January 19, 2015

Ms. Brenda Edwards

U.S. Department of Energy

Building Technologies Office

Mailstop EE‐5B

1000 Independence Avenue SW

Washington, DC 20585

Re: Comments on Energy Conservation Standards for Commercial Packaged Boiler Preliminary

Technical Support Document (Docket No. EERE‐2013‐BT‐STD‐0030, RIN 1904‐AD01)

Dear Ms. Edwards,

These comments are submitted by Lochinvar, LLC. in response to the U.S. Department of Energy's

the preliminary TSD related to energy conservation standards for commercial packaged boilers.

Lochinvar, LLC, headquartered in the Nashville, Tennessee area, is a leading manufacturer of

residential and commercial high efficiency boilers, water heaters and pool heaters. Lochinvar has

been in the business of manufacturing boilers and related products since 1939 and became a

wholly owned subsidiary of A. O. Smith Corporation in 2011.

Following are the responses to the 37 questions listed in the Executive summary of the Proposed

TSD.  Additionally, a few comments that do not relate directly to the questions have been

appended to these responses.  We appreciate the opportunity to participate in this process.  

1. DOE requests comment on its tentative decision not to set an upper input capacity limit for

CPB.  

Lochinvar supports the tentative decision to not put an upper limit on input capacity.  The

inclusion of very large products is needed to ensure a level playing field and accurate product

ratings.  Many of the industry concerns related to testing burden are addressed by the revised

AEDM rules.

2. DOE requests comment on the appropriateness of its tentative decision to classify CPBs into

16 equipment classes as described in Table ES.3.2.  

Lochinvar opposes the addition of the new DOE equipment classes and are concerned that

the division will lead to different minimum ratings for natural draft and mechanical draft boilers

and competitive inequality.  We support the current 10 equipment classes.  Commercial water

heaters are available with both natural draft and mechanical draft and have not been divided into

different categories.
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3. DOE seeks comment on CPB standby mode and off mode energy consumption and, in

particular, data on the magnitude of energy consumed in the different operational modes.  

Lochinvar discourages DOE from pursuing regulation of off mode or standby mode electrical

power consumption.  Since measurement of standby mode and off mode energy consumption has

not been required, data is very limited; however, we measurement the standby electrical power

consumption from one of our mechanical draft commercial water boilers which is 0.007% of the

maximum hourly input, a very small portion of the power consumed by the boiler.  The

determination of a seasonal average for standby mode and off mode time will be very difficult to

determine and is not likely to result in substantial energy savings.

4. DOE is interested in views regarding the technological and economic feasibility of the

technology options which successfully passed the screening analysis. In particular, DOE seeks

information regarding technology options which can be applied to improve the efficiency of natural

draft boilers.  

We agree that the technology options which passed the DOE screening analysis are

technologically feasible and appreciate the decisions made by the DOE in this analysis.  In general

terms, increased heat exchanger surface area, baffles and creative fin/pin arrangements are all

viable options to enhance natural draft boiler efficiency and have been implemented by

manufacturers for decades.  While the ratio of surface area to input is directly related to efficiency,

simply adding material to a boiler does not guarantee improved efficiency.  The DOE needs to

consider that design changes are complex and often involve significant redesigns to achieve

efficiency targets without sacrificing safety and reliability.  Near condensing, natural draft boilers

have been available for years.  Condensing natural draft boilers are not economically feasible.   

5. DOE requests comment on the methodology used to calculate incremental costs for

increased efficiency for each equipment class. DOE would welcome comments from interested

parties about the appropriateness of the incremental costs reported as part of the engineering

analysis chapter. DOE would also welcome any additional price‐related information, especially for

natural draft boilers, which would further improve future analyses for this current rulemaking.  

The variation in manufacturing cost and the markup at each stage of distribution makes an

accurate projection difficult, but the DOE methodology seems sound.  The DOE projected cost to

the consumer appears to be a little high (5‐10%) across the board and is assumed to be due to a

modest underestimation of markup.

   

6. DOE seeks input on whether the considered distribution channels are appropriate for

commercial packaged boilers.  

