December 21, 2006

GAMA/DOE Meeting - Furnace and Boiler Energy Conservation

Standards Rulemaking

December 14, 2006

Note: GAMA requested the meeting and posed several questions to the Department

in an email received on December 1, 2006. (A hardcopy of the GAMA email

along with material GAMA presented at the meeting are included herewith.)

Attendees:

Mohammed Khan, DOE/BT

Michael McCabe, DOE/BT

Ron Lewis, DOE/BT

Francine Pinto, DOE/GC

Chris Calamita, DOE/GC

Mike Rivest, Navigant Consulting

Laura Van Wie McGrory, LBNL

Alan Kessler, Rheem

Gloria Pumpuni, GAMA

Tim Waterman, Carrier

Frank Stanonik, GAMA

On phone:

Mark Friedrichs, DOE/PI

Alex Lekov, LBNL

Jim McMahon, LBNL

Ashley Abbott, Navigant Consulting

Graham Stevens, Navigant Consulting

Dick Topping, RF Topping, LLC on behalf of GAMA

Meeting Summary

Mohammed Khan stated that he would first address the four questions posed by GAMA

in their December 1, 2006 email to the Department of Energy (DOE), and then would

discuss any additional questions or issues. The General Counsel's office noted that this

meeting will be summarized in a memo and entered into the rulemaking docket.

Numbers 1-4 below summarize GAMA's four questions, DOE's response , and any

discussion of these issues that took place.

1) Question: What is the breakdown for material costs in your analysis on weatherized

furnaces?

DOE response: The breakdown of material costs-in terms of material, labor,

transportation, and overhead-is provided in Table E. 1.3 of Appendix E of the

Technical Support Document (TSD) for the furnace and boiler notice of proposed

rulemaking (NOPR). The table also includes the incremental manufacturing cost and

EE-RM/STD-01-350 COMMENT 146

December 21, 2006 

GAMAIDOE Meeting - Furnace and Boiler Energy Conservation 

Standards Rulemaking 

December 14, 2006 

#146 

Note: GAMA requested the meeting and posed several questions to the Department 

in an email received on December 1, 2006. (A hardcopy of the GAMA email 

along with material GAMA presented at the meeting are included herewith.) 

Attendees: 

Mohammed Khan, DOE/BT 

Michael McCabe, DOE/BT 

Ron Lewis, DOEIBT 

Francine Pinto, DOE/GC 

Chris Calamita, DOE/GC 

Mike Rivest, Navigant Consulting 

Laura Van Wie McGrory, LBNL 

Alan Kessler, Rheem 

Gloria Pumpuni, GAMA 

Tim Waterman, Carrier 

Frank Stanonik, GAMA 

On phone: 

Mark Friedrichs, DOE/PI 

Alex Lekov, LBNL 

Jim McMahon, LBNL 

Ashley Abbott, Navigant Consulting 

Graham Stevens, N avigant Consulting 

Dick Topping, RF Topping, LLC on behalf of GAMA 

Meeting Summary 

Mohammed Khan stated that he would first address the four questions posed by GAMA 

in their December 1,2006 email to the Department of Energy (DOE), and then would 

discuss any additional questions or issues. The General Counsel's office noted that this 

meeting will be summarized in a memo and entered into the rulemaking docket. 

Numbers 1-4 below summarize GAMA's four questions, DOE's response, and any 

discussion of these issues that took place. 

1) Question: What is the breakdown for material costs in your analysis on weatherized 

furnaces? 

DOE response: The breakdown of material costs-in terms of material, labor, 

transportation, and overhead-is provided in Table E.l.3 of Appendix E of the 

Technical Support Document (TSD) for the furnace and boiler notice of proposed 

rulemaking (NOPR). The table also includes the incremental manufacturing cost and 
December 21, 2006

the technological improvements that were made to increase the AFUE of the baseline

unit.

2) Question: Why are the material costs for the baseline weatherized furnaces more than

double that of the baseline model for non-weatherized furnaces?

DOE Response: The material costs for the baseline weatherized furnaces include the part

costs associated with the 3-ton air conditioner unit, which is usually packaged with

the furnace. These costs are also found in Table E.1.3 of Appendix E of the NOPR

TSD.

