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Reference Publication:   Chandra, Subrato, Neil Moyer, Danny Parker, David Beal, David Chasar, Eric Martin, Janet McIlvaine, Ross McCluney, Andrew Gordon, Mike Lubliner, Mike McSorley, Ken Fonorow, Mike Mullens, Mark McGinley, Stephanie Hutchinson, David Hoak, Stephen Barkaszi, Carlos Colon, John Sherwin, Rob Vieira, and Susan Wichers. Building America Industrialized Housing Partnership, Annual Report - Sixth Budget Period. 4/1/04 - 3/31/05.
Building America Industrialized Housing Partnership, Annual Report - Sixth Budget Period

II. BAIHP Technical Assistance (N)

  • Nez Perce Fish Facility
    Cle Elum, Washington

Three SGC homes were built at the Nez Perce tribal fish facility in Cle Elum, WA. One of these homes is equipped with Energy Star appliances and lighting; all three homes are heated with Insider heat pumps. Monitoring equipment was installed in Year 2. In Year 3, preliminary blower door testing indicated a high leakage rate. During Year 4, tests found significant duct leakage due to failure of butyl tape at risers on 2 year old home. (See also Section III Research Zero Energy Manufactured Home.)

  • New Generation Homes
    Ft. Myers, FL
Figure 31 New Generation Home

Ken Kingon of New Generation Homes became a BA partner at the end of the 5 th budget period. Of particular interest is the performance of the high efficiency 5 ton 15 SEER AC system and the use of outside air ventilation (measured air flow = 32 cfm) to the air handler. A house was tested and instrumented in February 2005 by FSEC researchers, showing that duct leakage and air tightness are consistent with new home construction, there are opportunities for improvement. The HERS score is 87.9.

  • Northwest Energy Efficient Manufactured Housing Program (NEEM)
    Idaho
    Oregon
    Washington (State)

The Washington State University Energy Program (WSU), together with partners Oregon Office of Energy and Idaho Department of Water Resources, Energy Division, continue to provide technical and research support to the Northwest Energy Efficient Manufactured Housing Program (NEEM program in the Pacific Northwest. The NEEM program involves 20 plants in three states, hundreds of retailers and thousands of homebuyers.

The NEEM program includes the brands Super Good Cents and ENERGY STAR, and includes homes heated by electricity and Natural Gas/propane. Prior to 2003, the NEEM program also included the Natural Choice brand, which was exclusive to homes heated with Natural Gas or propane. In 2003, the Natural Choice brand was phased out; now, all gas heated homes are branded ENERGY STAR. In 2004, a new path for ENERGY STAR was developed for Super Good Cents homes with electric furnaces. Homes will be built to this path beginning in 2005.

In the fall of 2004, NEEM staff began to provide technical assistance to Champion Homes on a 700 unit private military modular housing development at Ft. Lewis. In-plant verification, certification and on-site verification of these homes began in spring of 2005 and will continue as a major BAIHP effort.

In the fall of 2004, technical assistance by NEEM staff to the Energy Trust of Oregon resulted in the development of a million dollar utility incentive program that promotes the production of a more NEEM homes built to higher benchmarking levels consistent with BAIHP goals. A technical analysis of the ETO program has been provided to FSEC.

Throughout the BAIHP effort, WSU staff provided technical assistance and guidance to the NAHB Research Center Energy Value Housing Awards, judging submittals, providing de-briefing to builders, and participating on workshops. NEEM builders Fleetwood, Champion, Valley and Marlette have received EVHAs for factory built housing.

Aligning with New Building America Goal

In the summer of 2004, BAIHP staff performed a benchmarking evaluation to assess the improvement of NEEM homes over the entire BAIHP project period (note that this evaluation was included in the Year 5 (April 2003 – March 2004) annual report). The benchmarking was based on a home defined by NREL (built to IECC requirements). The savings over the benchmark home were estimated using version 2.2 of Energy Gauge USA. Evaluations were performed for a typical 1600 ft 2 double wide home with 12% glazing to floor area (the NEEM fleet average) in three Pacific Northwest climate zones: Portland, OR; Spokane, WA; and Missoula MT.

