Recommendation Opposing Hydronic Heater Standard NSPS, page 1 of 6

Recommendation Opposing Hydronic Heater Standard in Residential Wood Heater NSPS: 

EPA Proposed Certification of Phase 2 Hydronic Heaters yet Obscured Relevant

Efficiency Data for the Phase 2 Central Boiler E-Classic 2300

Prepared by <cleanairfairbanks@gmail.com> 9/28/2013

The 30 percent average thermal efficiency1of a Phase 2 Central Boiler E-Classic 2300, according

to EPA’s 2012 study, compares “poorly with oil and natural gas fired residential systems with 

thermal efficiencies ranging from 86% to 92% and 79% to 90%, respectively (McDonald, 

2009).”

2

Figure 2. The Three Stage HH Unit and Illustration of a Down-Draft Combustion Unit

[Gullett, Wood 2012, p 93]

Table 3. Hydronic Heater Efficiencies [Gullett, Wood 2012, p 16, emphasis added4]

Units Thermal Efficiency (%) Boiler Combustion

Conventional HH RO 

Average 22 NC 74

STDV 5 3.0

Conventional HH RO + Ref 

Average 31 NC 87

STDV 2.2 3.4

Conventional HH WP 

Average 29 NC 82

STDV 1.8 3.2

Three Stage HH/RO Average 30 NC 86

STDV 3.2 1.8

European Pellet/pellets Average 44 86 98

STDV 4.1 3.5 0.16

U.S. Downdraft RO 

Average IM 83 90

STDV 0.71 0.79

NC = Not calculated. IM = Insufficient measurements taken for this calculation
Recommendation Opposing Hydronic Heater Standard NSPS, page 2 of 6

The make and model of the three-stage hydronic heater in Table 3 Gullett, Wood 2012 (above) 

is identified in a presentation by Sidhu and Gullet. Both reports use the same photo. Gullett, 

Wood 2012 on page 9 and Sidhu, Gullett 2011 on page 17. There can be no doubt that the 

heater identified as ”Three Stage HH” in Gullett, Wood 2012 is the EPA Phase 2 qualified 

Central Boiler E-Classic 2300.

Central Boiler E-Classic 2300 Three stage Combustion Process

[Sidhu, Gullett 2011, p 175]

Due to this model’s 30 percent thermal efficiency, where 70 percent of the heat value of the 

fuel is lost, the operator must use a lot more fuel. Table 3 also shows a combustion efficiency of 

86 percent for the same model. 86 percent combustion efficiency means 14 percent of the fuel 

is wasted, much of it being released as unburned wood particles.

It is reasonable to conclude that a hydronic heater having 86 percent combustion efficiency 

together with 30 percent thermal efficiency would have significant amounts of unburned fuel 

going out the chimney that may cause a health risk.

NSPS Policy Relevance:

On July 26, 2013, OMB received from EPA a package of proposed regulations for residential 

wood heaters under the New Source Performance Standards (NSPS) in the Clean Air Act.6 Gill 

Wood and David Cole with EPA submitted the proposed rule.7

In public presentations in since 2012 and earlier, EPA has proposed to certify Phase 2 hydronic 

heaters: “matches EPA Phase 2.”

8

Central Boiler E-Classic 2300 is on EPA’s list of Phase 2

hydronic heaters.

9
Recommendation Opposing Hydronic Heater Standard NSPS, page 3 of 6

EPA Efforts to Obscure:

Gil Wood and other EPA staff with the Office of Air Quality Planning and Standards had full 

knowledge that their own study, published in Gullett, Wood 201210, tested the Central Boiler EClassic 2300. However, the make and model was withheld in the report. The 2012 report also 

fails to reference that the model tested was EPA Phase 2. The photograph on page 9 in the 

report even obscures the “Central Boiler Classic” label on the heater door with a white 

rectangle. Yet, when the image is copied into another document, the white label disappears, 

revealing the manufacturer’s label. Through a separate study by Sidhu, Gullett 201111, we are 

able to identify the device by the coincidence that both reports use the same photo.

We cannot explain the clear effort to mislead the public and agencies in the run-up to public 

release of the first draft regulations for hydronic heaters. While we understand that EPA must 

not release confidential business information, a scientific study must identify the object being 

tested otherwise the study is not reproducible or policy relevant. Make and model and 

photographs of the device are not confidential business information and are not required to be 

redacted under the EPA Phase 2 voluntary agreement.12 The Phase 2 voluntary agreement is an 

off-the-books, quasi-regulatory standard lacking public notice, public or agency review, or any 

oversight given during rulemaking, and lacks statutory enforceability. The Phase 2 voluntary 

agreement is purely a contract of convenience between EPA and an individual manufacturer.

