22 percent of NOx emissions in the United States.

Carbon Dioxide

Carbon dioxide (CO2) is not a regulated or criteria pollutant (see below), but it is of 

interest because of its classification as a greenhouse gas (GHG) and its impact on global climate 

change. GHGs trap the sun’s radiation inside the Earth’s atmosphere and either occur naturally in 

the atmosphere or result from human activities. Naturally-occurring GHGs include water vapor, 

CO2, methane (CH4), nitrous oxide (N2O), and ozone (O3). Human activities, however, add to the 

levels of most of these naturally-occurring gases. For example, CO2 is emitted to the atmosphere 

when solid waste, fossil fuels (oil, natural gas, and coal), wood, and wood products are burned. 

 

b More information on air pollution characteristics and regulations is available on the U.S. Environmental Protection 

Agency (EPA)’s website at www.epa.gov. 
8-3 

During the past 20 years, about three-quarters of anthropogenic (i.e., human-made) CO2

emissions resulted from burning fossil fuels.

Concentrations of CO2 in the atmosphere are naturally regulated by numerous processes, 

collectively known as the “carbon cycle.” The movement of carbon between the atmosphere and 

the land and oceans is dominated by natural processes, such as plant photosynthesis. While these 

natural processes can absorb some of the anthropogenic CO2 emissions produced each year, 

billions of metric tons are added to the atmosphere annually. The Earth’s imbalance between 

emissions and absorption results in the continuing growth of GHGs in the atmosphere, causing 

surface air temperatures and sub-surface ocean temperatures to rise. In the United States, CO2 

emissions account for 85.4 percent of total U.S. GHG emissions.1

8.4 AIR QUALITY REGULATIONS 

 

DOE prepared this EA pursuant to the National Environmental Policy Act of 1969—also 

known as NEPA (42 U.S.C. 4321 et seq.) —the regulations of the Council on Environmental 

Quality (40 CFR parts 1500-1508), and DOE’s regulations for compliance with NEPA 

(10 CFR part 1021). This EA assesses environmental impacts from alternate standard levels 

analyzed for commercial packaged boilers based on the results of the national energy savings 

analysis (see chapter 7). Standards for water-cooled and evaporatively-cooled commercial 

package air conditioners and heat pumps with a cooling capacity at or above 240,000 Btu/h and 

less than 760,000 Btu/h were also considered in this rule; however, since no products could be 

identified on the market in this class, no subsequent energy or environmental impacts were 

considered in this EA.

By way of background, title III of the Energy Policy and Conservation Act (EPCA) sets 

forth a variety of provisions designed to improve energy efficiency. Part A of title III (42 U.S.C. 

6291-6309) provides for the Energy Conservation Program for Consumer Products Other Than 

Automobiles. Part A-1 of title III (42 U.S.C. 6311-6317) provides for the Energy Conservation 

Program for Certain Industrial Equipment. In general, the program covers consumer products 

and certain commercial products (referred to hereafter as “covered products”), including 

commercial furnaces and boilers. EPCA contains mandatory energy conservation standards for 

commercial heating, air-conditioning, and water-heating equipment (42 U.S.C. 6313(a)). 

Specifically, the statute sets standards for small, large, and very large commercial package airconditioning and heating equipment, packaged terminal air conditioners (PTACs) and packaged 

terminal heat pumps (PTHPs), warm air furnaces, packaged boilers, storage water heaters, and 

unfired hot water storage tanks. In doing so, EPCA established Federal energy conservation 

standards that generally correspond to the levels in the American Society of Heating, 

Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 90.1, as in effect on October 

24, 1992 (i.e., ASHRAE Standard 90.1-1989), for each type of covered equipment listed in 42 

U.S.C. 6313(a). 

Congress further directed DOE through EPCA to consider amending the existing Federal 

energy conservation standard for each type of equipment listed, each time ASHRAE Standard 

90.1 is amended with respect to such equipment (42 U.S.C. 6313(a)(6)(A)). For each type of 

equipment, EPCA directs that if ASHRAE Standard 90.1 is amended, DOE must adopt amended 

standards at the new efficiency level in ASHRAE Standard 90.1, unless clear and convincing 
8-4 

evidence supports a determination that adoption of a more stringent level would produce 

significant additional energy savings and be technologically feasible and economically justified 

(42 U.S.C. 6313(a)(6)(A)(ii)). EPCA precludes DOE from adopting any standard that would not 

result in significant conservation of energy (42 U.S.C 6295(o)(3); 6313(a)(6); 6316(a)). 

The Clean Air Act Amendments of 1990 list 188 toxic air pollutants that the U.S. 

Environmental Protection Agency (EPA) is required to control. EPA has set national ambient air 

quality standards for six common pollutants (also referred to as “criteria” pollutants), two of 

which are SO2 and NOx (42 U.S.C. 7408-7410).c

NOx emissions from 28 eastern States and the District of Columbia (D.C.) are limited 

under the Clean Air Interstate Rule, published in the Federal Register on May 12, 2005. 

Although the rule has been remanded to EPA by the D.C. Circuit, it will remain in effect until it 

is replaced by a rule consistent with the Court's opinion in North Carolina v. EPA.

 Also, the Clean Air Act Amendments of 1990 

gave EPA the authority to control acidification and to require operators of electric power plants 

to reduce emissions of SO2 and NOx. Title IV of the Clean Air Act established a cap-and-trade 

program for SO2 that is intended to help control acid rain. This cap-and-trade program serves as 

a model for more recent programs with similar features. However, as a practical matter, 

commercial packaged boilers are in general not subject to the emission caps under the Clean Air 

Act amendments, for the reasons explained below. 

d Under 

CAIR, States must achieve the required emission reductions using one of two compliance 

options: (1) meet an emission budget for each regulated State by requiring power plants to 

participate in an EPA-administered interstate cap-and-trade system that caps emissions in two 

stages, or (2) meet an individual State emissions budget through measures of the State’s 

choosing. In general, however, CAIR basically covers two general classes of NOx emitters: (1) 

stationary, fossil-fuel-fired boilers or stationary, fossil-fuel-fired combustion turbines serving 

generators with nameplate capacity of more than 25 MW of electricity and producing that 

electricity for sale, and (2) any unit that has a maximum design heat input rate of greater than 

250 million Btu/h (40 CFR 96.4).e

The EPA’s New Source Performance Standards (NSPS) limit, among other things, SO2 

emission from boilers built after a certain date. In particular, 40 CFR part 60 subpart Dc, 

 Commercial packaged boilers are smaller than this second 

limit and are not used for commercial power production. Hence, requirements of the CAIR do 

not apply to commercial packaged boilers. 

