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 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 ofthe GAMA email along with material GAMApresented at the meeting areincluded herewith.)

Attendees: Mohammed Khan, DOE/BT Michael McCabe, DOE/BT RonLewis, DOEIBT Francine Pinto, DOE/GC Chris Calamita, DOE/GC Mike Rivest, Navigant Consulting Laura VanWie McGrory, LBNL Alan Kessler, Rheem Gloria Pumpuni, GAMA TimWaterman, Carrier Frank Stanonik, GAMA



### Onphone: Mark Friedrichs, DOE/PI Alex Lekov, LBNL Jim McMahon, LBNL Ashley Abbott, Navigant Consulting Graham Stevens, Navigant Consulting Dick Topping, RF Topping, LLC on behalfofGAMA
Meeting Summary

Mohammed Khan statedthat he would first address the four questions posedby GAMA in their December 1,2006 email to the Department ofEnergy (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 1-4below summarize GAMA's four questions, DOE's response, and any discussion ofthese issues that tookplace.


### 1) Question: What is the breakdown for material costs in your analysis on weatherized furnaces? DOEresponse: The breakdown ofmaterial costs-interms ofmaterial, labor, transportation, and overhead-isprovided in Table E.l.3 ofAppendix E ofthe Technical Support Document (TSD) for the furnace andboilernotice ofproposed rulemaking (NOPR). The table also includes the incremental manufacturing cost andDecember 21, 2006

the technological improvements that were made to increase the AFUE ofthe 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? December21, 2006 

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the technological improvements that were made to increase the AFUE ofthe baseline unit.

2) Question: Why are the material costs for the baseline weatherized furnaces more than double that ofthe baseline model for non-weatherized furnaces? DOEResponse: The material costs for the baseline weatherized furnaces include the part costs associated with the 3-ton air conditionerunit, which is usually packaged with the furnace. These costs are also found in Table E.1.3 ofAppendix E ofthe NOPR TSD. Discussion:

• GAMA asked what SEER (e.g., 10) DOE assumed onthe cooling side. GAMA pointed out that a 13-SEERAC 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 efficiencyratings in any detail. DOE was only concerned with the incremental costs that affect the annual fuel utilization efficiency (AFUE) ofthe furnace.

• DOE noted that it assumed the same material costs for the air conditioner throughout the range ofAFUE levels, which allowed DOE to capture the potential effects onthe analysis ifDOE changedthe design options for improving the efficiency ofthe furnace. The weatherized gas furnace unit is described section 6.4.1.1, "TeardownApproach," ofChapter 6 ofthe NOPR TSD. GAMA said that, from a percentage standpoint, the dollar difference wouldbe the same. Ifthe costs are constant, DOEjustneeds 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 woulduse aluminized steel for the heat exchangers ofweatherized 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 ofhigh-volume material pricing. DOE assumed the use ofthis aluminized steel for all weatherized gas furnace heat exchangermaterials regardless ofequipment efficiency as shown in Table E.1.3 ofAppendix E ofthe NOPRTSD. Discussion:

• DOE noted that the only improvement it considered for the development ofthe cost-efficiency curves was the increase inheat exchanger area (no other changes inthe heat exchanger includingheat exchangermaterial).

• GAMA asked what heat exchanger sizes DOE assumed for each AFUE level and noted that manufacturers have to change a lot ofmaterials 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 getup 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 December 21, 2006 

# #146

GAMA stated that some manufacturers believe that the improvement in AFUE with increasedheat exchanger area is not a linearrelationship, as they believe DOE assumed inthe engineering analysis. Intheir opinion, it takes a lot more material to get the incremental benefit ofhigher efficiency.

• Navigant saidthat the TSD does notreport the specific amount ofmaterial 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 ifGAMAhad informationto support a different assumption then GAMA shouldprovide DOE through written comments information aboutthe incremental material costs associated with attaining these higher efficiency levels

overthe baseline, which account for the increase inheat exchanger area. GAMA responded thatthey would try to supply this information in their comment.
4) Question: What are differences in characteristics ofthe insulation material used in the teardown unit versus the improved insulation material that DOE considered? DOEresponse: DOE did not consider different insulation material as a design option for weatherized gas furnaces. DOE initially investigated the effects ofa thicker amount ofinsulation on AFUE in weatherized gas furnaces (the addition of1;2 inch of insulation overthebaseline). 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 onthe furnace efficiency. DOE only considered increasedheat exchanger size in developing the cost-efficiency curves as shown in Figure 6.4.4 ofChapter 6 ofthe NOPRTSD. Discussion: GAMA agreed that manufacturers cannot do much with insulation; it does not have a great impact onAFUE. 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 CondensingLevels on Durability, Performance, andSafety. GAMA described its major concern: GAMA's members would have to make significant changes to their currentproducts 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 extentthat it becomes a safety hazard. GAMA presentedtwo graphs as illustrations:

• Graph 

### 1: CategoryDeterminationforNatural Gas Furnaces. GAMA explainedthat furnace categorization defines the vents needed dependent uponproduct class and is a well established chart and practice used inthe safety standards for gas furnaces. The chart shows the net flue temperature graphed against the percentage ofcarbon dioxide inthe flue products. The line going from a furnace that condenses occasionallyto

one that condenses all the time isjustbelow 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 SSEDecember 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 December 21, 2006 

# #146

of84% ormore in order to meet an 83-percent AFUE standard. GAMA further stated that using the furnace categorization graphs, these types ofproducts would definitely be in the condensing region, which would require Category II or Category IV materials.