Discussion:

• GAMA asked what SEER (e.g., 10) DOE assumed on the cooling side. GAMA

pointed out that a 13-SEER AC unit was probably more representative since the

central AC efficiency standards were increased in January 2006. LBNL

responded that DOE did not look at air conditioning efficiency ratings in any

detail. DOE was only concerned with the incremental costs that affect the annual

fuel utilization efficiency (AFUE) of the furnace.

• DOE noted that it assumed the same material costs for the air conditioner

throughout the range of AFUE levels, which allowed DOE to capture the potential

effects on the analysis if DOE changed the design options for improving the

efficiency of the furnace. The weatherized gas furnace unit is described section

6.4.1.1, "Teardown Approach," of Chapter 6 of the NOPR TSD. GAMA said

that, from a percentage standpoint, the dollar difference would be the same. If the

costs are constant, DOE just needs to capture the incremental cost for improving

the furnace.

3) Question: Does the analysis on weatherized furnaces include an all-stainless-steel heat

exchanger design?

DOE response: No. DOE assumed manufacturers would use aluminized steel for the

heat exchangers of weatherized gas furnaces. This aluminized steel is the same

material used for the higher-volume non-weatherized gas furnaces and, DOE

assumed, it would allow manufacturers to take advantage of high-volume material

pricing. DOE assumed the use of this aluminized steel for all weatherized gas

furnace heat exchanger materials regardless of equipment efficiency as shown in

Table E.1.3 of Appendix E of the NOPR TSD.

Discussion:

• DOE noted that the only improvement it considered for the development of the

cost-efficiency curves was the increase in heat exchanger area (no other changes

in the heat exchanger including heat exchanger material).

• GAMA asked what heat exchanger sizes DOE assumed for each AFUE level and

noted that manufacturers have to change a lot of materials and add other

components such as condensate drains that were not considered in the analysis

when furnaces reach condensing levels. Specifically, GAMA asked how much

more material DOE assumed would have to be added to get up to 83% AFUE?

EE-RM/STD-01-350 COMMENT 146

December 21, 2006 #146 

the technological improvements that were made to increase the AFUE of the baseline 

unit. 

2) Question: Why are the material costs for the baseline weatherized furnaces more than 

double that of the baseline model for non-weatherized furnaces? 

DOE Response: The material costs for the baseline weatherized furnaces include the part 

costs associated with the 3-ton air conditioner unit, which is usually packaged with 

the furnace. These costs are also found in Table E.1.3 of Appendix E of the NOPR 

TSD. 

Discussion: 

• GAMA asked what SEER (e.g., 10) DOE assumed on the cooling side. GAMA 

pointed out that a 13-SEER AC unit was probably more representative since the 

central AC efficiency standards were increased in January 2006. LBNL 

responded that DOE did not look at air conditioning efficiency ratings in any 

detail. DOE was only concerned with the incremental costs that affect the annual 

fuel utilization efficiency (AFUE) of the furnace. 

• DOE noted that it assumed the same material costs for the air conditioner 

throughout the range of AFUE levels, which allowed DOE to capture the potential 

effects on the analysis if DOE changed the design options for improving the 

efficiency of the furnace. The weatherized gas furnace unit is described section 

6.4.1.1, "Teardown Approach," of Chapter 6 of the NOPR TSD. GAMA said 

that, from a percentage standpoint, the dollar difference would be the same. If the 

costs are constant, DOE just needs to capture the incremental cost for improving 

the furnace. 

3) Question: Does the analysis on weatherized furnaces include an all-stainless-steel heat 

exchanger design? 

DOE response: No. DOE assumed manufacturers would use aluminized steel for the 

heat exchangers of weatherized gas furnaces. This aluminized steel is the same 

material used for the higher-volume non-weatherized gas furnaces and, DOE 

assumed, it would allow manufacturers to take advantage of high-volume material 

pricing. DOE assumed the use of this aluminized steel for all weatherized gas 

furnace heat exchanger materials regardless of equipment efficiency as shown in 

Table E.1.3 of Appendix E of the NOPR TSD. 

Discussion: 

• DOE noted that the only improvement it considered for the development of the 

cost-efficiency curves was the increase in heat exchanger area (no other changes 

in the heat exchanger including heat exchanger material). 