The homes were benchmarked assuming a continuously operating whole house ventilation system, resulting in a significant thermal energy penalty. Additional benchmarking was also conducted using the 164 kWh/year ventilation assumption in the NREL benchmark, in an effort not to penalize the homes for improved IAQ associated with HUD whole house ventilation system requirements and ASHRAE 62.2.

In 2004-2005, improvements were made to NEEM HVAC systems and duct specifications as a result of BAIHP research (see Refinement of NEEM Specifications, below.) Additional benchmarking is presented that reflects these improvements.

The results of the benchmarking vary considerably by HVAC type, water heat and climate, as noted in Table 19 below. Some key observations:

  • In all climate zones, electric homes result in negative savings if the ventilation penalty is assumed. This is largely the result of the assumption that the benchmark home has a heat pump that performs without installation problems; an assumption that will be evaluated by BAIHP research.
  • Gas heated NEEM homes came closest to meeting the overall BAIHP goal of 40% over the NREL benchmark, but only met the goal if gas heat is paired with electric water heat, in cold climates with no ventilation system penalty.
  • Eliminating the ventilation system penalty has a higher impact on benchmarking results (9 to 23 percentage points) than improved duct leakage tightness (3 to 11 percentage points).
  • It should be noted that Benchmarking these NEEM homes against the HUD-FMCSS requirements (Uo=.079) for manufactured homes rather than the IECC (Uo=0.06) would yield considerably higher savings than current benchmark assumptions.

Table 19 Benchmarking Savings Results

Duct Leakage

Pre-2004*

2004**

Pre-2004*

2004**

Ventilation System Penalty

Yes

Yes

No

No

Portland

Electric Furnace

-31

-20

-8

0

Heat Pump

11

14

20

22

Gas Heat/Elec DHW

16

22

32

37

Gas Heat/Gas DHW

15

20

30

34

Spokane

Electric Furnace

-18

-9

2

10

Heat Pump

17

21

27

30

Gas Heat/Elec DHW

22

27

36

41

Gas Heat/Gas DHW

21

26

35

39

Missoula

Electric Furnace

-12

-3

8

15

Heat Pump

17

22

28

32

Gas Heat/Elec DHW

21

26

35

40

Gas Heat/Gas DHW

20

25

34

38

* Pre-2004 – Duct leakage of -132 cfm@25PA
** 2004 – Duct leakage of -60 cfm@25PA


Figure 32 shows, by program year, the number of homes produced with technical assistance from BAIHP, as well as the number of homes submitted for ENERGY STAR designation by BAIHP staff and the breakdown of homes by benchmarking score. Please note the following:

  • The benchmarking includes the assumption, based on the NEEM 5 th Budget Period random that showed 24% of all homes included after-market heat pumps.
  • No benchmarking was performed for Years 1 and 2, due to a lack of accurate regional data.
  • In 2003 and 2004, the appearance of homes that achieved a 30+% benchmark is the result of the improvements made to the NEEM HVAC specifications.
  • Figure 32 averages benchmarks for Spokane and Missoula for homes in cold climates and uses the Portland benchmark for marine climates. Figure 32 also assumes an average value between ventilation penalty and no ventilation penalty.

The continued success of the program is due to several factors. BAIHP and NEEM staff worked to increase awareness within the manufactured housing industry of the marketing value of energy efficiency, increase participation by utilities in incentive programs, and promote the co-branding of NEEM with ENERGY STAR.


Figure 32 Homes Produced with BAIHP Technical Assistance

The increase in ENERGY STAR designations is due to refinement of the SGC duct sealing specifications, resolving a discrepancy between the SGC specifications with ENERGY STAR’s duct sealing protocols (while this question was being resolved September of 1999 through early 2001, BAIHP staff did not submit homes to DOE for ENERGY STAR designation). In 2003, remaining discrepancies with manufacturers in Idaho were further resolved, allowing BAIHP staff to accurately report all qualifying homes.