DOE’s considered channels seem accurate.

7. DOE seeks input on the percentage of equipment being distributed through the different

distribution channels, and whether the share of equipment through each channel varies based on

equipment class or equipment capacity.  

Commercial sales for all sizes are primarily (80%+) through manufacturer’s representatives.  

8. DOE welcomes suggestions and comments concerning its proposed approach to developing

estimates of future commercial packaged boiler retail prices.  
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The current method, including interviews seems to be adequate.

9. DOE seeks recent data to establish the markups and commercial consumer price for the

parties involved with the distribution of this equipment.  

While Lochinvar does not have authoritative data, we believe there is some overestimation

of markup.  (Cumulative error is 5 to 10% too high)

10. DOE seeks data on representative annual profiles of return water temperature, supply

water temperature, and boiler percent loading.  

Please see responses to question 11.

11. DOE seeks data on what return water temperatures boilers are tested at under the test

conditions prescribed by the DOE test procedure.  

This question is insightful and very important to the DOE analysis since DOE has stated they

are applying a correction factor based on the difference in test inlet water temperature and inlet

water temperature in typical heating applications.  Previous comments have overlooked an

important aspect of the BTS‐2000 test procedure as it relates to boiler return water temperature.

While clause 8.5.1.1 requires inlet water temperatures between 35°F and 80°F for non‐

condensing boilers and 8.5.1.2 requires inlet water temperatures between 75°F and 85°F for

condensing boilers, there is a subsection covering “tubular boilers that require a greater flow rate

to prevent boiling.”  Most tube type boilers are covered by this clause and a recirculation loop is

used as specified by BTS‐2000 to increase the water flow rate through the boiler.  When the

“optional recirculation loop” (shown in Figure 6 of BTS‐2000) is used the outlet water is maintained

at 180±2°F and the inlet water to the test station is maintained according to 8.5.1.1 or 8.5.1.2, but

the inlet water for the tube type boiler is blended and typically runs between 140°F and 160°F.

Additionally, the DOE needs to be aware that the efficiency curves used in Figure 7‐B.2.1 are

not based on BTS‐2000 test conditions (with 180°F outlet water or maintaining a 100°F

temperature rise).  ASHRAE 155 is being developed so a uniform test method will be available to

accurately project how efficiency changes with system water temperature changes.  Attempting to

use data that was created without a consistent test procedure to project changes in efficiency

based on water temperature is certain to introduce errors.

Since the test inlet water temperatures for tube type boilers and the outlet water

temperature of the efficiency curves are unknown we urge the DOE not to attempt correcting the

efficiency of water boilers for inlet water temperature.  We agree with the intent, but the data that

is being used for the correction is not appropriate.

12. DOE seeks input on data sources that it can use to characterize the variability in annual

energy consumption for commercial packaged boilers. DOE is particularly interested in field

monitoring studies and data.  

Useful studies may be found at www.mncee.org.  We are attempting to locate a particular

study authored by Martha Hewitt.
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13. DOE welcomes any data from interested parties about typical boiler sizing practices,

including how often multiple boilers instead of a single boiler are installed to cover the building

heating load, and how the number of boilers suitable for a specific installation is determined.  

Generally commercial installations will have 2 or more boilers with a total capacity a little

larger than anticipated peak load; however, some applications that cannot accept the risk of

diminished performance will opt for more boilers with at least 100% redundancy. ASHRAE 90.1

requires 3:1 turndown or 3 boilers to provide some measure of load matching for commercial

applications.   

14. DOE seeks input on how boilers are controlled, particularly in multiple‐boiler installations.  

Control options may be integral to the boilers or remotely controlled and include:

• Fixed thermostats

• Fixed lead/lag thermostats with rotation on lead

• Individual thermistors with modulation

• Individual modulation with rotating lead

• Group modulation

15. DOE seeks historical shipment‐weighted commercial packaged boiler efficiency data and/or

shipment data by efficiency bins. DOE is primarily interested in data during the last 10 years in

order to capture the impact of the most current technologies on the boilers market.  

No comment.