Further, nowhere in the slow-motion lead-in to hydronic heater rulemaking has EPA once 

plainly stated that the proposed rules would “certify” Phase 2 hydronic heaters under NSPS.

Examples:

1) The most recent public update, March 2013, states, “Partnership Program Phase 2 level 

upon promulgation.”

13

2) Feb. 2012 and Dec. 2011 drafts state that the approach for hydronic heaters “matches 

Phase 2 of EPA voluntary program.” 14,15

3) EPA’s March 2011 update to tribes stated, “0.32 lb / mmBTU heat output for outdoor 

HH in 2013 and indoor in 2014.”

16

4) Feb. 2011 update on NSPS regarding hydronic heaters notes, “Include in NSPS.”

17

Agency staff and a few members of the public have been able to see through EPA’s 

bureaucratic language proposing certification of Phase 2 hydronic heaters. However, it is 

neither clear nor plain, we suspect deliberately so.

By its actions and omissions, EPA has hidden vital information relevant to assessing the 

efficiency (or lack of) of Phase 2 hydronic heaters and failed to state the proposed regulations 

would adopt Phase 2 as the certified standard for hydronic heaters. EPA has done nothing but 

impede the public’s ability to connect the dots between a particular Phase 2 heater and the 

wrath of smoke it would reasonably be expected to emit. Of greatest concern is that EPA has 

sought to conceal the connection between the Phase 2 device and its 30 thermal efficiency at 

the same time as EPA is recommending certification of these devices. 
Recommendation Opposing Hydronic Heater Standard NSPS, page 4 of 6

Conclusions:

In its own Gullett, Wood 2012 report, EPA concludes that the tested three-stage hydronic 

heater has only 30 percent thermal efficiency. The policy relevance is that such a highly 

inefficient wood heating device would be expected to produce significant noxious emissions. 

The model tested was clearly EPA Phase 2. Yet, because EPA obscured the make and model, 

EPA is unable to relate its own test of a Phase 2 heater to its current proposal to include Phase 

2 in the certified residential wood heater standard.

We ask that OMB ensure that Phase 2 not be included in the proposed rule that goes forward 

to public comment.

EPA’s Office of Air Quality Planning and Standards is responsible for setting standards to protect 

public health. Obscuring the manufacturer’s label, failing to disclose the model, omitting that 

the device tested was EPA Phase 2, then packaging a draft rule that inarticulately but 

specifically certifies Phase 2 under the NSPS is deceptive and injurious.

By law, EPA is bound to pursue a standard that “shall include a category of sources in such list if 

in his judgment it causes, or contributes significantly to, air pollution which may reasonably be 

anticipated to endanger public health or welfare.”18 The NSPS was enacted in 1988 and has not 

been updated to include a standard to regulate the significant harm and air pollution from

hydronic heaters. EPA proposes a remedy, but the Phase 2 standard, based on incomplete 

information with clear evidence to the contrary, is malfeasance and harmful to the public 

interest. The cost to public health from Phase 2 hydronic heaters far exceeds any benefit.

We strenuously object to EPA’s lack of transparency. The highest standards of integrity must 

apply when the issue is a matter of life and safety. EPA appears to have pursued a 

predetermined goal of certifying Phase 2 regardless of the evidence of harm and inefficiency. 

Communities, neighbors, and purchasers deserve better from those whose job it is to set the 

standards that protect lives and safety.

Sources:

Brian Gullett, Gil Wood, et al, June 2012, Environmental, Energy Market, and Health 

Characterization of Wood-Fired Hydronic Heater Technologies, Report 12-15, Executive 

Summary, US EPA, Office of Research and Development and Office of Air Quality Planning and 

Standards for New York State Energy Research and Development Authority.

Executive Summary - Environmental, Energy Market, and Health Characterization of WoodFired Hydronic Heater Technologies – NYSERDA 12-15

Full Report - Environmental, Energy Market, and Health Characterization of Wood-Fired 

Hydronic Heater Technologies – NYSERDA 12-15
Recommendation Opposing Hydronic Heater Standard NSPS, page 5 of 6

Sukh Sidhu, Brian Gullett, et al, March 2011, Toxic Air Emissions from Burning Wood and 

Agricultural Plastics–A Cone Calorimeter Study, Great Lakes Commission webinar presentation. 

