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STATEMENT OF WORK

Project Title:

Reducing the Waste: Improved Fossil Fuel Water Heating Systems

Contractor:

NYSERDA
17 Columbia Circle
Albany, NY 12203-8399
Sacramento, CA 95814-5512
(518) 862-1090 x3214

Program Area:

Building Technologies

Linked Partners:

New York State Energy Research and Development Authority (NYSERDA)

California Energy Commission (CEC)

Energy Center of Wisconsin (ECW)

Project Description:

To prepare for market transformation in residential water heating, the New York State Research and Development Authority (NYSERDA) is partnering with the California Energy Commission (CEC) and the Energy Center of Wisconsin (ECW) on the linked statement of work and related agreements.  The cosponsors will engage three subcontractors: the Lawrence Berkeley and Brookhaven National Laboratories, and the American Council for an Energy-Efficient Economy.  These groups bring unparalleled technical and policy experience.

With STAC funding, the partners will co-fund and manage a three-year, integrated project with five elements:

1. Develop and Evaluate Three Promising, Alternative Storage-type Gas Water Heater Technical Concepts that reduce standby losses and thereby improve seasonal efficiency.
2. Map Performance of Integrated and DHW-Only Systems and Evaluate specific improvement technologies using laboratory emulation methods to develop detailed performance curves and use these to compare annual energy use of different system and control configurations.
3. Document Infiltration Impacts of Gas-fired Water Heaters with Draft Hoods to identify and evaluate the benefits of powered-draft water heaters.
4. Improve the Policy Environment for advanced water heaters, including review of the test procedures, review of conditioned air entrainment, energy economics, and routes to market transformation.
5. Disseminate Information to make market transformation feasible and to support the technical basis for a "Golden Carrot" program of incentives for a new generation of fossil-fueled water heating appliances.

Management Plan

The unique nature of STAC requires that projects be supported by multiple State entities, and to the extent necessary any other entity. As indicated in the STAC Agreement, it is the Contractor’s responsibility to coordinate the execution of work under the Contract, incorporated by reference hereto. Contractor, in conjunction with the other State entities, and to the extent necessary any other entity, shall conduct the project in accordance with the Management Plan described below.

Linked Contractors (State Chartered Organizations)

NYSERDA     New York State Energy Research and Development Authority, Link #1

CEC              California Energy Commission, Link #2

ECW             Energy Center of Wisconsin, Link #3

Subcontractors to Linked Contractors

ACEEE          American Council for an Energy Efficient Economy (subcontractor to NYSERDA Agreement 9102A)

BNL               Brookhaven National Laboratory (subcontractor to NYSERDA Agreement 9102B)

NYSERDA will be the Managing Partner for the contract and serve as primary contact to NASEO.  NYSERDA will be advised by a Steering Committee.  Each State Chartered Organization and ACEEE will designate a representative to the Steering Committee that will meet periodically. The Managing Partner is responsible to NASEO for project execution, and for assuring that the match funds/federal funds ratio remains within an appropriate range during each twelve-month period of the project.  The Managing Partner will report and seek resolution to deviations in schedule, funding commitments or other responsibilities of other State Chartered Organizations, first to the Steering Committee and if need be, directly to NASEO.

ACEEE will serve as Technical Director for the linked projects.  The Technical Director will serve the group and the Managing Partner by providing for quality assurance and task tracking.  The Technical Director will be advised by and advise the Project Steering Committee.  The Steering Committee will also form an independent Advisory Committee of experts who will review progress and suggest improvements that may occur.  The Advisory Committee will receive and review copies of all relevant technical reports.  The Technical Director will be responsible for maintaining the schedule, including preparing reports for NYSERDA and other members of the Steering Committee and the Advisory Committee.

Task 1: Develop and Evaluate Three Promising, Alternative Storage Gas Water Heaters

The team proposes to design, build, and test prototypes of three alternative designs that promise up to 30% better unit efficiency.  The CEC is preparing a Super Efficient Gas Water Heating Appliance Initiative (SEGWHAI) that will generate necessary market pull and foster partnerships to develop cost-effective replacement water heaters.  SEGWHAI units are expected to exceed conventional unit performance by approximately 30% at an incremental retail price in the range of $300.  They will be designed for installation in existing locations without major modifications.

Building on the best practices of past "golden carrot" efforts, SEGWHAI will include integrated development and deployment steps.  SEGWHAI will foster competition and customer choice with incentives based on performance-based specifications.  To encourage the earliest possible sales of SEGWHAI qualified units, higher initial financial incentives will reward the manufacturer who achieves the "first mover" position.  Documented efficiency tests of successful, effective water heaters from this STAC proposal will support the CEC's effort to develop a "Golden Carrot" program to substantially improve gas storage water heater efficiency.  Being able to point to working prototypes will clearly indicate that significant efficiency gains are possible.  Working prototypes will also assist in efforts to design cost-effectiveness production models.