Standards of Performance for Small Industrial-Commercial-Institutional Steam Generating 

Units

 

c In 2007, the U.S. Supreme Court ruled that the EPA had authority to regulate CO2 emissions. (Massachusetts v. 

Environmental Protection Agency, 549 U.S. 497 (2007). EPA does not currently regulate CO2, but the agency has 

been considering introduction of CO2 emissions regulations.

, requires that small industrial-commercial-institutional steam generating units must limit 

the allowable sulfur content in fuel oil to 0.5 weight percent for any steam-generating unit that 

e On July 11, 2008, the U.S. Court of Appeals for the District of Columbia Circuit (D.C. Circuit) issued its decision 

in North Carolina v. Environmental Protection Agency, in which the Court vacated the CAIR rule. 531 F.3d 896 

(D.C. Cir. 2008). However, in a December 23, 2008 opinion, the same panel of the D.C. Circuit reinstated the CAIR 

rule pending EPA’s compliance with its July 11, 2008 ruling. 550 F.3d 1176 (D.C. Cir. 2008)(remand of vacatur). 

As such, CAIR’s trading programs and target deadlines remain in place at present; however, the long term prospects 

for and shape of those trading programs are unknown. 
8-5 

has a maximum design heat input capacity of 100 million British thermal units (Btu) per hour 

and is constructed, modified, or reconstructed after June 9, 1989. (40 CFR 60.40c-60.48c) While 

commercial packaged boilers that have a maximum design heat input capacity of 100 million Btu 

per hour would be an extremely small subset of all boilers being considered in this rule, some 

would likely be covered. In addition, the NSPS does help to limit the quantity of SO2 released 

into the atmosphere by limiting the market for fuel oils with higher sulfur content. Note, NSPS 

defines a steam generating unit to be a device that combusts any fuel and produces steam or 

heats water or any other heat transfer medium. This term also includes any duct burner that 

combusts fuel and is part of a combined cycle system. This term does not include process heaters

.(40 CFR 60.40c-60.48c) 

8.5 GLOBAL CLIMATE CHANGE 

Climate change has evolved into a matter of global concern because it is expected to have 

widespread adverse effects on natural resources and systems. A growing body of evidence points 

to anthropogenic sources of GHGs, such as carbon dioxide (CO2), as major contributors to 

climate change. Because this rule, if finalized, will likely decrease CO2 emission rates from the 

fossil fuel sector in the United States, the Department here examines the impacts and causes of 

climate change and then the potential impact of the rule on CO2 emissions and global warming. 

Impacts of Climate Change on the Environment 

Climate is usually defined as the average weather, over a period ranging from months to 

many years. Climate change refers to a change in the state of the climate, which is identifiable 

through changes in the mean and/or the variability of its properties (e.g., temperature or 

precipitation) over an extended period, typically decades or longer. 

The World Meteorological Organization and United Nations Environment Programme 

(UNEP) established the Intergovernmental Panel on Climate Change (IPCC) to provide an 

objective source of information about climate change. According to the IPCC Fourth Assessment 

Report (IPCC Report), published in 2007, climate change is consistent with observed changes to 

the world’s natural systems; the IPCC expects these changes to continue.2

Changes that are consistent with warming include: (1) warming of the world’s oceans to a 

depth of 3000 meters; (2) global average sea level rise at an average rate of 1.8 mm per year 

from 1961 to 2003; (3) loss of annual average Arctic sea ice at a rate of 2.7 percent per decade; 

(4) changes in wind patterns that affect extra-tropical storm tracks and temperature patterns; 

(5) increases in intense precipitation in some parts of the world as well as increased drought and 

more frequent heat waves in many locations worldwide; and (6) numerous ecological changes.2

Looking forward, the IPCC describes continued global warming of about 0.2 °C per 

decade for the next two decades under a wide range of emission scenarios for CO2, other GHGs, 

and aerosols. After that period, the rate of increase is less certain. The IPCC Report describes 

cumulative increases in average global temperatures of about 1.1 °C to 6.4 °C at the end of the 

century relative to today. These increases vary depending on the model and emissions scenarios.2

The IPCC Report describes incremental impacts associated with the rise in temperature. 

At ranges of incremental increases to the global average temperature, IPCC reports, with either 
8-6 

high or very high confidence, that there is likely to be an increasing degree of impacts (e.g., coral 

reef bleaching, loss of wildlife habitat, loss to specific ecosystems, and negative yield impacts 

for major cereal crops in the tropics), but also projects likely beneficial impacts on crop yields in 

temperate regions.

2

Causes of Climate Change 

The IPCC Report states that the world has warmed by about 0.74 °C in the last 100 years. 

The IPCC Report finds that most of the temperature increase since the mid-20th century is very 

likely due to the increase in anthropogenic concentrations of CO2 and other long-lived GHGs 

(e.g., methane and nitrous oxide in the atmosphere) rather than from natural causes.3

Increasing the CO2 concentration partially blocks the earth’s re-radiation of captured 

solar energy in the infrared band, inhibits the radiant cooling of the earth, and thereby alters the 

energy balance of the planet, which gradually increases its average temperature. The IPCC 

Report estimates that CO2 currently makes up about 77 percent of the total CO2-equivalentf

global warming potential in GHGs emitted from human activities, with the vast majority 

(74 percent) of the CO2 attributable to fossil fuel use. For the future, the IPCC Report describes a 

wide range of GHG emissions scenarios. However, under each scenario, CO2 would continue to 

comprise above 70 percent of the total global warming potential.4

Stabilization of CO2 Concentrations 

Unlike many traditional air pollutants, CO2 mixes thoroughly in the entire atmosphere 

and is long-lived. The residence time of CO2 in the atmosphere is long compared to the emission 

processes. Therefore, the global cumulative emissions of CO2 over long periods determine CO2 

concentrations because it takes hundreds of years for natural processes to remove the CO2. 