Refinement of SGC specifications

BAIHP staff continually work to refine the existing SGC specifications, a result in large part to innovative building technologies researched in BAIHP.

In 2003, BAIHP staff worked with NEEM staff and manufacturers to develop revisions to NEEM specifications, including allowing only mastic for duct sealing, requiring metal flex duct for whole house ventilation fans, and changing the air infiltration specification from 7.0 ACH 50 to 5.0 ACH 50.

The revised specifications were voted on and accepted by the manufacturers; they took effect on January 1, 2004.

In year 2004 in Oregon, 1 in Idaho plant began testing the ducts in all the NEEM homes they produce, which is expected to result in even tighter duct systems. Field testing of a sub-sample of these homes duct testing began in 2004 and continues. This field testing is also evaluating homes that employed a “thru-rim” crossover duct system.

BAIHP staff continues to work with EPA and other regional partners on clarifying the equivalency of SGC with ENERGY STAR. In 2002, BAIHP staff developed a new ENERGY STAR compliance path for climate zone 2 that does not require a heat pump. The non-heat pump path uses a heat recovery ventilation system, a .93 EF hot water heater and tighter ducts and envelope. This path was not utilized due to reluctance by manufacturers to install HRV systems. In 2004, this path was modified to eliminate the HRV, and include options such as set-back T-stats, ENERGY STAR dishwasher, adjusted glazing limits, improved window U-factors, and in-plant tested duct systems.

Revised In-plant Manual

In 2003, in light of the revisions to the NEEM specifications, BAIHP staff from the Oregon Department of Energy developed an updated in-plant inspection manual, with new graphics, including details on correct installation of heat recovery ventilation. Many of the manual updates are the result of BAIHP research and demonstration efforts, including use of hybrid floor systems and proper duct sealing with mastic. The manual also now includes a regionally consistent problem home inspection protocol.

In-plant QC Training

In 2004, BAIHP staff from the Oregon Department of Energy developed a PowerPoint presentation, based on the revised In-plant manual. In 2004, BAIHP staff began using this presentation to train QA staff at each plant; this effort will continue until all NEEM plants have received this training.

In-Plant Inspections

On a quarterly basis, BAIHP staff visits each of the manufactured housing plants to verify compliance with SGC/E-Star specifications. Inspections include a plant audit, ventilation system testing, and troubleshooting construction-related problems with plant staff and independent inspectors. Consistent issues in the plant include wall insulation compression or voids due to improper cutting of batts, attention to duct installation and air sealing. Specific in-plant inspection reports conducted in Washington in program Year 6 (March 2004 – April 2005) are provided to FSEC.

Transition to mastic

As mentioned above, the NEEM program eliminated the use of butyl tape for duct sealing, and required the use of mastic. As of spring 2004, ten manufacturers have successfully transitioned to mastic. Testing in-plant has indicated significant improvement in duct leakage rates of homes in these factories– an average 36.8 cfm @ 25 PA (versus 50.1 cfm @ 25 PA pre-mastic), a 27% improvement. This trend continued into 2005.

WSU and ODOE began working with Fleetwood engineers to evaluate a new lower cost duct leakage testing device that Fleetwood is considering using in all of its plants throughout the USA. The preliminary results suggested a need utilize 10 second averaging and set a higher pressure ratio from 86% to 90% to be consistent with NEEM duct leakage targets. This work will continue through program Year 7.

Duct Workshops

Through the spring of 2005, BAIHP staff continued to provide workshops focused on improved duct installation and inspection oversight, working in partnership with BAIHP partners. One in-plant duct leakage workshop resulted in the identification of significant duct leakage (branch disconnect) which re-enforced the need to consider duct testing of all units at that plant.