We will use the standard DOE EF 24 hour simulated use test as our measure of energy efficiency.  In addition, we will use tracer gas tests on each design to determine on-cycle and off-cycle air flow through the water heater and the vent, so these energy impacts can be evaluated.

In order of projected increasing cost, the designs to be evaluated include: (1) flue and/or vent dampers for atmospheric equipment, (2) "side-arm" natural draft water heater with storage tank, and (3) induced-draft, near-condensing water heaters with sealed combustion and minimal conditioned air entrainment.

1. Dampers for atmospheric equipment

A damper installed at the top of the water heater flue, below the draft hood, will improve the efficiency of the water heater by reducing off-cycle standby losses.  Patented flue damper designs are available which could potentially cut standby loss by 60% to 70%.  Retail price of these flue dampers could be as low as $20.

2. "Side-arm" natural draft water heater with storage tank

The side-arm design concept would include a separate, atmospheric burner/heat exchanger component that uses thermosyphoning to transfer heated water to the storage tank.  Off-cycle draft losses would be nearly eliminated due to the low thermal mass of the burner/heat exchanger component.  This design eliminates the central flue, the source of most of the standby losses in standard gas-fired storage water heaters.  The reduction of standby losses is expected to be nearly as large as for a flue damper.  The incremental cost of this design would be for the external heat exchanger, minus the cost of a central flue.  The burner, ignitor, and controls would be essentially the same as a conventional gas-fired storage water heater.  A breadboard design has already been assembled and will be evaluated in this project.

3. Induced-draft, near-condensing water heaters, with sealed combustion and minimal cooling air entrainment

Power-vented water heaters are sold today, largely for difficult installations: They vent through the side wall of the house, and do not require a chimney.  However, these units have an EF no higher than the natural-draft models from which they are derived, apparently because of high standby losses.  We are exploring several options to reduce this standby loss, all of which may have commercial potential.  Current designs draw large amounts of air from the space around the water heater to cool the exhaust air enough so that it can be vented through low-cost PVC pipe.  This alternative design would not draw on conditioned air to cool the exhaust gases.

Deliverables:

1. Briefing paper for manufacturers and other stakeholders on the results of the efficiency tests on each of the alternative design water heaters.

Deliverable: LBNL Briefing Paper, Year 1.

Dependencies: The quality of the paper will depend on timely comment and review from collaborators.

2. Technical reports on each of the alternative water heater designs. The technical reports will include the results of the efficiency tests, the measured on-cycle and off-cycle airflow from the tracer gas study and a commentary, including the team's observations and thoughts on how to improve efficiency and manufacturability.

Deliverable: LBNL Technical Report, end of Year 1.

Dependencies: The quality of the technical report will depend on timely comment and review from collaborators.

Task 2: Annual Performance of Integrated and DHW-Only Systems

This task involves using a software (emulation) approach to measure the performance of fuel-fired water heaters and integrated hydronic heating systems which also provide hot water.  The approach is very flexible.  Computer-controlled load patterns will be used that allow easy variation of domestic hot water draw profiles, heat load, and heat delivery system type (e.g. baseboard, radiant floor, hydro/air).  The test standards currently available for equipment in this category are simple to execute, strongly constrained in operating conditions, and intended to provide comparative indication of average annual performance.  These include ASHRAE Standards 103 (furnace and boilers), 118.2 (water heater method of test), and 124 (rating combination appliances).  In the case of boilers, for example, the 103 Standard prescribes supply and return water temperatures of 140/120° F respectively but boilers used for integrated domestic hot water service operate at higher temperatures.  Control concepts that can modify the supply and return temperatures  with season or load patterns are not considered.  The ASHRAE 124 procedure for rating combination space-heating and water-heating appliances is built upon the 103 standard.  The planned procedure to be used in this project will allow testing with a wide range of temperature and control assumptions.  Among the test standards, this approach can be compared most closely to the standard under development for commercial boilers by ASHRAE SPC 155.