Globally, 49 billion metric tons of CO2–equivalent, anthropogenic (man-made) GHGs are 

emitted every year. Of this annual total, fossil fuels contribute about 29 billion metric tons of 

CO2.

g

Researchers have focused on considering atmospheric CO2 concentrations that likely will 

result in some level of global climate stabilization, and the emission rates associated with 

achieving the “stabilizing” concentrations by particular dates. They associate these stabilized 

CO2 concentrations with temperature increases that plateau in a defined range. For example, at 

the low end, the IPCC Report scenarios target CO2-stabilized concentrations at a range between 

350 ppm and 400 ppm (essentially today’s value), because of climate inertia, concentrations in 

this low-end range would still result in temperatures projected to increase 2.0 °C to 2.4 °C above 

pre-industrial levels

, 4 

h

 

f GHGs differ in their warming influence (radiative forcing) on a global climate system due to their different 

radiative properties and lifetimes in the atmosphere. These warming influences may be expressed through a common 

metric based on the radiative forcing of CO2 (i.e., CO2-equivalent). CO2 equivalent emission is the amount of CO2

emission that would cause the same-time integrated radiative forcing, over a given time horizon, as an emitted 

amount of other long-lived GHG or mixture of GHGs.

 (about 1.3 oC to 1.7 oC above today’s levels). To achieve concentrations 

between 350 ppm to 400 ppm, the IPCC scenarios present that there would have to be a rapid 

g Other non-fossil-fuel contributors include CO2 emissions from deforestation and decay from agriculture biomass, 

agricultural and industrial emissions of methane, and emissions of nitrous oxide and fluorocarbons.

h IPCC Working Group 3, Table TS 2.
8-7 

downward trend in total annual global emissions of GHGs to levels that are 50 percent to 

85 percent below today’s annual emission rates by no later than 2050. Since it is assumed that 

there would continue to be growth in global populations and substantial increases in economic 

production, the scenarios identify required reductions in GHG emissions intensity (emissions per 

unit of output) of more than 90 percent. However, even at these rates, the scenarios describe 

some warming, and some climate change is projected due to already accumulated CO2 and 

GHGs in the atmosphere.4

As computed for the AEO 2008 reference casei

8.6 ANALYTICAL METHODS FOR AIR QUALITY 

, the cumulative U.S. energy-related CO2

emissions between 2012 and 2042 are described at about 209 billion metric tons. 

To analyze the effect of proposed efficiency standards on air resources, DOE used 

accepted EPA emission coefficients. In DOE rules related to electrically fueled appliances and 

equipment, typically a modified version of the National Energy Modeling System (NEMS), 

called NEMS-BT (“BT” stands for Building Technologies), is used to determine the emissions 

that are a result of proposed energy efficiency standards. For the EA, the output is the forecasted 

physical emissions. The NEMS-BT tracks CO2 and NOx emissions using a detailed module that 

provides broad coverage of all sectors collectively and includes interactive effects. However, 

NEMS-BT does not independently consider commercial emissions of NOx and SO2 from the 

combustion of natural gas and heating fuel oil. Because an efficiency standard could result in 

changes in these emissions, DOE performed a limited literature search to determine appropriate 

emissions factors for CO2, NOx, and SO2 from commercial appliances. Specifically, this work 

focuses on establishing emissions coefficients appropriate to commercial packaged boilers for 

use in calculating emissions impacts from proposed efficiency standards. 

The review attempts to confirm that the emissions factors available from the EPA for 

CO2, NOx, and SO2 from natural gas and external combustion of #2 fuel oil (e.g., in boilers, 

furnaces) for commercial boilers are representative of the United States.

6

 The EPA cautions 

against the use of these emissions factors as representative of actual emissions. Rather, they are 

to be used, and are used here, as general approximations of national average emissions factors in 

order to calculate emissions impacts that result from activities such as proposed commercial 

packaged boiler energy efficiency standards. 

For each efficiency level, DOE calculated the emissions based on the annual fuel 

consumption for the different classes of commercial boilers and furnaces. The EA considers 

impacts from two pollutants that are listed under the Clean Air Act (NOx and SO2) and are 

regulated under National Ambient Air Quality Standards (NAAQS). It also considers the impacts 

of CO2. An air pollutant is any substance in the air that can cause harm to humans or the 

environment; the NAAQS regulates emissions of certain air pollutants. Pollutants may be natural 

or man-made and may take the form of solid particles, liquid droplets, or gases. Table 8.6.1

summarizes the emissions factor estimates for the two fuels of interest. The values presented 

here are based on the EPA’s assessment of combustion emissions. These emissions estimates 

represent an approximate emissions factor for the United States as a whole. They are used, 

 

i

 See www.eia.doe.gov/oiaf/archive/aeo08/index.html. 
8-8 

together with estimated energy savings, to calculate end-use site emissions impacts. The 

emissions factors discussed in this analysis are represented as mass (kg) of the specific emission 

of interest per million Btu of energy input to the commercial packaged boiler. 

Table 8.6.1 Estimated National Average Emissions Factors for Commercial Fuel Combustion 

of Natural Gas and Fuel Oil #2 

CO2 (kg/million Btu) NOx (kg/million Btu) SO2 (kg/million Btu)

Natural Gas 53.353 0.084 0.000

Fuel Oil #2 72.756 0.082 0.256

8.6.1 Carbon Dioxide 

The CO2 estimates in Table 8.6.1 are based on EPA’s assessment of CO2 combustion from 

natural gas and fuel oil #2 use. Other sources of information include DOE’s Energy Information 

Administration (EIA) and the Canada’s Environment Canada agency.7, 8 All agree to within ± 2.0 

percent of EPA’s assessed estimate of CO2 emissions. EPA’s CO2 emissions factors for natural 

gas and fuel oil #2 combustion are, therefore, a reasonable evaluation of averaged CO2 emissions 

rates. In the case of both fuels, the estimated CO2 emission rates assume 99 percent (or higher) 

conversion of fuel carbon content to CO2. 