Presentation: http://www.glc.org/glad/projects/sidhu08/GLCWebinar110331-Sidhu.pdf

Webinar Series: http://glc.org/glad/meetings/webinar/

EPA Regulatory Development and Retrospective Review Tracker for Residential Wood Heater 

NSPS: http://yosemite.epa.gov/opei/rulegate.nsf/byRIN/2060-AP93

OMB rulemaking page on Residential Wood Heater NSPS:

http://www.reginfo.gov/public/do/eAgendaViewRule?pubId=201304&RIN=2060-AP93

For Green Heat webpage review of OMB rulemaking process:

http://forgreenheat.blogspot.com/2013/08/explanation-of-omb-review-of-nsps.html

EPA list of Phase 2 qualified hydronic heaters (includes Central Boiler E-Classic 2300):

http://www.epa.gov/burnwise/owhhlist.html (last accessed 9/28/2013)

EPA draft update Residential Wood Heaters NSPS 3/22/2013:

http://www.epa.gov/burnwise/pdfs/NSPSDraftProposal32213.pdf

EPA public outreach on draft proposed rule Residential Wood Heaters NSPS, Webinar 2/9/2012:

http://www.epa.gov/burnwise/pdfs/20120209NSPSpresentation.pdf

EPA status of draft proposed rule Residential Wood Heaters NSPS 12/8/2011:

http://www.epa.gov/burnwise/pdfs/20111208nspspresentation.pdf

EPA draft revisions tribal consultation call Residential Wood Heaters NSPS 3/29/2011, p 16. 

http://www.epa.gov/air/tribal/pdfs/3-29-

11TribalConsultation%20Call__Wood%20HeatersNSPS.pdf

EPA draft options Residential Wood Heaters NSPS 2/15/2011:

http://www.epa.gov/burnwise/pdfs/20110215NSPSDraftOptionsTable.pdf

EPA revised draft review document Residential Wood Heaters NSPS 5/25/2010:

http://www.epa.gov/burnwise/pdfs/20091230draftreviewofnspssubpartAAA.pdf

EPA Hydronic Heater Program Phase 2 Partnership Agreement between EPA Office of Air 

Quality Planning and Standards and individual manufacturers: 

http://www.epa.gov/burnwise/pdfs/owhhphase2agreement.pdf

40 CFR Part 2 (see subpart B for Confidential Business Information) 

http://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol1/xml/CFR-2012-title40-vol1-part2.xml

Clean Air Act, New Source Performance Standards 42 USC § 7411
Recommendation Opposing Hydronic Heater Standard NSPS, page 6 of 6

Definitions:

Thermal efficiency is a measure of the effectiveness of the heat exchanger of the boiler. It 

measures the ability of the exchanger to transfer heat from the combustion process to the 

water or steam in the boiler. Boiler Efficiency Guide - Cleaver-Brooks p 8

Combustion efficiency is an indication of the burner’s ability to burn fuel. The amount of 

unburned fuel and excess air in the exhaust are used to assess a burner’s combustion efficiency. 

Combustion efficiency is not the same for all fuels and, generally, gaseous and liquid fuels burn 

more efficiently than solid fuels. Boiler Efficiency Guide - Cleaver-Brooks p 8

 

1

Brian Gullett, Gil Wood, et al, June 2012, Environmental, Energy Market, and Health Characterization of WoodFired Hydronic Heater Technologies, Report 12-15, Executive Summary, US EPA, Office of Research and 

Development and Office of Air Quality Planning and Standards for NYSERDA, p 16.

2

Gullett, Wood, 2012, p 32.

3

Gullett, Wood, 2012, p 9.

4

Gullett, Wood, 2012, p 16.

5

Sukh Sidhu, Brian Gullett, et al, March 2011, Toxic Air Emissions from Burning Wood and Agricultural Plastics–A 

Cone Calorimeter Study, Great Lakes Commission webinar presentation, p 17.

6

EPA Regulatory Development and Retrospective Review Tracker for Residential Wood Heater NSPS website.

7

OMB rulemaking webpage on Residential Wood Heater NSPS.

8

EPA draft rule Residential Wood Heaters NSPS, Webinar 2/9/2012, p 20.

9

EPA list of Phase 2 qualified hydronic heaters webpage.

10 Gullett, Wood, 2012.

11 Sidhu, Gullett, 2011.

12 EPA Hydronic Heater Program Phase 2 Partnership Agreement, p 6.

13 EPA draft update Residential Wood Heaters NSPS 3/22/2013, p 5.

14 EPA public outreach on draft proposed rule Residential Wood Heaters NSPS, Webinar 2/9/2012, p 20.

15 EPA draft proposal Residential Wood Heaters NSPS 12/8/2011, p 8.

16 EPA draft revisions tribal consultation call Residential Wood Heaters NSPS 3/29/2011, p 16.

17 EPA draft options Residential Wood Heaters NSPS 2/15/2011, p 1.

18 Clean Air Act, New Source Performance Standards 42 USC § 7411(b)(1)(A).