New Technology Evaluations

High Efficiency Gas Furnaces

Figure 33 90% AFUE Furnace, as installed at Kokanee Creek

Initial evaluations of 90% efficient gas furnaces indicates that there is no incremental installation cost to the use of these furnaces, as no field modifications are required. In 2003, Nordyne and Evcon came out with furnaces with an appropriate footprint for manufactured housing; Intertherm also continues to offer a 90% efficient model. Discussion with BAIHP home manufacturer partners Fuqua, Marlette, Champion, and Fleetwood, and furnace manufacturer partners Evcon and Nordyne, indicate the that this market is growing quickly, especially in homes with high pitch “tilt-up” roof systems, and multi-story homes such as at Nogi Gardens and Kokanee Creek. The ability to use wall venting instead of roof venting with condensing furnaces makes them more attractive where tilt-up roofs are employed.

Through the rim crossover duct system

Three Oregon manufacturers, Marlette, Skyline and Homebuilders Northwest, adopted a crossover duct system that runs through a cut out section of the rim joist, effectively placing the entire crossover system in the heated space. A gasket on the marriage line provides a seal between sections. Challenges with the use of this system include the need for very accurate measurements to insure matching of the duct connection, and careful treatment of the gasket material during set up, so that it doesn’t detach from the rim.

Evaluations suggest that that further improvement to gasket systems may be needed to ensure set-up that achieves effective duct sealing.

La Salle Duct Riser

BAIHP staff worked with BAIHP partner La Salle Air to design and produce a duct riser for manufactured homes that uses mastic instead of tape. BAIHP staff demonstrated prototype designs of the riser to Northwest manufacturers in Year 3. Most NEEM manufacturers adopted the new risers or equivalent systems in year 6. . BAIHP staff worked with Fleetwood’s national office to promote the use of the riser in all Fleetwood plants. During 2003-2004, BAIHP staff promoted the use of this technology at the annual MHI conferences and energy road-mapping meetings.

Flexible Technologies:

BAIHP partner Flexible Technologies has developed innovative systems that improves the heat and tear resistance of the duct inner liner, reduces the crimping of ductwork without the use of sheet metal elbows, and an improved system to air seal where the crossover duct penetrates the bottom board. BAIHP staff evaluating the use of this system in the WSU Energy House and ZEMH, and worked with Flexible Technologies staff to promote the use of the new system to the region’s manufacturers. Efforts to gain market adoption of the technology remain challenging due to first cost increases and lack of demonstrated benefits.


Figure 34 Insider Heat Pump in ZEMH and Base Home –
Operation in HP and Strip Heat Mode

Insider Heat Pump

Monitoring of the Insider heat pump at the WSU Energy House was begun in 1999. Measured flow rate of the indoor unit was good (850 CFM total, 425 CFM per ton), but BAIHP staff identified two performance issues: a too-frequent operation of the defrost cycle and a lower than expected airflow at the outdoor coil. Continued testing of the Insider in 2002 indicated a 10% increase in COP due to increased airflow at the outdoor coil. At Vincent Village, the property manager indicated a high degree of satisfaction with the Insider heat pumps, with no comfort complaints. Flip flop testing that varies the compressor and electric resistance heat were conducted in the WSU and ZEMH. The results of those tests being analyzed for a ASHRAE paper to be submitted in 2005. The Insider Flip flop test results are presented in Figure 34.

Energy Conservatory

BAIHP staff work with the Energy Conservancy (EC) to evaluate their new products for measuring air handler and exhaust fan flows. In 2004, BAIHP staff worked with EC staff to develop an automated test that will provide duct leakage to outside. Discussion with EC indicated significantly increased sales of duct blasters to HUD-code manufacturers as a result of BAIHP efforts. WSU continues to work with EC to develop new building science tools for HUD-code housing.