• GAMA asked what heat exchanger sizes DOE assumed for each AFUE level and 

noted that manufacturers have to change a lot of materials and add other 

components such as condensate drains that were not considered in the analysis 

when furnaces reach condensing levels. Specifically, GAMA asked how much 

more material DOE assumed would have to be added to get up to 83% AFUE? 
December 21, 2006

GAMA stated that some manufacturers believe that the improvement in AFUE

with increased heat exchanger area is not a linear relationship, as they believe

DOE assumed in the engineering analysis. In their opinion, it takes a lot more

material to get the incremental benefit of higher efficiency.

® Navigant said that the TSD does not report the specific amount of material added

to the heat exchangers to reach higher AFUE levels, but it noted that the analysis

assumed relatively small incremental changes in heat exchanger area going from

78% to 83% AFUE. (The analysis shows incremental material costs for each

AFUE increment.)

® DOE stated that if GAMA had information to support a different assumption then

GAMA should provide DOE through written comments information about the

incremental material costs associated with attaining these higher efficiency levels

over the baseline, which account for the increase in heat exchanger area. GAMA

responded that they would try to supply this information in their comment.

4) Question: What are differences in characteristics of the insulation material used in the

teardown unit versus the improved insulation material that DOE considered?

DOE response: DOE did not consider different insulation material as a design option for

weatherized gas furnaces. DOE initially investigated the effects of a thicker amount

of insulation on AFUE in weatherized gas furnaces (the addition of 1/2 inch of

insulation over the baseline). Although DOE analyzed this thicker insulation as a

possible design option early on in the analysis (ANOPR), it did not include it in the

NOPR analysis due to its small impact on the furnace efficiency. DOE only

considered increased heat exchanger size in developing the cost-efficiency curves as

shown in Figure 6.4.4 of Chapter 6 of the NOPR TSD.

Discussion: GAMA agreed that manufacturers cannot do much with insulation; it does

not have a great impact on AFUE. GAMA stated that it seems that DOE came to the

same conclusion, and GAMA does not need to deal with this further in its written

comments.

OTHER ISSUES

5) Effects of Going to Condensing Levels on Durability, Performance, and Safety.

GAMA described its major concern: GAMA's members would have to make significant

changes to their current products to be able to consistently manufacture an 83-percent

AFUE outdoor furnace that will be durable, perform as the customer expects, and-most

importantly-won't corrode to the extent that it becomes a safety hazard. GAMA

presented two graphs as illustrations:

• Graph 1: Category Determination for Natural Gas Furnaces. GAMA explained that

furnace categorization defines the vents needed dependent upon product class and is a

well established chart and practice used in the safety standards for gas furnaces. The

chart shows the net flue temperature graphed against the percentage of carbon dioxide

in the flue products. The line going from a furnace that condenses occasionally to

one that condenses all the time is just below 84% steady-state efficiency (SSE).

GAMA stated that AFUE is always less than the SSE for weatherized gas furnaces,

and that the industry will have to develop weatherized gas furnaces that have a SSE

EE-RM/STD-01-350 COMMENT 146

December 21, 2006 #146 

GAMA stated that some manufacturers believe that the improvement in AFUE 

with increased heat exchanger area is not a linear relationship, as they believe 

DOE assumed in the engineering analysis. In their opinion, it takes a lot more 

material to get the incremental benefit of higher efficiency. 

• Navigant said that the TSD does not report the specific amount of material added 

to the heat exchangers to reach higher AFUE levels, but it noted that the analysis 

assumed relatively small incremental changes in heat exchanger area going from 

78% to 83% AFUE. (The analysis shows incremental material costs for each 

AFUE increment.) 

• DOE stated that if GAMA had information to support a different assumption then 

GAMA should provide DOE through written comments information about the 

incremental material costs associated with attaining these higher efficiency levels 

over the baseline, which account for the increase in heat exchanger area. GAMA 

responded that they would try to supply this information in their comment. 

4) Question: What are differences in characteristics of the insulation material used in the 

teardown unit versus the improved insulation material that DOE considered? 