The Beneficial Impact of the Rule on CO2 Emissions 

If finalized, it is anticipated that the rule will reduce energy-related emissions, 

particularly those associated with energy consumption in buildings., The EIA reports in its 2008 

Annual Energy Outlook (AEO 2008) that U.S. annual energy-related emissions of CO2 in 2005 

were about 5.98 billion metric tons (about 20 percent of the world energy-related CO2 emissions 

and about 12 percent of total global GHG emissions), of which 2.32 billion tons were attributed 

to residential and commercial buildings sector (including related energy–using equipment, such 

as commercial packaged boilers). Most of the GHG emissions attributed to residential and 

commercial buildings are emitted from fossil fuel-fired power plants that generate electricity 

used in this sector, although some emissions are the results of direct combustion equipment such 

as commercial boilers. In the AEO 2008 reference case, EIA projected that annual energy-related 

CO2 emissions would grow from 6.0 billion metric tons in 2005 to 6.85 billion metric tons in 

2030, an increase of 14.5 percent, while emissions attributable to buildings would grow to 2.92 

billion tons, an increase of 26.1 percent. 

8.6.2 Nitrogen Oxides

The NOx estimates in Table 8.6.1 are based on EPA’s assessment of NOx combustion 

from natural gas and fuel oil #2 use. NOx emissions from natural gas combustion were 

specifically collected for large scale (>100 million Btu/hr of heat input) combustor types. In the 

case of fuel oil, NOx formation in combustion processes is significantly more complex than the 

formation of SO2 or CO2. NOx can result from oxidization of N2. Fuel is one source of N2, but 

the larger source is N2 is through the combustion-air intake. This process is sensitive to 

combustion chemistry, and therefore, quite variable. It also implies that appliance design can 

lower NOx emissions. NOx is both an acid precipitation and ozone (O3) precursor, but because 

commercial appliances are a relatively small and dispersed (i.e., hard to monitor) source, 
8-9 

regulation of these emissions tends to play a small role in government or private sector 

orchestrated NOx control strategies. The O3 hazards of NOx emissions are highly variable both 

spatially and over time, as weather conditions favor or disfavor O3 formation. Local NOx

emissions rules and State Implementation Plans will control NOx to different degrees in different 

jurisdictions. In fact, sources of NOx in certain States are subject to the Clean Air Interstate Rule, 

which gives States the option to participate in a trading scheme. 

8.6.3 Sulfur Dioxide

Sulfur dioxide emissions from natural gas combustion are assumed to be zero. In the case 

of fuel oil, emissions of SO2 are a direct function of the sulfur content of the fuel. Individual 

State and local regulations limiting the amount of sulfur in fuel oil, however, reveal substantial 

variability in SO2 emissions factors. A literature survey suggested that an assumed 0.5 percent 

sulfur content by weight resulted in a conservative and representative estimate for the national 

average sulfur content for fuel oil. In addition, this 0.5 percent sulfur content by weight quantity 

was also referenced in the requirements of EPA’s New Source Performance Standards. (40 CFR 

60.40c-60.48c).5 A straight multiplication of the fuel energy content and the percentage of sulfur 

content in the fuel provides the emissions factor as per the EPA’s Compilation of Air Pollutant 

Emission Factors (AP-42) guidelines.6 Other references provided similar figures for emission 

factors.7,8

8.7 EFFECTS ON EMISSIONS

This EA examines the environmental impact that standards would have based upon the 

efficiency levels shown in ASHRAE Standard 90.1-2007, and up to four higher efficiency levels. 

Generally, in reporting the impacts (including the environmental impacts) of setting standards, 

DOE compares the proposed standards against a no action alternative. Each efficiency level 

examined is considered an alternative action whose costs and benefits are compared with the noaction alternative. In the case of commercial packaged boilers, however, DOE is required by law 

to set standards at the levels indicated by a revised version of ASHRAE Standard 90.1 unless it 

can show by clear and convincing evidence that more stringent efficiency standards are 

technologically feasible and economically justified and would result in significant additional 

energy savings. (42 U.S.C. 6313(a)(6)(A)(ii)) For this reason, DOE is legally bound to adopt 

efficiency levels that meet or exceed those shown in ASHRAE Standard 90.1-2007. 

However, for this EA, DOE has chosen to report impacts in two ways. In examining the 

environmental impact for DOE to adopt standards equivalent to the requirements in ASHRAE 

Standard 90.1-2007, DOE has determined that it will analyze and report these impacts against a 

no-new-standard scenario (i.e., a “no action” scenario). Under this scenario, DOE assumed a 

base case in which future shipments in this no-new-standard scenario reflect that of the current 

market. In reporting the impacts of DOE’s adoption of efficiency levels higher than ASHRAE 

Standard 90.1-2007 (i.e., efficiency levels 1, 2, 3, and 4), DOE has determined that the 

environmental impacts should be provided as possible impacts over a separate base case that 

assumes a standard set at the minimum that DOE can legally adopt (i.e., ASHRAE Standard 

90.1-2007 efficiency levels). 
8-10

Table 8.7.1 shows the cumulative emissions impacts between the no-new-standard base 

case (also referred to here as the market baseline) and adopting the ASHRAE Standard 90.1-

2007 efficiency levels over the time range of 2012 to 2042. In general, the cumulative impact (in 

terms of emissions reductions) over the market base case is relatively small. Nevertheless, all 

equipment classes exhibit emission savings with the exception of large, gas-fired, hot water

equipment and large, oil-fired, steam equipment since essentially all equipment sold today meets 

the ASHRAE level. In addition, no natural gas consuming equipment shows SO2 savings since 

natural gas has small and essentially negligible quantities of sulfur.

Table 8.7.1 Summary of Cumulative National Emissions Impact for Commercial Boilers 

from 2012 to 2042 for Adopting ASHRAE Standard 90.1-2007 over the Market Baseline 

Equipment Class

Cumulative National Emissions 

Impact from 2012 to 2042

CO2

(metric kilotons)

NOx

(short tons)

SO2

(short tons)

Small, Gas-fired, Hot Water (642) (1,120) 0 

Small, Gas-fired, Steam, All Except Natural Draft (29) (51) 0

Small, Gas-fired, Steam, Natural Draft (1,834) (3,200) 0 

Small, Oil-fired, Hot Water (645) (797) (2,501)

Small, Oil-fired, Steam (311) (384) (1,206)

Large, Gas-fired, Hot Water (282) (491) 0

Large, Gas-fired, Steam, All Except Natural Draft (168) (294) 0 

Large, Gas-fired, Steam, Natural Draft (1,404) (2,451) 0

Large, Oil-fired, Hot Water 0 0 0 

Large, Oil-fired, Steam 0 0 0

*Negative values, shown in parentheses, indicate emissions reductions compared with the base case

Table 8.7.2 shows the cumulative emissions impacts for selecting standards higher than 

the ASHRAE Standard 90.1-2007 efficiency levels over the time range of 2012 to 2042. With 

the exception of a few equipment classes at efficiency level 1, all equipment classes exhibit 

greater cumulative emission savings when going beyond the ASHRAE Standard 90.1-2007 level. 

