Completed Research Projects

Building America in Alaska (12/02)

The Cold Climate Housing Research Center, the U. S. Department of Energy and Alaska Housing Finance Corporation formed a state/industry partnership to implement the Building America program in Alaska. A "Building America in Alaska" team of building industry professionals from across the state worked with cold climate experts from the Building Science Consortium. The primary goal of this project was to develop plans for energy efficient, durable, healthy, and cost effective homes affordable to moderate income Alaskans.The team designed a single-family residential home with modifications for each of three major climatic regions/environments found in Alaska. Building America homes using the CCHRC design or Building America technology have been constructed by Bee Construction in North Pole (Interior) and blu-Spruce Construction in Juneau (Southeast). These homes were readily accepted in the marketplace and sold upon or prior to completion. The performance target for these homes is Five Star Plus, which is the highest level of efficiency. A Final Report was delivered to AHFC October 30, 2001, and included the building design, material list, construction costs, and performance testing and energy modeling of the finished buildings. The plans are available from CCHRC. CCHRC staff worked with the Fairbanks Chapter of Habitat for Humanity to utilize the Building America design and technology in their projects. The "Builders Guide: Cold Climates" developed through the Building America program was reviewed by the Alaska team and CCHRC staff, and recommended updates compiled and delivered to the Building Science Consortium. Click here to view a CAD rendition of Building America Design.


A full set of plans is available in PDF format below:

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Building America in Alaska II (12/04)

CCHRC was awarded a second grant from the Department of Energy for a State Energy Program Special Project award to continue our work on the Building America program. The goals: 1)to develop builder's education courses on BAA approaches to residential construction and to continue education and promotion of Building America techniques to the Alaskan building industry; 2)testing and monitoring of the Building America houses constructed in Alaska in 2001 to assess their performance; and 3)to develop a Building America strategy to address the cold, wet climate of Southeast Alaska which will include construction of a test module for testing wall panels for moisture, durability and energy efficiency. A power point presentation of the 4 hour class is available from CCHRC. A Final Report is included here. The CCHRC Mobile Test Lab (MTL) was constructed in North Pole and shipped to Juneau in January 2003. Students of Construction Technology at the University of Alaska SE constructed and monitored various wall systems in the test module for a year. MTL photo The REMOTE wall out performed other wall sections in terms of drying. The Final Report has been submitted to AHFC. The MTL has new wall panels, new equipment and is continuing to be monitored under funding from AHFC. Please see Mobile Test Lab under Current Research.

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BEES Study (1/02)

The CCHRC was funded by Alaska Housing Finance Corporation to undertake a written economic analysis of the proposed changes to the Building Energy Efficiency Standards (BEES). CCHRC contracted with Northern Economic Research Associates (NERA) to complete the analysis. The analysis included life cycle costs of compliance including initial construction costs and long-term maintenance costs. Direct benefits shall be measured through improvements in energy efficiency, health or safety related impacts consequent to air quality and other environmental improvements, as well as changes in structural durability and occupancy comfort. Indirect economic impacts on community employment resources, and availability of housing shall be included. NERA completed the survey and the Final Report was forwarded to Alaska Housing Finance Corporation (AHFC). A summary report was published the CCHRC Quarterly Newsletter. Click to view the Summary Report

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Four Star Plus, Five Star, and Five-Star Plus Energy Rated Homes Survey & Analysis (2/02)

Six responses were received to the RFP and Ivan Moore Research (IMR) of Anchorage, Alaska was awarded a contract on July 26, 2001. IMR has conducted a customer survey of Four Plus and Five-Star Plus homes to determine customer satisfaction and understanding of building components. A mail questionnaire was completed by IMR and mailed to homeowners. IMR has completed the survey and evaluated and analyzed the energy use data (actual vs. energy rating estimates). Click to view the Executive Summary

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Evaluating Residential Heating Systems (12/03)
Please see published article in Energy Design Update:
"Furnaces In Alaska Are Oversized," Energy Design Update, March 2003, pg. 8-9.