DOE response: DOE did not consider different insulation material as a design option for 

weatherized gas furnaces. DOE initially investigated the effects of a thicker amount 

of insulation on AFUE in weatherized gas furnaces (the addition of 1;2 inch of 

insulation over the baseline). Although DOE analyzed this thicker insulation as a 

possible design option early on in the analysis (ANOPR), it did not include it in the 

NOPR analysis due to its small impact on the furnace efficiency. DOE only 

considered increased heat exchanger size in developing the cost-efficiency curves as 

shown in Figure 6.4.4 of Chapter 6 of the NOPR TSD. 

Discussion: GAMA agreed that manufacturers cannot do much with insulation; it does 

not have a great impact on AFUE. GAMA stated that it seems that DOE came to the 

same conclusion, and GAMA does not need to deal with this further in its written 

comments. 

OTHER ISSUES 

5) Effects of Going to Condensing Levels on Durability, Performance, and Safety. 

GAMA described its major concern: GAMA's members would have to make significant 

changes to their current products to be able to consistently manufacture an 83-percent 

AFUE outdoor furnace that will be durable, perform as the customer expects, and-most 

importantly-won't corrode to the extent that it becomes a safety hazard. GAMA 

presented two graphs as illustrations: 

• Graph 1: Category Determinationfor Natural Gas Furnaces. GAMA explained that 

furnace categorization defines the vents needed dependent upon product class and is a 

well established chart and practice used in the safety standards for gas furnaces. The 

chart shows the net flue temperature graphed against the percentage of carbon dioxide 

in the flue products. The line going from a furnace that condenses occasionally to 

one that condenses all the time is just below 84% steady-state efficiency (SSE). 

GAMA stated that AFUE is always less than the SSE for weatherized gas furnaces, 

and that the industry will have to develop weatherized gas furnaces that have a SSE 
December 21, 2006

of 84% or more in order to meet an 83 -percent AFUE standard. GAMA further stated

that using the furnace categorization graphs, these types of products would definitely

be in the condensing region, which would require Category II or Category IV

materials.

Graph 2: Weatherized Furnace Flue-Gas-Bearing Component Surface Temperature

vs. Time. The graph shows the surface temperature of an interior component of a

weatherized gas furnace at different efficiencies (80%, 81.5%, and 83% AFUE).

GAMA stated that the graph shows that for an 80-percent AFUE, the temperature of

the collector box surface gets above the dew point in about 2 .5 minutes. GAMA

further stated that at 81 . 5-percent AFUE, the collector box surface temperature

exceeds the dew point when the burner is turning off (approximately at the DOE

burner on time of 3.87 minutes), and at 83-percent AFUE, the collector box surface

temperature never exceeds the dew point temperature.

GAMA noted that these tests were done at 70 degrees (room temperature). In real life,

the units are typically located outdoors and are using outdoor air. In addition, some units

may have an economizer or fresh air intake damper (which introduces outside air into

conditioned air stream), which could further cause additional condensation problems.

GAMA stated that all of those situations further push the unit towards condensing

operation, so there will be surfaces (flue-gas conveying and other surfaces) that

potentially never dry out during the burner-on cycle at the higher efficiency levels.

DOE asked if Category II and Category IV heat exchangers could be manufactured with

aluminized steel. One of the manufacturer representatives replied that is was possible to

make the primary heat exchanger with aluminized steel, but the condensate drain would

have to be 29-4C ("29-4C" is a classification of stainless steel designed for extreme

resistance to chloride ion pitting, crevice corrosion and stress corrosion cracking.)

DOE further asked what is the limit in terms of SSE and AFUE on using products which

utilize aluminized steel. Further, what design changes would be needed to achieve these

types of SSE and AFUE levels (condensing region). Lastly, what would be the

associated cost (incremental) associated with attaining these levels?

GAMA responded that an 83% AFUE standard would force manufacturers to design

products as if they were condensing models, i.e., for 90% AFUE, and that this would

assume the use of stainless steel and the associated material costs. In order for GAMA's

manufacturers to feel comfortable selling products in the 83-percent AFUE range, which

is close to the condensing region, GAMA stated that the manufacturing cost would

increase due to higher costs for material changes and perhaps an increase in the amount

of material needed for the heat exchanger.