16. DOE requests input on ancillary energy use by commercial boilers (i.e., in addition to fuel

energy use) that should be included in the energy use analysis.  

Boilers have some electrical power consumption for controls and blowers where applicable.  

The electrical power consumption is a small fraction of a percent of the total energy usage.

17. DOE seeks input on what fractions of hot‐water commercial packaged boilers are used both

for space heating and hot water.  

Unknown.  We speculate that a greater percentage of residential boilers are used to provide

both space heating and hot water than commercial boilers.

18. DOE requests data to characterize the current distribution of commercial packaged boiler

efficiencies in the market.  

No comment.

19. DOE requests comment on frequency and cost of maintenance, major repair issues, repair

frequency, and repair costs for commercial packaged boilers that meet the minimum efficiency

standards, as well as for higher‐efficiency boilers.  

Manufacturers recommend annual maintenance but evidence supports that maintenance is

often neglected.  Frequency of repair issues varies widely with the construction of the boiler, use,

water quality/treatment, installation and maintenance.  The type of boiler also impacts whether a

heat exchanger failure (major repair) will result in replacement rather than repair.
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20. DOE seeks input on how often boiler maintenance is performed by on‐site staff versus

external contractors, specifically for hot water boilers versus steam boilers and small boilers versus

large boilers.  

Unknown.

21. DOE seeks input as to how often, in the event of a heat exchanger failure; the heat

exchanger alone is replaced versus the entire boiler being replaced. DOE is interested in knowing

whether this varies with equipment class or varies with condensing versus non‐condensing boilers.  

When we are involved in a repair/replace process, the heat exchanger is replaced rather

than replacing the entire boiler for about 80% of commercial heat exchanger failures.  We do not

know the percentages of repair vs. replace when we are not involved in the customer’s decision.  

This is consistent for both condensing and non‐condensing commercial boilers we manufacture.

22. DOE requests data on the fractions of installations that would entail significant additional

installation expenses.  

Unknown.  Speculation: less than 10%.  The additional expense will most likely be for the

installation of condensing boilers with long vent runs that require custom designed common vent

systems with modulating draft control systems.

23. DOE seeks input on how often plastic versus stainless steel venting is installed for

condensing boilers.  

Generally vents 8” and larger are metal and 4” and smaller are PVC/CPVC/PP.  6” may be

either.

24. DOE seeks input on how often boilers have direct venting, for both condensing and non‐

condensing boilers.  

Almost all condensing boilers have the option of direct venting.  The majority of non‐

condensing boilers sold do not have the direct vent option; however, both options are readily

available.

25. DOE seeks input on the fraction of stainless steel venting in existing boiler installations by

efficiency.

There is a very small fraction of near condensing boilers that require stainless steel venting,

but almost all boilers are either designed for non‐condensing conventional vent or condensing with

PVC or stainless steel vent (with the selection of PVC or stainless steel based on size rather than

efficiency).  

26. DOE seeks input on where boilers are typically located within buildings and where the vents

typically terminate. DOE is interested in whether such placements change by geographic region or

boiler type.  

Historically, vent termination has been vertical.  Direct venting options did push toward side

wall venting but resulted in functional problems.  The trend is now reverting to vertical venting for

all products.  Commercial side wall venting is less than 20% and going down.
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27. DOE seeks data on how often common venting occurs in multiple‐boiler installations and

whether commercial water heaters are commonly vented with commercial boilers.  

Multiple boiler installations are often commonly vented (10% and growing).  Common

venting with water haters is more rare, but not unheard of.  We advise against mixing unlike

product types.

28. DOE seeks comments on the methodology used to determine equipment lifetimes for

commercial packaged boilers.  

The projected lifetime for efficiency level 0‐2 is consistent with our experience.  The

projected lifetime for efficiency level 4‐6 is too long and should be 19‐20 years.  Lochinvar has no

experience with efficiency level 3.

Calculations must not aggregate condensing and non‐condensing products for average

lifetime cost calculations.

29. DOE welcomes any data to predict boiler lifetime, particularly for non‐condensing versus

condensing boilers.  

See response to question 28.

30. DOE seeks input on its planned approach for estimating discount rates for commercial

consumers.  