The CCHRC, through a grant from Alaska Housing Finance Corporation, contracted with Arctic Energy Systems (AES) to measure the actual design heat load of houses by monitoring the runtime of the furnace in relation to outdoor temperatures. The study monitored 20 houses in the Anchorage area during the very cold weather. The goal of this study was to better determine appropriate heating system sizing for the HVAC industry to reduce building costs and improve the efficiency and comfort of homes. A Final Draft was received by CCHRC in July 2002 and was peer reviewed in August. Click to view the Final Report

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Evaluating Ventilation Systems with Regard to Indoor Air Quality (1/03)

The CCHRC, through a grant from Alaska Housing Finance Corporation, contracted with Alaska Building Science Network (ABSN) to monitor 100 relatively new homes in 3 different climatic regions in Alaska (Anchorage/Matsu, Juneau, and Fairbanks). Monitoring consisted of relative humidity, particulates, and VOC's. The goal of this study was to provide an evaluation of the extent to which various factors, including ventilation strategies, house characteristics and location, and occupant usage affect indoor air quality. ABSN obtained 13 CO data loggers from the Municipality of Anchorage and included Benzene in their testing. Click to view the Final Report

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Best Management Practices for Rain Catchment Systems in Alaska (3/03)

This study was recommended by our board member, Chuck Dearden, from Ketchikan. CCHRC developed a project with the Institute of Northern Engineering/Water and Environmental Research Center and received project funds from AHFC. The objective of the study was to prepare a best management practices (BMP) in regard to materials and methods of rain catchment systems for domestic water collection, storage and distribution. A short publication and a materials list is available under Reports.

Funding for this project went through UAF to hire a graduate student, Ms. Corianne Hart, in the Environmental Quality Science program. Corianne is continuing her study of rainwater catchments under funding provided by the EPA funded Alaska Technical and Training Assistance Center (ATTAC) (http://www.geocities.com/~water-alaska/). Our goals are to enlist participants who currently use rainwater for in-home use. During the summer 2003 samples will be collected from some of the systems to test for common pollutants. CCHRC funding initialized this research program in rainwater catchments.

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Mold Survey (4/03)

In early March, 2003, we were contracted by the HUD Office of Native American Programs (through Magna Systems) to do a rapid survey of mold problems is Alaska Native Housing. By mid-March we contacted 73 of 88 regional or village housing authorities in Alaska. The following table summarizes the information obtained. In total, we documented over 1700 apartments or homes that had some level of mold problem. These likely vary from mild mildew around windows, in kitchens, or in bathrooms to severe mold development that will require the destruction of the building. HUD recognizes the seriousness of this issue and is providing training to housing workers at Native housing authorities around the Nation. CCHRC has been funded by AHFC to provide some consulting services to Alaska Native housing authorities on a variety of housing issues, including low-cost ventilation systems. Adequate ventilation is one of the keys, along with good moisture control, to maintaining a healthy, mold-free home. Click to view the Mold Survey.

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Improving the AK Warm Design Heat Loss Calculation (1/03)

CCHRC, through a grant from Alaska Housing Finance Corporation, contracted with Arctic Energy Systems to develop computer software that calculates the design heating load of a home, so that the home's heating system is properly sized. The software presents the results in an industry-accepted report. The software is operated via the user's Internet web browser and is freely accessible to all users across the Internet. You can test the AK Warm Design Heatloss calculator here. We encourage you to test it and send us your comments.

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Healthy Homes In Alaska (updated 3/05)

The Alaska Housing Finance Corporation (AHFC) partnered with the Cold Climate Housing Research Center (CCHRC) to conduct Healthy Homes project activities in Fairbanks and in Hooper Bay. The purpose of the Healthy Homes Initiative was to demonstrate cost effective, preventive measures to correct health hazards in the home environment that produce serious upper respiratory illness in children. This was a two-year project that included the University of Alaska and State Weatherization Agencies. The Healthy Homes project added additional services to the weatherization protocol addressing the sources of moisture in the home and the removal and replacement of water-damaged materials and furnishings. It also assessed the effect of resultant changes in indoor air quality on the health of the residents. Whether and how older housing can be successfully remediated, or whether housing funds should be prioritized to new housing is an important decision for AHFC and HUD. A Final Report was sent to HUD in March 2005 and is available from CCHRC on a CD. Click to view the Executive Summary by CCHRC Research Director, John Davies.

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Statewide Housing Survey (9/05)

This project updates and extends the 1991 Housing Needs Assessment Study conducted by the ASK* Marketing Research Group for the Department of Community and Regional Affairs. CCHRC hired Information Insights to assemble the 2000 Census Data and other data sources and conduct an additional survey to fill any gap. The final report of 200 pages with an additional 100 pages of survey results is available from CCHRC in PDF format. An executive summary can be viewed here. The data sets will be archived at AHFC. Click to view the Executive Summary.

Remediation of Smoke Particles in Fairbanks Homes (3/05)

This summer 2004 project was initiated in response to and in the midst of the heavy smoke in the Fairbanks area due to wildfires. Bill Reynolds of Solutions and Cathy Cahill of the University of Alaska conducted a emergency study to improve indoor air quality and address simple and affordable filtration strategies. Systems were installed in houses of people with a history of respiratory problems and air quality was monitored. Click to view the Summary Report.