• Graph 

### 2: WeatherizedFurnace Flue-Gas-Bearing ComponentSuiface Temperature

vs. Time. The graph shows the surface temperature ofan interior component ofa weatherized gas furnace at different efficiencies (80%, 81.5%, and 83% AFUE). GAMA statedthatthe graph shows that for an 80-percent AFUE, the temperature of the collectorbox surface gets above the dew point in about 2.5 minutes. GAMA further stated that at 81.5-percent AFUE, the collectorbox surface temperature exceeds the dew point when the burner is turning off(approximately at the DOE burner on time of3.87 minutes), and at 83-percentAFUE, the collectorbox surface temperature never exceeds the dewpointtemperature.

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 condensationproblems. GAMA stated that all ofthose 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 ifCategory II and Category IV heat exchangers couldbe manufactured with aluminized steel. One ofthe manufacturerrepresentatives replied that is was possible to make the primary heat exchanger with aluminized steel, butthe condensate drain would have to be 29-4C ("29-4C" is a classification ofstainless steel designed for extreme resistance to chloride ionpitting, crevice corrosion and stress corrosion cracking.)

DOE further asked what is the limit in terms ofSSE and AFUE onusing products which utilize aluminized steel. Further, what design changes wouldbe neededto achieve these types ofSSE and AFUE levels (condensing region). Lastly, what wouldbe the associated cost (incremental) associated with attaining these levels?

GAMAresponded that an 83% AFUE standard would force manufacturers to design products as ifthey were condensing models, i.e., for 90% AFUE, andthat this would

assume the use ofstainless steel andthe associated material costs. In order for GAMA's manufacturers to feel comfortable sellingproducts in the 83-percentAFUE range, which is close to the condensing region, GAMA statedthatthe manufacturing cost would increase due to higher costs for material changes andperhaps an increase in the amount ofmaterial needed for the heat exchanger.

GAMA further notedthat, whenthe categories shown in Graph 1were created, the industry expectedto 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 andDecember 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. December 21, 2006 

# #146

skills, the categories mightbe 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), buthad to recall the products because ofmaterialproblems. 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 abetterunderstanding ofwhat materials would need to be used for condensing weatherized gas furnaces. However, none ofthe manufacturers currently offer these types ofproducts.
Regarding Graph 2, DOE asked about the effects ofrelative humidity. GAMA responded that, while there is a one-to-one relationship for the return air (ifyou 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. Inthose situations, it is not uncommon for theusers to add an economizer, which mixes outdoor air with conditioned air. GAMA described three types ofweatherized furnace applications: a) Residential outdoorunit, with all ducting under a crawl space (typically SE USA) b) Residential rooftop (typically SWUSA) c) Rooftop commercial application. (throughout USA and Canada)

GAMAnoted that a specific problem with condensing furnaces is the question ofwhat to do with the condensate (and pointed outthat none ofthose costs are factored into DOE's analysis). GAMA statedthat potential installation costs should include heated drains to

ensure reliable disposal ofcondensate.

DOE asked ifGAMA considers the actual typical cycle times offurnaces as they are installed in the field, since these mustbe longer than 3.7 minutes. GAMA noted that there are, in fact, a lot ofshort cycles (e.g., on warm days, and with oversizedunits).
Navigant noted that with 83% AFUE furnaces (which never get above the dew point) a lot will depend onthe cycle time. GAMAreiterated that 81.4% AFUE is the highest efficiency they have seen. GAMA speculated that the reason for this is that some manufacturers triedhigher levels and they didn'twork. GAMA further noted that manufacturers cannot design a family ofproducts atthe minimum efficiency standard; they have to account for variability and have an adequate window for compliance. GAMA stated that the cost increases significantly whenthere is such a small window between the maximum level and the minimum standard.

GAMA stated that, to avoid problems, the wettime during a burner on cycle shouldbe 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. December 21, 2006 

# #146

7) Potential for Controls to Mitigate Corrosion. DOE asked ifGAMA 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 behardto reconcile with the test procedure, since they would extendthe burner on-time andthus 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 broughtup the possibility ofthe need for provisions to expel condensate from furnaces. GAMA noted that there are internal traps in the units themselves, butpointed out that the condensate could freeze in the unit ifthe furnace temperature is setback (e.g., while users are onvacation or during night setback). GAMA also pointed out that it wouldbe unacceptable to have condensate dripping out of units and creating potential hazards (e.g., pools ofcondensate, icicles).


### 9) Economizers: GAMA stated thatmore 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'sAssumptions aboutModel Series: GAMA noted that DOE apparently assumed that annual production ofa model series for weatherized furnaces is 100,000 units. However, GAMA's directory identifies nine manufacturers ofoutdoorunits. The bigger ones have 3-6 model series. So, GAMA estimates that the annual production ofa model series is closerto 10,000. GAMA expressed concernthat DOE's overestimation ofhow manyunits an individual manufacturers sells could affect the analysis, since the economics ofrecovering costs is offby a factor of 10.

Navigant agreed that it is importantto get the numbers right, butpointed out that, in the manufacturer impact analysis the actual sales volume bymanufacturer were used to calculate the manufacturer impacts and were provided through the manufacturer interviews. Only about 4% ofthe sales price is due to depreciation (50% is material), so there would be less ofan impact with sales volume permanufacturerin the engineering,

as further detailed in Chapter 6 ofthe FB NOPRTSD.

ACTION ITEMS:

• GAMA will send electronic copies oftheir handouts to Mohammed Khan.

• DOE will circulate the meeting minutes to GAMA for approvalbefore entering them into the docket.