The test arrangement which has recently been commissioned by BNL and which will be used for this task is illustrated in Figure 1.  The "system" shown can be an integrated system, stand-alone water heater, or may incorporate both a water heater and a separate boiler.  Domestic hot water and hydronic heating loads are imposed on the system and the system's response, including fuel consumption, is evaluated using a single computer system.  Time resolution for measurements is adjustable but typically 10 second sampling periods are used.  The water flows are directly measured using weigh scales with computer interfaces.  The system operates 24 hours unattended allowing rapid evaluation of very detailed draw patterns over long test periods.  For stand-alone water heaters, the input/output energy performance will be evaluated simply for different assumptions about total load and draw pattern.  The difference between these two cases will be used to quantify domestic hot water heating performance.  As part of work to develop improved hot water draw patterns for use in the 2008 California Title 24 Standards, the CEC will be funding LBNL to evaluate available hot water use data.  This work will use disaggregation techniques on existing hot water usage data to develop improved hot water use pattern from field data, and may be incorporated into the BNL program.  Gas- and oil-fired equipment will be targeted and specific systems to be included in the test program include:

• Typical cast iron boiler with internal domestic hot water (DHW) coil
• Steel boiler with indirect tank for DHW and thermal purge control
• Low mass, wall-hung condensing boiler with instantaneous plate DHW heat exchanger
• Instantaneous, tankless water heater
• Condensing boiler with indirect water heater
• Conventional, gas-fired storage water heater
• Alternative system prototypes developed by LBNL under Task 1

After mapping the performance of the integrated-type water heating equipment, BNL will identify technically and economically feasible improvements, such as thermostat/aquastat controls with broad deadband widths, or boiler thermal post-purge cycles, which would reduce losses that result from boiler cycling.  BNL will perform laboratory testing to quantify the potential energy benefits of such improvements.  BNL will brief hydronic equipment manufacturers on the details of such improvements and testing results.

Deliverables:

1. Performance maps on integrated hydronic heating systems and conventional water heating equipment.

   Deliverable: BNL Report covering test methodology and results for units tested, End of Year 1.

   Dependencies: None.

2. Performance maps on advanced water heating concepts.

   Deliverable: BNL Report referencing report from deliverable 1 and providing results on advanced concept tests, End of Year 2.

   Dependencies: Completion of this task relies on the delivery from LBNL of the advanced concept water heaters.

3. Summary Report on energy consumption with different technical options for DHW production and implications for policies, programs, and manufacturers.

   Deliverable: BNL to submit a report jointly prepared by all linked partners, End of Year 3.

   Dependencies: Completion of this deliverable relies on the completion of deliverables 1 and 2 under this task as well as of the work planned under Task 3.

Task 3: Documenting Infiltration Impacts of Water Heaters

Wit fuel-fired water heaters, energy loads due to combustion and dilution air flows (and required makeup infiltration) have not been well quantified nor accounted for in comparisons of energy alternatives, despite the fact that water heating venting represents a significant hole in the pressure envelope of many homes.  Some believe that the continuous infiltration burden of atmospherically-vented water heaters in cold-climates is particularly significant: under Wisconsin public benefits programs, replacing an atmospheric water heater with a power-vented model and "closing the hole" is credited with 97 therms of annual gas savings, or nearly 10 percent of typical household total annual gas consumption.  These savings estimates - based on engineering analysis - are significantly higher than would be expected based on differences in the Energy Factors derived from current federal test procedures.

This task addresses the lack of empirical data in this regard through two discrete activities: high-resolution field monitoring of draft pressure, and lab correlation of draft pressure with burner and dilution flow.  The work will also support Task 4 providing field data on water heater energy performance and parameters used in test procedures.  We expect these data to provide critical insight into the importance of stack infiltration assessing the energy efficiency of different types of water heaters.

In addition to draft pressures, the monitoring will also include measurements of hot water consumption, water heater energy use, operation of mechanical equipment and appliances (e.g. exhaust fans and clothes dryers) that could affect draft pressure and stack airflow, and ancillary parameters such as basement, living space and outdoor temperatures.  An additional benefit of this monitoring is that it will provide field documentation of back-drafting conditions, such as when dryers or other exhaust equipment overcome flue draft and create spillage of flue products into the living space.  Back-drafting of atmospheric water heaters is of significant concern in low-income housing that has been tightened through weatherization, as well as in new homes which tend to be tighter than average.

In the second year of the study, the atmospheric units will be replaced with power-vented models (a combination of conventional storage and modulating on-demand units) to document differences in on- and off-cycle stack flows with power-vented equipment compared to atmospheric units.  In addition to providing data on the differences in stack losses, this arrangement will allow for a direct field comparison of the energy performance of power-vented equipment versus atmospheric units.