Table 8.7.3 shows the annual emission impact for selecting the ASHRAE Standard 90.1-

2007 over the market baseline over the time range 2012 to 2042 for selected years. Lastly, 

Table 8.7.4 to Table 8.7.7 show the annual emission impact for selecting higher energy 

efficiency levels above the ASHRAE Standard 90.1-2007 levels over the time range 2012 to 

2042. 
ASHRAE_90 1_EA_TSD_05-22-09.doc

8-11

Table 8.7.2 Summary of Cumulative National Emissions Impact for Commercial Boilers from 2012 to 2042 for Adoption of 

Analyzed Higher Standards over the ASHRAE Standard 90.1-2007 Levels 

Equipment Class

Cumulative National Emissions Impact from 2012 to 2042 *,**

Efficiency Level 1 Efficiency Level 2 Efficiency Level 3 Efficiency Level 4

CO2 

(metric 

kilotons)

NOx 

(short 

tons)

SO2 

(short 

tons)

CO2 

(metric 

kilotons)

NOx 

(short 

tons)

SO2 

(short 

tons)

CO2 

(metric 

kilotons)

NOx

(short 

tons)

SO2 

(short 

tons)

CO2 

(metric 

kilotons)

NOx

(short 

tons)

SO2

(short 

tons)

Small, Gas-fired, Hot 

Water (1,164.80) (2,032.96) 0.00 (3,837.02) (6,696.86) 0.00 (7,467.22) (13,032.73) 0.00 (11,289.11) (19,703.18) 0.00 

Small, Gas-fired, 

Steam, All Except 

natural Draft

3.42 5.97 0.00 (757.85) (1,322.70) 0.00 (1,582.83) (2,762.56) 0.00 (2,414.52) (4,214.12) 0.00 

Small, Gas-fired, 

Steam, Natural Draft 306.90 535.64 0.00 (843.98) (1,473.03) 0.00 (2,246.26) (3,920.45) 0.00 na na na 

Small, Oil-fired, Hot 

Water (1,111.58) (1,373.66) (4,313.28) (2,465.77) (3,047.14) (9,568.01) (4,124.98) (5,097.54) (16,006.27) na na na 

Small, Oil-fired, 

Steam (668.24) (825.80) (2,593.01) (1,925.38) (2,379.33) (7,471.11) (4,931.27) (6,093.94) (19,134.98) na na na 

Large, Gas-fired, Hot 

Water (759.26) (1,325.15) 0.00 (1,978.14) (3,452.49) 0.00 (3,254.87) (5,680.80) 0.00 (9,375.49) (16,363.29) 0.00 

Large, Gas-fired, 

Steam, All Except 

Natural Draft

(1,156.43) (2,018.34) 0.00 (3,357.69) (5,860.26) 0.00 (5,596.15) (9,767.10) 0.00 (7,869.37) (13,734.61) 0.00 

Large, Gas-fired, 

Steam, Natural Draft 1,153.20 2,012.70 0.00 (86.43) (150.85) 0.00 (1,686.64) (2,943.74) 0.00 (3,579.41) (6,247.24) 0.00 

Large, Oil-fired, Hot 

Water (980.92) (1,212.19) (3,806.29) (1,730.07) (2,137.98) (6,713.25) (2,461.80) (3,042.23) (9,552.60) na na na 

Large, Oil-fired, 

Steam (2,857.53) (3,531.27) (11,088.17) (7,707.40) (9,524.61) (29,907.28) (14,414.46) (17,813.03) (55,932.91) (29,797.58) (36,823.10) (115,624.53)

*Negative values, shown in parentheses, indicate emissions savings over the base case

**na indicates that the equipment class did not have an Efficiency Level 4
ASHRAE_90 1_EA_TSD_05-22-09.doc

8-12

Table 8.7.3 Summary of National Emissions Impact for Commercial Boilers from 2012 to 2042 for Adopting ASHRAE 

Standard 90.1-2007 over the Market Baseline 

Emission Impact for Adopting ASHRAE Standard 90.1-2007 Over the Market Baseline*

2015 2020 2025 2030 2035 2040 2042

Small, Gas-fired, Hot Water

CO2 (metric kilotons/year) (4.54) (10.53) (16.85) (23.70) (31.55) (40.80) (44.94)

NOx (short tons/year) (7.93) (18.37) (29.40) (41.36) (55.06) (71.21) (78.43)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Gas-fired, Steam, All Except 

natural Draft 

CO2 (metric kilotons/year) (0.48) (0.77) (0.77) (1.08) (1.44) (1.86) (2.05)

NOx (short tons/year) (0.84) (1.34) (1.34) (1.88) (2.51) (3.24) (3.57)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Gas-fired, Steam, Natural Draft

CO2 (metric kilotons/year) (6.05) (11.15) (35.51) (66.61) (102.30) (144.39) (163.18)

NOx (short tons/year) (10.56) (19.47) (61.97) (116.26) (178.55) (252.00) (284.80)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Oil-fired, Hot Water

CO2 (metric kilotons/year) (4.56) (10.57) (16.92) (23.79) (31.68) (40.97) (45.12)

NOx (short tons/year) (5.64) (13.06) (20.91) (29.40) (39.14) (50.63) (55.76)

SO2 (short tons/year) (17.70) (41.02) (65.64) (92.33) (122.91) (158.98) (175.09)

Small, Oil-fired, Steam

CO2 (metric kilotons/year) (2.20) (5.10) (8.16) (11.48) (15.28) (19.76) (21.76)

NOx (short tons/year) (2.72) (6.30) (10.08) (14.18) (18.88) (24.42) (26.89)

SO2 (short tons/year) (8.53) (19.78) (31.66) (44.53) (59.28) (76.67) (84.44)

Large, Gas-fired, Hot Water 

CO2 (metric kilotons/year) (1.99) (4.62) (7.39) (10.39) (13.83) (17.89) (19.71)

NOx (short tons/year) (3.48) (8.06) (12.89) (18.14) (24.14) (31.23) (34.39)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Gas-fired, Steam, All Except 