GAMA further noted that, when the categories shown in Graph 1 were created, the

industry expected to have units falling into categories I and IV (categories II and III were

considered to be unsafe due to insufficient materials available to handle the condensing

region). GAMA stated that 81.4% AFUE is the maximum efficiency found in its product

catalogues for weatherized cabinets. DOE asked whether, with today's knowledge and

EE-RM/STD-01-350 COMMENT 146

December 21, 2006 #146 

of 84% or more in order to meet an 83-percent AFUE standard. GAMA further stated 

that using the furnace categorization graphs, these types of products would definitely 

be in the condensing region, which would require Category II or Category IV 

materials. 

• Graph 2: Weatherized Furnace Flue-Gas-Bearing Component Suiface Temperature 

vs. Time. The graph shows the surface temperature of an interior component of a 

weatherized gas furnace at different efficiencies (80%, 81.5%, and 83% AFUE). 

GAMA stated that the graph shows that for an 80-percent AFUE, the temperature of 

the collector box surface gets above the dew point in about 2.5 minutes. GAMA 

further stated that at 81.5-percent AFUE, the collector box surface temperature 

exceeds the dew point when the burner is turning off (approximately at the DOE 

burner on time of 3 .87 minutes), and at 83-percent AFUE, the collector box surface 

temperature never exceeds the dew point temperature. 

GAMA noted that these tests were done at 70 degrees (room temperature). In real life, 

the units are typically located outdoors and are using outdoor air. In addition, some units 

may have an economizer or fresh air intake damper (which introduces outside air into 

conditioned air stream), which could further cause additional condensation problems. 

GAMA stated that all of those situations further push the unit towards condensing 

operation, so there will be surfaces (flue-gas conveying and other surfaces) that 

potentially never dry out during the burner-on cycle at the higher efficiency levels. 

DOE asked if Category II and Category IV heat exchangers could be manufactured with 

aluminized steel. One of the manufacturer representatives replied that is was possible to 

make the primary heat exchanger with aluminized steel, but the condensate drain would 

have to be 29-4C ("29-4C" is a classification of stainless steel designed for extreme 

resistance to chloride ion pitting, crevice corrosion and stress corrosion cracking.) 

DOE further asked what is the limit in terms of SSE and AFUE on using products which 

utilize aluminized steel. Further, what design changes would be needed to achieve these 

types of SSE and AFUE levels (condensing region). Lastly, what would be the 

associated cost (incremental) associated with attaining these levels? 

GAMA responded that an 83% AFUE standard would force manufacturers to design 

products as if they were condensing models, i.e., for 90% AFUE, and that this would 

assume the use of stainless steel and the associated material costs. In order for GAMA's 

manufacturers to feel comfortable selling products in the 83-percent AFUE range, which 

is close to the condensing region, GAMA stated that the manufacturing cost would 

increase due to higher costs for material changes and perhaps an increase in the amount 

of material needed for the heat exchanger. 

GAMA further noted that, when the categories shown in Graph 1 were created, the 

industry expected to have units falling into categories I and IV (categories II and III were 

considered to be unsafe due to insufficient materials available to handle the condensing 

region). GAMA stated that 81.4% AFUE is the maximum efficiency found in its product 

catalogues for weatherized cabinets. DOE asked whether, with today's knowledge and 
December 21, 2006

skills, the categories might be created differently. GAMA said no, because the laws of

physics and chemistry have not changed. GAMA noted that, in the 1980s, some

manufacturers tried materials they thought could handle condensing (e.g., 300 and 400

series stainless steels), but had to recall the products because of material problems.

GAMA added that specialize materials, such as high-grade stainless steel (29-4C) has

proved to work in this application.

GAMA stated that today, manufacturers have a better understanding of what materials

would need to be used for condensing weatherized gas furnaces. However, none of the

manufacturers currently offer these types of products.

Regarding Graph 2, DOE asked about the effects of relative humidity. GAMA responded

that, while there is a one-to-one relationship for the return air (if you drop the return air

temperature by 15 degrees, the flue gas drops by 15 degrees), this is not the case for

combustion air which is entirely outdoor air. There could be some relatively humidity

effect..