Using the results of these Wisconsin field measurements, Brookhaven Lab will conduct measurements of on- and off-cycle burner and dilution flows for the same equipment models and venting geometry.  A tracer gas technique under controlled conditions will be used.  These measurements will provide a correlation between monitored stack pressure and actual stack airflow for each site.  The flows measured will be integrated with the draft/time distributions measured in the field over the entire heating season to quantify total heating season infiltration associated with water heaters, and provide estimates of the annual energy cost due to these flows.

Deliverables:

1. Technical report on atmospheric water heater monitoring and testing (infiltration loads, back-drafting, field efficiency).

   Deliverable: ECW to submit technical report, middle of Year 2.

   Dependencies: Joint ECW/BNL report based on ECW field monitoring and BNL lab testing.

2. Technical report on power-vented and tankless water heater monitoring and testing (infiltration loads, field efficiency, energy savings).

   Deliverable: ECW to submit technical report, middle of Year 3.

   Dependencies: Joint ECW/BNL report based on ECW field monitoring and BNL lab testing.

3. Briefing paper for policy-makers (infiltration loads from water heaters).

   Deliverable: ECW to submit briefing paper, middle of Year 3.

   Dependencies: ECW publication based on ECW/BNL field monitoring and testing results.

4. Briefing paper for low-income weatherization operators on infiltration and backdrafting findings for low-income homes.

   Deliverable: ECW to submit briefing paper, middle of Year 3.

   Dependencies: ECW publication based on ECW/BNL field monitoring and testing results.

5. Factsheet for builders on infiltration, back-drafting, and energy efficiency findings for new homes.

   Deliverable: ECW to prepare factsheet, middle of Year 3.

   Dependencies: ECW publication based on ECW/BNL field monitoring and testing results.

Task 4: Policy Environment

The term "policy environment" includes a number of distinct elements that affect the ability to market improved water heaters.  ACEEE will lead this work.

Evaluation of Test Procedure

The present DOE test procedure yields a value of EF as a predictor of energy use for heating water.  This procedure has been used without substantial change since the first federal standards took effect in 1990, so review now in the context of water heating technologies is appropriate.  The following issues will be evaluated: (1) Does the present water draw profile (64.3 gallons/day as 6 equal draws 1hour apart at the beginning of a 24 hour test) reflect actual field use and provide realistic information about field energy use?  Lower typical water heater use would reduce the value of capital-intensive solutions.  Changes in draw-timing and volumes would change the relative value of storage volume.  LBNL will be developing typical hot water draw patterns for the CEC to use in Title 24 calculations.  This is part of the CEC's cost-share.  The impact on the measured efficiency of water heaters under these draw patterns will be compared to efficiency under the standard test procedure draw pattern.  (2) The test procedure assumes that the water heater has no impact on the indoor environment.  It assumes that using inside air for combustion and stack dilution has no energy impact on the house.  Atmospheric water heaters rely on natural draft pressure to exhaust flue products.  Back-drafting of these appliances is a concern in older homes that are tightened to improve energy efficiency (low-income weatherization programs) as well as in new homes that tend to be built tighter.  In this environment, states like Minnesota now require or are considering mandatory sealed combustion systems or equivalent to avoid the induced losses of inside air, and consequent depressurization-induced infiltration.  Should the water heater test procedure consider the combustion/dilution air energy budget (For example, the furnace test procedure has different multipliers in it depending on the source of combustion air)?  The issue is compounded because water heaters are sometimes placed in garages, particularly in warmer climates.

Retrofit Cost Implications of Alternatives

Some of the alternatives evaluated in Task 1 and 2 may increase the purchase price of equipment.  Some features of some alternatives will affect installation costs and opportunities.  For example, induced-draft solutions require an electric outlet within a few feet of the appliance.  Neither is likely to be a major barrier for new construction, but both will impact retrofit costs.

Energy Economics

Because some alternatives will increase purchase prices, and some will differentially affect feasibility of new and replacement installations, the team will carry out engineering economic analyses to estimate first cost and life cycle cost impacts for both new and replacement cases.  Progress beyond this study requires understanding whether changes are likely to be cost effective.

Other Barriers

All too often, building codes and other regulations are not friendly to new technologies.  As the team develops and tests prototypes, it will also work with the IECC and other major residential codes to determine which, if any, building codes would require revision to allow use of the new devices.  It is not realistic to expect individual contractors to seek waivers from local codes, or to expect manufacturers to invest in products that will face regulatory barriers.

For the replacement market, sometimes space is at least as much an issue as cost, as revealed in federal standards hearings and documentation.  If resources allow, the team will survey contractors to determine the frequency of "space-constrained" requirements, to see if this could have an independent effect on the market for technologies like side-arm storage water heaters.