Natural Draft 

CO2 (metric kilotons/year) (1.19) (2.76) (4.41) (6.21) (8.26) (10.69) (11.77)

NOx (short tons/year) (2.08) (4.81) (7.70) (10.84) (14.42) (18.66) (20.55)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Gas-fired, Steam, Natural Draft

CO2 (metric kilotons/year) (0.41) 0.57 (21.16) (50.67) (84.16) (123.12) (140.37)

NOx (short tons/year) (0.71) 1.00 (36.92) (88.43) (146.89) (214.88) (245.00)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Oil-fired, Hot Water

CO2 (metric kilotons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

NOx (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Oil-fired, Steam

CO2 (metric kilotons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

NOx (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 
ASHRAE_90 1_EA_TSD_05-22-09.doc

8-13

Table 8.7.4 Summary of National Emissions Impact for Commercial Boilers from 2012 to 2042 for Adopting Level 1 over 

ASHRAE Standard 90.1-2007 

Emission Impact for Adopting Level 1 Over ASHRAE Standard 90.1-2007*

2015 2020 2025 2030 2035 2040 2042

Small, Gas-fired, Hot Water

CO2 (metric kilotons/year) (2.51) (15.44) (29.10) (43.91) (60.89) (80.92) (89.87)

NOx (short tons/year) (4.38) (26.95) (50.79) (76.64) (106.27) (141.23) (156.84)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Gas-fired, Steam, All Except 

Natural Draft

CO2 (metric kilotons/year) 0.11 0.11 0.11 0.11 0.11 0.11 0.11 

NOx (short tons/year) 0.20 0.20 0.20 0.20 0.20 0.20 0.20 

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Gas-fired, Steam, Natural Draft

CO2 (metric kilotons/year) (3.67) (12.38) (4.44) 9.32 25.13 43.78 52.10 

NOx (short tons/year) (6.41) (21.60) (7.75) 16.27 43.87 76.41 90.93 

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Oil-fired, Hot Water 

CO2 (metric kilotons/year) (2.29) (14.67) (27.74) (41.92) (58.18) (77.35) (85.91)

NOx (short tons/year) (2.83) (18.12) (34.28) (51.80) (71.89) (95.59) (106.17)

SO2 (short tons/year) (8.88) (56.91) (107.64) (162.67) (225.75) (300.14) (333.37)

Small, Oil-fired, Steam

CO2 (metric kilotons/year) (1.63) (8.98) (16.74) (25.16) (34.81) (46.19) (51.27)

NOx (short tons/year) (2.02) (11.10) (20.69) (31.09) (43.02) (57.08) (63.36)

SO2 (short tons/year) (6.34) (34.85) (64.97) (97.63) (135.07) (179.23) (198.96)

Large, Gas-fired, Hot Water

CO2 (metric kilotons/year) (2.10) (10.36) (19.09) (28.55) (39.40) (52.19) (57.91)

NOx (short tons/year) (3.66) (18.08) (33.31) (49.83) (68.76) (91.09) (101.07)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Gas-fired, Steam, All Except 

Natural Draft

CO2 (metric kilotons/year) (4.07) (16.34) (29.29) (43.34) (59.45) (78.44) (86.93)

NOx (short tons/year) (7.10) (28.51) (51.13) (75.65) (103.76) (136.90) (151.71)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Gas-fired, Steam, Natural Draft

CO2 (metric kilotons/year) (1.15) (6.38) 13.03 40.71 72.48 109.95 126.68 

NOx (short tons/year) (2.00) (11.13) 22.73 71.04 126.50 191.90 221.10 

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Oil-fired, Hot Water

CO2 (metric kilotons/year) (3.93) (14.16) (24.97) (36.69) (50.12) (65.96) (73.04)

NOx (short tons/year) (4.86) (17.50) (30.86) (45.34) (61.94) (81.51) (90.26)

SO2 (short tons/year) (15.26) (54.96) (96.90) (142.36) (194.48) (255.95) (283.41)

Large, Oil-fired, Steam 

CO2 (metric kilotons/year) (11.46) (41.26) (72.75) (106.88) (146.01) (192.15) (212.77)

NOx (short tons/year) (14.16) (50.99) (89.90) (132.08) (180.43) (237.45) (262.93)

SO2 (short tons/year) (44.45) (160.11) (282.28) (414.73) (566.55) (745.60) (825.60)
ASHRAE_90 1_EA_TSD_05-22-09.doc

8-14

Table 8.7.5 Summary of National Emissions Impact for Commercial Boilers from 2012 to 2042 for Adopting Level 2 over 

ASHRAE Standard 90.1-2007 

Emission Impact for Adopting Level 2 Over ASHRAE Standard 90.1-2007

2015 2020 2025 2030 2035 2040 2042

Small, Gas-fired, Hot Water

CO2 (metric kilotons/year) (13.22) (54.03) (97.13) (143.86) (197.43) (260.61) (288.83)

NOx (short tons/year) (23.08) (94.29) (169.52) (251.08) (344.58) (454.84) (504.10)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Gas-fired, Steam, All Except 

natural Draft

CO2 (metric kilotons/year) (10.88) (19.27) (19.27) (28.36) (38.79) (51.08) (56.57)

NOx (short tons/year) (18.99) (33.63) (33.63) (49.50) (67.69) (89.15) (98.73)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Gas-fired, Steam, Natural Draft

CO2 (metric kilotons/year) (10.63) (29.00) (33.74) (33.72) (33.67) (33.61) (33.60)

NOx (short tons/year) (18.56) (50.61) (58.88) (58.86) (58.77) (58.66) (58.63)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Oil-fired, Hot Water 

CO2 (metric kilotons/year) (7.72) (34.22) (62.22) (92.57) (127.37) (168.41) (186.75)

NOx (short tons/year) (9.54) (42.29) (76.88) (114.40) (157.40) (208.12) (230.77)

SO2 (short tons/year) (29.94) (132.78) (241.41) (359.21) (494.24) (653.48) (724.63)

Small, Oil-fired, Steam

CO2 (metric kilotons/year) (6.67) (27.13) (48.75) (72.18) (99.04) (130.72) (144.88)

NOx (short tons/year) (8.25) (33.53) (60.24) (89.20) (122.39) (161.54) (179.04)

SO2 (short tons/year) (25.89) (105.29) (189.15) (280.08) (384.32) (507.25) (562.17)