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South Central Ventilation Study (5/06)

Click to view the Full Report.

The Cold Climate Housing Research Center (CCHRC) commissioned John Freeman of Sunrise Energy Works to study the Skuttle ventilation technique in new housing in the Anchorage area during the winter and spring months of 2004. This study monitored nine houses in a new subdivision to assess the effectiveness of their Skuttle ventilation system and their compliance with the Alaska Building Energy Efficiency Standard (BEES) ventilation requirements.

The Skuttle system consists of a six-inch duct bringing outside air into the return side of the furnace plenum, thus pulling fresh air into the house when the furnace fan comes on. Either two or three bathroom fans exhaust stale air. Each bathroom exhaust fan has one of three different controls: a manual switch, a dehumidistat, or a timer. The control for each bathroom fan operates independently and none of the controls interconnects with the furnace fan supply. The bath fans operated a very small percentage of the time, thus, the Skuttle system operates primarily as a "supply only" ventilation system when the furnace fan is on.

This study compared the total effective ventilation rate calculated from measurements in each house to the BEES requirement. Each house in the study has a furnace-fan-integrated supply duct (Skuttle) and bathroom exhaust fans. During the study, motor loggers monitored the runtimes of the furnace and the bathroom fans. These fan runtimes and initial airflow measurements provided estimates of the mechanical ventilation rate in each house. Blower door tests of the houses were used to estimate the natural air leakage contribution. Results were used to calculate the daily averages of the total effective ventilation rate. All of the houses were occupied, and data recorded reflected the occupants' normal living patterns.

The BEES allows for a combination of mechanical ventilation and natural air leakage to provide the required ventilation flow rates. AHFC testing policy excludes air coming through the crawl space and garage in calculating natural ventilation flow rates. That exclusion left an average of 38% of natural air leakage usable for ventilation.

The daily average mechanical ventilation airflow provided by the Skuttle ventilation system, as operated by participants in this study, ranged from 6.4 to 40.8 cubic feet per minute (CFM). The runtime for the furnace fan supply was more significant to the amount of mechanical ventilation than the type of bathroom fan control. The total mechanical ventilation flows alone did not provide the 90 to 140 CFM ventilation rates required by the Alaska BEES for these houses. Homeowners may turn off noisy fans, thereby reducing the contribution of bathroom fans to mechanical ventilation.

Estimates of the natural air leakage contribution to ventilation varied widely. Several participants left crawl space vents open for the study period, while vents were closed in other houses. The air leakage model assumes leakage is evenly distributed throughout the house envelope. If actual leakage is largely in the crawl space, and the upper house is relatively tight, then airflow through the upper envelope will be reduced, and will be overestimated by the model. Calculations of the daily average total effective ventilation were likely over-estimated for the houses in this study that had crawl space openings. Calculations range from 73 CFM to an unlikely high of 657 CFM.

To better assess ventilation effectiveness, several other indoor air quality (IAQ) parameters were monitored for the four-month study period. Measurements of carbon monoxide and benzene levels showed a pattern of garage-to-house pollutant transfer, carbon dioxide (CO2) accumulated in bedrooms at night, and decayed slowly. These results support the estimates of relatively low total effective ventilation. They also reinforce the probability that the higher estimates of natural infiltration misrepresent the actual contribution of infiltration to the total ventilation. The pollutant transfer pattern and the CO2 buildup also indicate that mechanical ventilation is more important than natural infiltration in distributing ventilation air effectively.

If the system design had provided balanced flow by linking the bathroom exhaust fans and the furnace supply, it would have been possible for it to meet the BEES ventilation requirement. Balanced flow is possible with an interlocking control that operates the furnace supply and bathroom exhaust at the same time.

Balanced flow gives better source control for clean supply ventilation air. Exhaust-only ventilation (when just bath fans are on) tends to pull air from polluted crawl space and garage zones and likely increases ventilation needs. Supply-only ventilation (when just the furnace fan is on) tends to drive moisture into walls and ceiling assemblies.

The recommended improvements for the Skuttle system in this study are to provide interlocked control on the furnace supply and bathroom exhaust fans and to switch to low-noise bathroom exhaust fans. This would increase the effective ventilation flow rates with better distribution to bedrooms and give balanced ventilation with cleaner source air.

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REMOTE Wall Study (9/06) Live Data

Introduction

In 2002, CCHRC undertook a simple study of the performance of two residential dwellings built with different wall systems. One was a standard wall system with an interior vapor/air barrier and the other was a modified PERSIST wall that has been named "REMOTE" which stands for Residential Exterior Membrane Outside Insulation Technique. This was a short-term data collection period as the buildings were monitored from the first of December 2002 through March of the same year. The results of this short term data collection period can really only be used to predict possible long term performance and should not be construed to imply a thorough evaluation of wall system performance of the building over a substantial period of time.