Other Technologies

In 2004, BAIHP staff submitted a status report summarizing program efforts to introduce BAIHP manufacturers to new technologies. The report highlights the barriers and successes made regarding:

  • 24” OC Wall Framing
  • Air-Tight Can Lighting Fixtures
  • Solar Ready design
  • Improved flashing/drainage systems
  • High Efficiency Water Heaters
  • Blown Cellulose Hybrid Floor Insulation
  • Condensing Gas Furnaces
  • Heat Pump Water Heaters – Site built
  • Hi-R wall Systems (Foam Sheathing + Icynene) – Site Built

Research Support

ASHRAE

During 2003, in the capacity of chairing ASHRAE’s 6.2 Technical committee, BAIHP staff directed a major effort to revise Chapter 9 of the ASHRAE Systems Handbook, “Design of Small Forced-air Heating and Cooling Systems.” The revisions to the chapter, which incorporated BAIHP research, were accepted by the committee, and forwarded to ASHRAE for publication. In 2004 BAIHP staff provided assistance to other BA teams to improve chapter 43 of the ASHRAE Applications Handbook – Envelopes.

BAIHP staff have also participated in ASHRAE research projects, conferences, symposiums, seminars and forums, including:

  • Authoring a paper on duct leakage, which was submitted and approved for presentation at ASHRAE summer meeting in 2004.
  • Making a presentation at the ASHRAE summer meeting in 2003, “Uncontrolled Air Flow in Small Commercial Buildings.”
  • Moderating a forum on HVAC experiences in HUD code housing at ASHRAE’s summer meeting in 2002. 20 industry and building science professionals participated in the forum.
  • Co-chairing ASHRAE’s Technical Committee 6.3 – Residential Forced Air Heating and Cooling Equipment, which is responsible for ASHRAE standard 152 – Thermal Distribution Systems.
  • Building America research on ductwork and HVAC systems will be included in the next version of the ASHRAE standards. Building America research will also be a part of future efforts in TC 6.3.

NFPA-501

BAIHP continues to support the NFPA standards process. The NFPA standard is typically incorporated into the HUD code, which governs the construction of over 250,000 HUD code homes each year.

  • In 2003, BAIHP staff integrated BAIHP duct leakage and cost data into proposals to the NFPA-501 committee. Based on this data, NFPA approved a new standard on duct tightness, as well as a refined duct testing protocol.
  • In 2002, BAIHP staff cited Building America research and demonstration efforts in support of additional successful proposals for standards revision, including duct testing, and use of mastic in duct sealing.

ACEEE

  • BAIHP staff have co-authored two papers presented at ACEEE Conferences, “Pushing the Envelope: A Case Study of Building the First Manufactured Home Using Structural Insulated Panels,” and “Washington State Residential Ventilation and Indoor Air Quality Code (VIAQ) - Whole House Ventilation Systems Field Research Report.”
  • In 2004, BAIHP staff coordinated 24 peer reviewed papers for the Residential technologies track at the Summer Study and coordinated informal sessions on HUD-code housing.

National Institute of Standards and Technologies (NIST)

BAIHP staff continues to work with NIST staff and industry representatives to evaluate ventilation and IAQ issues in HUD code homes.

  • BAIHP staff also worked with NIST and the Energy Conservancy to perform tests on a typical HUD code model house on the NIST campus in Gaithersburg, Maryland. Testing indicates low flow rates of the whole house ventilation system and significant duct leakage.
  • In 2004, discussions with NIST, LBL, Ecotope and Energy Conservatory continued on a retrofit research effort with Dupont Tyvek, and development of new ventilation system controls with Panasonic. These discussions will continue.

National Manufactured Housing Research Alliance (MHRA)

BAIHP staff continues to participate on MHRA’s ENERGY STAR committee, which is developing Quality Assurance procedures with USEPA on ENERGY STAR manufactured homes. An article on the ZEMH appeared in the MHRA newsletter. WSU worked with MHRA to provide an article on the ZEMH project. WSU continues to provide technical support to MHRA on ENERGY STAR and other building science/energy related efforts such as the MHI roadmap.




Disclaimer: This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.

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