6) Furnaces Used in Commercial Settings. GAMA noted that some furnaces are

combined with ACs and end up servicing a small business , rather than a home. In those

situations, it is not uncommon for the users to add an economizer , which mixes outdoor

air with conditioned air. GAMA described three types of weatherized furnace

applications:

a) Residential outdoor unit, with all ducting under a crawl space (typically SE USA)

b) Residential rooftop (typically SW USA)

c) Rooftop commercial application. (throughout USA and Canada)

GAMA noted that a specific problem with condensing furnaces is the question of what to

do with the condensate (and pointed out that none of those costs are factored into DOE's

analysis). GAMA stated that potential installation costs should include heated drains to

ensure reliable disposal of condensate.

DOE asked if GAMA considers the actual typical cycle times of furnaces as they are

installed in the field, since these must be longer than 3.7 minutes. GAMA noted that

there are, in fact, a lot of short cycles (e.g., on warm days, and with oversized units).

Navigant noted that with 83% AFUE furnaces (which never get above the dew point) a

lot will depend on the cycle time. GAMA reiterated that 81.4% AFUE is the highest

efficiency they have seen. GAMA speculated that the reason for this is that some

manufacturers tried higher levels and they didn't work. GAMA further noted that

manufacturers cannot design a family of products at the minimum efficiency standard;

they have to account for variability and have an adequate window for compliance.

GAMA stated that the cost increases significantly when there is such a small window

between the maximum level and the minimum standard.

GAMA stated that, to avoid problems, the wet time during a burner on cycle should be

kept under 3 minutes.

EE-RM/STD-01-350 COMMENT 146

December 21, 2006 #146 

skills, the categories might be created differently. GAMA said no, because the laws of 

physics and chemistry have not changed. GAMA noted that, in the 1980s, some 

manufacturers tried materials they thought could handle condensing (e.g., 300 and 400 

series stainless steels), but had to recall the products because of material problems. 

GAMA added that specialize materials, such as high-grade stainless steel (29-4C) has 

proved to work in this application. 

GAMA stated that today, manufacturers have a better understanding of what materials 

would need to be used for condensing weatherized gas furnaces. However, none of the 

manufacturers currently offer these types of products. 

Regarding Graph 2, DOE asked about the effects of relative humidity. GAMA responded 

that, while there is a one-to-one relationship for the return air (if you drop the return air 

temperature by 15 degrees, the flue gas drops by 15 degrees), this is not the case for 

combustion air which is entirely outdoor air. There could be some relatively humidity 

effect.. 

6) Furnaces Used in Commercial Settings. GAMA noted that some furnaces are 

combined with ACs and end up servicing a small business, rather than a home. In those 

situations, it is not uncommon for the users to add an economizer, which mixes outdoor 

air with conditioned air. GAMA described three types of weatherized furnace 

applications: 

a) Residential outdoor unit, with all ducting under a crawl space (typically SE USA) 

b) Residential rooftop (typically SW USA) 

c) Rooftop commercial application. (throughout USA and Canada) 

GAMA noted that a specific problem with condensing furnaces is the question of what to 

do with the condensate (and pointed out that none of those costs are factored into DOE's 

analysis). GAMA stated that potential installation costs should include heated drains to 

ensure reliable disposal of condensate. 

DOE asked ifGAMA considers the actual typical cycle times of furnaces as they are 

installed in the field, since these must be longer than 3.7 minutes. GAMA noted that 

there are, in fact, a lot of short cycles (e.g., on warm days, and with oversized units). 

Navigant noted that with 83% AFUE furnaces (which never get above the dew point) a 

lot will depend on the cycle time. GAMA reiterated that 81.4% AFUE is the highest 

efficiency they have seen. GAMA speculated that the reason for this is that some 

manufacturers tried higher levels and they didn't work. GAMA further noted that 

manufacturers cannot design a family of products at the minimum efficiency standard; 

they have to account for variability and have an adequate window for compliance. 

GAMA stated that the cost increases significantly when there is such a small window 

between the maximum level and the minimum standard. 

GAMA stated that, to avoid problems, the wet time during a burner on cycle should be 

kept under 3 minutes. 
December 21, 2006

7) Potential for Controls to Mitigate Corrosion. DOE asked if GAMA has considered

controls that would enforce an extended cycle time, to guarantee that condensate would

dry up. GAMA identified several problems with this idea: 1) This could cause comfort

issues, such as wide temperature swings; 2) such controls would be hard to reconcile with

the test procedure, since they would extend the burner on-time and thus consume more

energy; 3) the condensate does not always dry out, even after 10 minutes; and 4) some

codes require fixed fresh air, so there is not always a choice in the matter.