Large, Gas-fired, Hot Water

CO2 (metric kilotons/year) (6.98) (27.96) (50.12) (74.14) (101.68) (134.15) (148.66)

NOx (short tons/year) (12.19) (48.80) (87.47) (129.39) (177.46) (234.14) (259.46)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Gas-fired, Steam, All Except 

Natural Draft

CO2 (metric kilotons/year) (12.89) (48.12) (85.33) (125.68) (171.92) (226.46) (250.83)

NOx (short tons/year) (22.50) (83.99) (148.93) (219.35) (300.06) (395.25) (437.77)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Gas-fired, Steam, Natural Draft

CO2 (metric kilotons/year) (6.24) (24.79) (19.58) (6.94) 8.94 29.55 39.23 

NOx (short tons/year) (10.89) (43.27) (34.18) (12.11) 15.60 51.58 68.47 

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Oil-fired, Hot Water

CO2 (metric kilotons/year) (6.94) (24.98) (44.04) (64.71) (88.40) (116.34) (128.82)

NOx (short tons/year) (8.57) (30.87) (54.43) (79.97) (109.24) (143.76) (159.19)

SO2 (short tons/year) (26.91) (96.94) (170.90) (251.09) (343.01) (451.42) (499.85)

Large, Oil-fired, Steam 

CO2 (metric kilotons/year) (30.90) (111.29) (196.21) (288.28) (393.81) (518.27) (573.88)

NOx (short tons/year) (38.18) (137.53) (242.47) (356.24) (486.66) (640.46) (709.18)

SO2 (short tons/year) (119.89) (431.85) (761.36) (1,118.61) (1,528.11) (2,011.05) (2,226.82)
ASHRAE_90 1_EA_TSD_05-22-09.doc

8-15

Table 8.7.6 Summary of National Emissions Impact for Commercial Boilers from 2012 to 2042 for Adopting Level 3 over 

ASHRAE Standard 90.1-2007 

Emission Impact for Adopting Level 3 Over ASHRAE Standard 90.1-2007

2015 2020 2025 2030 2035 2040 2042

Small, Gas-fired, Hot Water

CO2 (metric kilotons/year) (27.78) (106.45) (189.54) (279.64) (382.92) (504.72) (559.13)

NOx (short tons/year) (48.48) (185.78) (330.81) (488.06) (668.31) (880.88) (975.86)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Gas-fired, Steam, All Except 

natural Draft

CO2 (metric kilotons/year) (22.79) (40.27) (40.27) (59.22) (80.94) (106.55) (118.00)

NOx (short tons/year) (39.78) (70.28) (70.28) (103.35) (141.26) (185.97) (205.94)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Gas-fired, Steam, Natural Draft

CO2 (metric kilotons/year) (19.12) (49.24) (69.44) (86.17) (105.32) (127.90) (138.01)

NOx (short tons/year) (33.36) (85.95) (121.19) (150.40) (183.82) (223.23) (240.86)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Oil-fired, Hot Water 

CO2 (metric kilotons/year) (14.37) (58.18) (104.45) (154.63) (212.15) (279.98) (310.29)

NOx (short tons/year) (17.76) (71.90) (129.08) (191.09) (262.16) (345.99) (383.44)

SO2 (short tons/year) (55.75) (225.75) (405.31) (600.01) (823.20) (1086.41) (1204.01)

Small, Oil-fired, Steam

CO2 (metric kilotons/year) (18.72) (70.54) (125.27) (184.61) (252.63) (332.85) (368.69)

NOx (short tons/year) (23.14) (87.17) (154.80) (228.13) (312.19) (411.33) (455.62)

SO2 (short tons/year) (72.65) (273.71) (486.08) (716.34) (980.28) (1291.56) (1430.64)

Large, Gas-fired, Hot Water

CO2 (metric kilotons/year) (12.10) (46.39) (82.62) (121.89) (166.91) (220.01) (243.73)

NOx (short tons/year) (21.12) (80.97) (144.19) (212.74) (291.31) (383.98) (425.38)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Gas-fired, Steam, All Except 

Natural Draft

CO2 (metric kilotons/year) (21.87) (80.45) (142.32) (209.40) (286.30) (376.98) (417.50)

NOx (short tons/year) (38.17) (140.40) (248.39) (365.47) (499.68) (657.95) (728.67)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Gas-fired, Steam, Natural Draft

CO2 (metric kilotons/year) (12.81) (48.57) (61.67) (68.44) (73.09) (74.24) (73.66)

NOx (short tons/year) (22.36) (84.77) (107.64) (119.44) (127.57) (129.57) (128.56)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Oil-fired, Hot Water

CO2 (metric kilotons/year) (9.87) (35.55) (62.67) (92.08) (125.79) (165.54) (183.30)

NOx (short tons/year) (12.20) (43.93) (77.45) (113.79) (155.44) (204.57) (226.52)

SO2 (short tons/year) (38.29) (137.94) (243.18) (357.29) (488.09) (642.34) (711.26)

Large, Oil-fired, Steam 

CO2 (metric kilotons/year) (57.78) (208.14) (366.96) (539.14) (736.51) (969.28) (1,073.28)

NOx (short tons/year) (71.41) (257.21) (453.47) (666.25) (910.15) (1,197.80) (1,326.32)

SO2 (short tons/year) (224.22) (807.66) (1,423.90) (2,092.03) (2,857.89) (3,761.09) (4,164.63)
ASHRAE_90 1_EA_TSD_05-22-09.doc

8-16

Table 8.7.7 Summary of National Emissions Impact for Commercial Boilers from 2012 to 2042 for Adopting Level 4 over 

ASHRAE Standard 90.1-2007 

Emission Impact for Adopting Level 4 Over ASHRAE Standard 90.1-2007*

2015 2020 2025 2030 2035 2040 2042

Small, Gas-fired, Hot Water

CO2 (metric kilotons/year) (43.10) (161.63) (286.84) (422.59) (578.20) (761.71) (843.70)

NOx (short tons/year) (75.22) (282.10) (500.62) (737.55) (1,009.13) (1,329.42) (1,472.52)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Gas-fired, Steam, All Except 

natural Draft

CO2 (metric kilotons/year) (34.80) (61.44) (61.44) (90.33) (123.43) (162.48) (179.92)