Integrated appliances, particularly those with novel control concepts, suffer from low market acceptance because of the lack of high quality information regarding the annual energy use savings.

Finally, what are the routes (such as golden carrot programs) to quickly move the market from present technologies to advanced approaches?  We will consider the potential of the SEGWHAI "golden carrot" and other approaches.

Deliverables:

1. Briefing paper for manufacturers and their trade association (GAMA) on our technical results from tasks 1,2, and 3.

   Deliverable: ACEEE White Paper, Year 3.

   Dependencies: This work is critically dependent on the CEC/LBNL Task 1 work, the NYSERDA/BNL Task 2 work, and the Wisconsin and LBNL Task 3 work.

2. White Paper on how the policy environment this work influences will support introduction of advanced products through incentives and reduction of market barriers.

   Deliverable: ACEEE White Paper, Year 3.

   Dependencies: This work depends on the CEC/LBNL Task 1 work, the NYSERDA/BNL Task 2 work, and the Wisconsin and LBNL Task 3 work.

3. Briefing paper for policy-makers explaining the new technologies and their benefits in the terms that matter to them - and showing the policy changes required to allow these products to conquer the marketplace.

   Deliverable: ACEEE Policy Paper, Second half of year 2.

   Dependencies: This work depends on the CEC/LBNL Task 1 work.

4. Briefing papers for incentive program designers (such as the Consortium for Energy Efficiency, ENERGY STAR, and utility programs).  These will stress savings and how to achieve them, building on concise illustrated technology descriptions.

   Deliverable: ACEEE White Paper, Late year 2 (when preliminary results are available).

   Dependencies: This work depends on the CEC/LBNL Task 1 work, the NYSERDA/BNL Task 2 work, and the Wisconsin and LBNL Task 3 work.

5. Complete technical reports as a foundation for further market transformation work.

   Deliverable: ACEEE Blue Cover Report: Late Year 3 (when results are available).  It will probably serve as a guide to the larger project's results.

   Dependencies: This work depends on the CEC/LBNL Task 1 work, the NYSERDA/BNL Task 2 work, and the Wisconsin and LBNL Task 3 work.

Task 5: Information Dissemination

All the advanced water heater development, documentation of performance, field studies infiltration effects, and policy-related market studies proposed as part of this project are necessary, but they will not change the water heating industry by themselves.  Care will be taken in each of the prior tasks to assure that the knowledge gained will be propagated by publication of peer-reviewed papers and presentations in meetings.  Project Element 5 focuses on information dissemination.  Fundamentally, all of the other elements of this project develop information that is needed for market transformation.  This project will create the foundations for new products (Task 1-3), build an environment in which the benefits of advanced products can be reflected in rating methods (Task 1, 2, and 4) and building codes (Task 4), and thus provide a prerequisite for market transformation programs (Task 4).  Thus, the audiences for our information dissemination efforts are manufacturers, codes and standards authorities, and program planners developing new approaches to bring emerging technologies into the market.

At the extremes, members of these communities need two kinds of information products: (1) short "briefings" that stress results and implications, and (2) solid technical papers that document new opportunities and show how they can be implemented.

ACEEE's Emerging Technologies and Practices report is an example of the first type of work product, containing brief but carefully documented evaluations of new opportunities.  The FEMP Federal Technology Alert series is another excellent model.  One model for the second type of work product is the 1993 publication by Zoi and others, Multiple Pathways to Super-Efficient Refrigerators.  This document showed utilities, regulators and others that there were many cost-effective routes to improving refrigerator efficiency.  Ultimately, it provided a technical basis for the development of the first-ever "Golden Carrot" program for incentives for refrigerators that were more efficient than any products then on the market.  Budget constraints preclude close emulation of this model, but we will produce solid, peer-reviewed, technical papers as deliverables for all appropriate tasks.  Thus, the Task 1 and 2 work leads to papers that can "prime the pump" and get our results to decision-makers.  These results from hardware and emulations will serve the need met in the earlier project by the Multiple Pathways to Super-Efficient Refrigerators report.

In addition, the Contractor will present this work to the audience (manufacturers, codes and standards authorities, and program planners_ at meetings, and make ourselves available for discussions on their terms.  This outreach is a key to influencing policy-makers, manufacturers, and program designers that the advanced water heaters are real and can be good for their organizations and firms.  We plan to arrange presentations for (and meetings with) GAMA (appliance manufacturers), PHCC (plumbing contractors) and other key groups.

Deliverables:

The deliverables for this task are the same as those for Task 4 (listed above) provided by ACEEE.

Project Tasks, Status, and Deliverables

Last Updated: 12/21/06