8) Condensate Issues. DOE brought up the possibility of the need for provisions to expel

condensate from furnaces. GAMA noted that there are internal traps in the units

themselves, but pointed out that the condensate could freeze in the unit if the furnace

temperature is set back (e.g., while users are on vacation or during night setback).

GAMA also pointed out that it would be unacceptable to have condensate dripping out of

units and creating potential hazards (e.g., pools of condensate, icicles).

9) Economizers: GAMA stated that more people are using economizers because of

indoor air quality issues. DOE stated that GAMA should include any available data on

how and where economizers are used in its comments.

10) DOE's Assumptions about Model Series: GAMA noted that DOE apparently

assumed that annual production of a model series for weatherized furnaces is 100,000

units. However, GAMA's directory identifies nine manufacturers of outdoor units. The

bigger ones have 3-6 model series. So, GAMA estimates that the annual production of a

model series is closer to 10,000. GAMA expressed concern that DOE's overestimation

of how many units an individual manufacturers sells could affect the analysis, since the

economics of recovering costs is off by a factor of 10.

Navigant agreed that it is important to get the numbers right, but pointed out that, in the

manufacturer impact analysis the actual sales volume by manufacturer were used to

calculate the manufacturer impacts and were provided through the manufacturer

interviews. Only about 4% of the sales price is due to depreciation (50% is material), so

there would be less of an impact with sales volume per manufacturer in the engineering,

as further detailed in Chapter 6 of the FB NOPR TSD.

ACTION ITEMS:

• GAMA will send electronic copies of their handouts to Mohammed Khan.

• DOE will circulate the meeting minutes to GAMA for approval before entering them

into the docket.

EE-RM/STD-01-350 COMMENT 146

December 21, 2006 #146 

7) Potential for Controls to Mitigate Corrosion. DOE asked if GAMA has considered 

controls that would enforce an extended cycle time, to guarantee that condensate would 

dry up. GAMA identified several problems with this idea: 1) This could cause comfort 

issues, such as wide temperature swings; 2) such controls would be hard to reconcile with 

the test procedure, since they would extend the burner on-time and thus consume more 

energy; 3) the condensate does not always dry out, even after 10 minutes; and 4) some 

codes require fixed fresh air, so there is not always a choice in the matter. 

8) Condensate Issues. DOE brought up the possibility of the need for provisions to expel 

condensate from furnaces. GAMA noted that there are internal traps in the units 

themselves, but pointed out that the condensate could freeze in the unit if the furnace 

temperature is set back (e.g., while users are on vacation or during night setback). 

GAMA also pointed out that it would be unacceptable to have condensate dripping out of 

units and creating potential hazards (e.g., pools of condensate, icicles). 

9) Economizers: GAMA stated that more people are using economizers because of 

indoor air quality issues. DOE stated that GAMA should include any available data on 

how and where economizers are used in its comments. 

10) DOE's Assumptions about Model Series: GAMA noted that DOE apparently 

assumed that annual production of a model series for weatherized furnaces is 100,000 

units. However, GAMA's directory identifies nine manufacturers of outdoor units. The 

bigger ones have 3-6 model series. So, GAMA estimates that the annual production of a 

model series is closer to 10,000. GAMA expressed concern that DOE's overestimation 

of how many units an individual manufacturers sells could affect the analysis, since the 

economics of recovering costs is offby a factor of 10. 

N avigant agreed that it is important to get the numbers right, but pointed out that, in the 

manufacturer impact analysis the actual sales volume by manufacturer were used to 

calculate the manufacturer impacts and were provided through the manufacturer 

interviews. Only about 4% of the sales price is due to depreciation (50% is material), so 

there would be less of an impact with sales volume per manufacturer in the engineering, 

as further detailed in Chapter 6 of the FB NOPR TSD. 

ACTION ITEMS: 

• GAMA will send electronic copies of their handouts to Mohammed Khan. 

• DOE will circulate the meeting minutes to GAMA for approval before entering them 

into the docket.