NOx (short tons/year) (60.74) (107.24) (107.24) (157.65) (215.43) (283.58) (314.02)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Small, Gas-fired, Steam, Natural Draft

CO2 (metric kilotons/year) na na na na na na na

NOx (short tons/year) na na na na na na na

SO2 (short tons/year) na na na na na na na

Small, Oil-fired, Hot Water 

CO2 (metric kilotons/year) na na na na na na na

NOx (short tons/year) na na na na na na na

SO2 (short tons/year) na na na na na na na

Small, Oil-fired, Steam 

CO2 (metric kilotons/year) na na na na na na na

NOx (short tons/year) na na na na na na na

SO2 (short tons/year) na na na na na na na

Large, Gas-fired, Hot Water

CO2 (metric kilotons/year) (36.64) (134.78) (238.43) (350.82) (479.65) (631.58) (699.46)

NOx (short tons/year) (63.94) (235.23) (416.14) (612.29) (837.13) (1,102.30) (1,220.77)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Gas-fired, Steam, All Except 

Natural Draft

CO2 (metric kilotons/year) (30.98) (113.27) (200.19) (294.43) (402.45) (529.84) (586.76)

NOx (short tons/year) (54.07) (197.69) (349.39) (513.87) (702.40) (924.74) (1,024.08)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Gas-fired, Steam, Natural Draft

CO2 (metric kilotons/year) (20.58) (76.69) (111.46) (141.18) (170.12) (197.00) (207.19)

NOx (short tons/year) (35.92) (133.85) (194.53) (246.40) (296.91) (343.83) (361.61)

SO2 (short tons/year) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Large, Oil-fired, Hot Water

CO2 (metric kilotons/year) na na na na na na na

NOx (short tons/year) na na na na na na na

SO2 (short tons/year) na na na na na na na

Large, Oil-fired, Steam

CO2 (metric kilotons/year) (119.45) (430.27) (758.58) (1,114.52) (1,522.52) (2,003.70) (2,218.68)

NOx (short tons/year) (147.61) (531.71) (937.42) (1,377.28) (1,881.47) (2,476.09) (2,741.76)

SO2 (short tons/year) (463.51) (1,669.58) (2,943.50) (4,324.65) (5,907.82) (7,774.93) (8,609.12)

“na” indicates that the technology did not have an energy efficiency level 4.
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8.8 EFFECTS ON UPSTREAM FUEL-CYCLE EMISSIONS

Fuel-cycle emissions often refer to the emissions associated with the amount of energy 

used in the upstream production and downstream consumption of electricity, including energy 

used at the power plant. However, there are additional energy costs associated with the 

extraction, refining, and transport of fuel oil and the extraction, physical preparatory and 

cleaning processes, and transportation to the point of end use of natural gas. The analysis of 

emissions impacts calculated for this rule used emission coefficients based on the point of use 

and the site energy savings from higher-efficiency equipment. The analysis does a thorough 

accounting of emissions at the point of use, but does not account for upstream emissions (i.e., 

emissions from energy losses during fuel oil and natural gas production). While the site-tosource energy conversion factor of approximately 10 percent was used in the development of 

source energy savings estimates, some fraction of this would occur in the form of larger 

equipment that would likely have more emission controls on them than are seen in commercial 

packaged boilers. A very rough estimate might be that an additional 10 percent impact (typically, 

this will be savings) might result due to impacts on upstream fuel-cycle emissions.

8.9 WETLAND, ENDANGERED AND THREATENED SPECIES, AND CULTURAL 

RESOURCES

DOE’s proposed action is not site-specific, nor would it affect land disturbance or use 

resulting from the installation of commercial boilers in commercial buildings. Therefore, none of 

the proposed possible standard levels is expected to affect the quality of wetlands, or threatened 

or endangered species or their critical habitat. Further, this action is not expected to affect

cultural resources such as historical or archaeological sites.

8.10 ENVIRONMENTAL JUSTICE IMPACTS

Under Executive Order 12898, “Federal Actions to Address Environmental Justice in 

Minority Populations and Low-Income Populations,” 59 FR 7629 (Feb. 16, 1994), DOE is 

required to make achieving environmental justice part of its mission by identifying and 

addressing, as appropriate, disproportionately high and adverse human health or environmental 

effects of its programs, policies, and activities on minority populations and low-income 

populations in the United States. In examining each of the possible energy conservation 

standards for commercial packaged boilers, DOE did not identify any high and adverse human 

health or environmental effects that it believes would disproportionally or negatively impact 

minority or low-income populations. In general, the environmental impacts associated with

adoption of higher-efficiency commercial packaged boiler standards are positive in that they are 

found to result in reduced overall emissions of air pollutants where such boilers are used, with 

correspondingly positive local environmental impacts for all populations.

In terms of standard-setting, DOE is legally mandated to adopt standards at the ASHRAE 

Standard 90.1-2007 efficiency levels, unless more stringent energy conservation standards are 

technologically feasible, economically justified, and would result in significant additional energy 

savings. (42 U.S.C. 6313(a)(6)(A)(ii)) Because of the ANSI/ASHRAE consensus process in 

developing ASHRAE Standard 90.1, the representation of industry groups like the Gas 

Appliance Manufacturers Association (GAMA) in that process, and the opportunity for public 
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comment in that process, DOE believes that there would be no highly negative disproportionate 

impacts on small businesses used by minority or low-income commercial customers resulting 

from adoption of national energy conservation standards at the ASHRAE Standard 90.1-2007 

efficiency levels. Accordingly, DOE's LCC analysis (see TSD Chapter 7) did not include small 

or disadvantaged businesses or populations as a subgroup. If DOE determines that more 

stringent standards are in fact justified, DOE would do an LCC Subgroup analysis to ascertain 

whether there would be impacts on specific populations subgroups, including certain types of 

commercial customers, that would need to be examined in the light of the overall justification 

necessary to adopt more stringent standards. 

8.11 NOISE AND AESTHETICS

Improvements in efficiency of commercial boilers and furnace equipment are expected to 

result from changes in the choice of components and other design features. These changes are 

described in Chapter 5 of this TSD. Efficiency improvements are not expected to change noise 

levels in comparison to equipment in today’s market. Equipment that is currently manufactured 

in the existing market that would meet the proposed standards is no louder than less-efficient 

equipment. Changes to the design to improve the efficiency levels are not anticipated to affect 

the equipment’s aesthetics.
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