No comment.

   

31. DOE requests data on the efficiency distribution and welcomes comment on the likelihood

and degree of improvement in efficiency of commercial packaged boilers in the next 5 to 10 years

as a result of market forces or industry trends (in the absence of amended energy conservation

standards).  

Editorial comment:  The headings on Table 8‐H1.1 indicate the columns are Mechanical

Draft, but the title indicates the table is for Natural Draft.   

Expanded NOx emission limits will promote the use of higher efficiency boilers, since they

are more likely to comply with the emission requirements than lower efficiency products.  

Increased fuel costs or financial incentives such as rebates will stimulate growth in high efficiency

boiler sales.  The improved design flexibility of venting mechanical draft boilers will result in an

increase in their use.  Additionally, load matching (modulating) boiler controls are most common

on condensing boilers and will be selected when needed for improved comfort and reduced

operating costs.

32. DOE welcomes input on the shipments projection methodology.  

Lochinvar has no comment on the methodology, but the projected rapid decline of natural

draft equipment seems wildly overstated.  Also, the flat projection from 2020 forward suggests that

our national population and economy will be flat.  If the national economy grows, commercial

boiler shipments will grow with it as they are used in manufacturing processes as well as for

heating in office and manufacturing facilities.
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33. DOE invites comments regarding the selection of appropriate economic drivers and sources

of data for historical shipments and shipment breakdowns by equipment class.  

Economic growth and harsh winters and flooding all result in increased demand for

commercial boilers.  All product classes are affected similarly by these drivers.  Oil and gas prices

cause some shift between products and financial incentives from utilities and federal programs

shift shipments to higher efficiency products.

34. DOE seeks historical commercial packaged boiler shipments data, disaggregated by

equipment class and efficiency level if available.  

No comment.

35. DOE seeks input on the potential impact of amended standards on commercial packaged

boiler shipments.  

Negligible as long as non‐condensing, natural draft boilers and steam boilers are not

regulated out of existence.  The higher the new standard goes the more significant the impact.

36. DOE seeks comments on the appropriate assumptions to use regarding long‐run changes in

commercial packaged boiler energy efficiency independent of amended energy conservation

standards.  

Focus on providing part load performance characteristics to allow the best boiler selection

and promoting efficient system design.   

37. DOE requests input as to what consumer subgroups are appropriate to evaluate for

commercial packaged boilers.  

Interview mechanical contractors and design engineers who more directly impact product

selection and system design.  They will have a hand in virtually all usage of commercial boilers and

can help identify any consumer subgroups not already considered by the DOE.

   

Additional comments:

The DOE has applied a conversion factor to combustion efficiency to thermal efficiency for

projected energy savings.  The conversion is a linear relationship where every 1% increase in

combustion efficiency equates to a 1.0867% increase in thermal efficiency.  The DOE has not

mentioned any intent to reverse that conversion factor when setting new minimum combustion

efficiency levels for large commercial packaged boilers.  In other words, if the DOE determines that

a 2.0% increase in the minimum allowable thermal efficiency is justifiable that result justifies an

increase of 1.8% to the minimum allowable combustion efficiency.  The DOE will need to justify a

greater energy savings for large commercial boilers in order to justify an increase in combustion

efficiency in order to account for the conversion factor.  We encourage the DOE to avoid this

confusion and not convert the combustion efficiency to thermal efficiency.
2. 7 Energy Use Analysis states that the DOE estimated that 16 percent of commercial 

packaged boilers are installed in residential buildings. 6.2 Distribution Channels states that the DOE 

estimates that 5.5 percent of total commercial packaged boiler shipments are to residential 

applications. This inconsistency should be reviewed and corrected. 

Lochinvar, LLC. appreciates the opportunity to provide these comments. If you have any questions 

regarding this submission, please do not hesitate to contact me. 

Regards, . 

Jeff Kleiss 

Product Certification Engineer 

Lochinvar, LLC 

300 Maddox Simpson Pkwy 

Lebanon, TN 37090 

P: 615.889.8900 X: 2224 

jkleiss@lochinvar.com 

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