PERSIST uses an approach in which the roof and walls are sealed with a membrane on the exterior of the sheathing and all the insulation is exterior to that membrane. A second roof is then constructed to provide and overhang and protective roofing material. This study hoped to show that by eliminating the extra expense of a second roof, and instead using a traditional cold roof found in most northern construction, that the principals behind PERSIST would be transferable to residential construction in a cost effective manner.

Methodology

The study consisted of three main parts: (1) monitoring the moisture performance of the REMOTE wall, (2) estimating the cost premium for the REMOTE wall system compared to a standard wall system in two homes built in Fairbanks by the same builder, and (3) comparing the fuel usage of the REMOTE house to that estimated by AkWarm. The complete final report for this study can be found on the CCHRC website. CCHRC has also produced a DVD that shows the process used in constructing a REMOTE house that is available for $15. The results of this study are summarized in the conclusions below.

Conclusions

In this relatively short study, the REMOTE wall system performed quite well. Even with the addition of insulation in the interior stud cavity, the interior of the sheathing never approached the dew point, the temperature at which condensation might occur. The air tightness of the REMOTE house was about 0.4 ACH50 compared to about 2 ACH50 for the standard house. This means that very little energy is wasted heating infiltration air but, like any tight wall system, requires a good mechanical ventilation system. The air tightness also appeared to slightly increase the effectiveness of the fiberglass batt insulation in the stud cavity from a nominal R-11 to an effective R-13. Moisture probes of areas vulnerable to rainfall using a Delmhorst moisture meter indicated moisture levels well below any level of concern.

The cost of the REMOTE wall system is somewhat higher than the conventional system, but apples-to-apples comparisons are difficult to make. In this study, including labor, we compute the REMOTE wall to cost about $0.85 more per square foot of heated space (including the garage) than the conventional approach. Other estimates, that exclude labor, put the cost premium at about $0.30 per SF of heated space. For a 2,500 SF house, the REMOTE premium would be about $1,500 (assuming the labor costs to equal the materials cost) to $2,125 (based on the $0.85 per SF premium) over the conventional wall system. CCHRC is continuing to research ways to reduce this cost; but this cost seems worth the benefits of a healthy, durable home.

There remain questions about the fuel-usage rates observed in this study. The REMOTE home appears to be using fuel at a rate almost twice what was predicted by the AkWarm analysis (which was very low). This rate is not overly excessive compared to other highly rated homes; but is higher than was expected for such a well built home. Given the insulation values and the air tightness results, this is unlikely to be an envelope issue. The best explanation to-date is that the boiler is oversized and the standby and stack losses are using the extra fuel as compared to the predicted rate.

Click to view REMOTE snapshot with wall details.
Click to view Final Report.

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Health House VOC Monitoring (9/06)

Through a grant from Alaska Housing Finance Corporation, CCHRC contracted with Alaska Energy Associates (AEA) for data collection of Volatile Organic Compounds (VOC) in various new homes in Fairbanks and Juneau. The purpose of this project was to assess the effect that different ventilation strategies have on indoor air quality. The study dwellings in both communities included a "Health House," a non-mechanically ventilated 5 Star home, and a 5 Star-Plus home with a heat recovery system for ventilation. The Fairbanks "Health House" tested is also a Habitat for Humanity house. Testing took place pre-occupancy, soon after occupancy began, and 6 months following occupancy. The final report has been revised to report corrected data. Click to view the Final Report.

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Mobile Test Lab - Wall Systems for Southeast Alaska (12/18/06)

CCHRC contracted with UAS to continue Marquam George's work in testing wall sections appropriate to SE Alaska in CCHRC's Mobile Test Lab. The data logging design, equipment acquisition and set up were contracted to Balanced Solutions. Click to view the Final Report from Balanced Solutions.

 

Combustion Air/CO Study (2/20/08)

CCHRC, through a grant from Alaska Housing Finance Corporation, conducted a combustion air evaluation in the Fairbanks area. The purpose of the study was to assess sufficiency of current practices in combustion air supply for atmospherically vented heating appliances, and assess the performance of power-vented appliances. Each house was be measured and evaluated to determine (1)house and combustion appliance zone (CAZ) surface area and volume; (2)common wall surface area and leakage; (3)air leakage of house and CAZ; and (4)the amount of combustion air (vented and ambient). CCHRC staff met with individuals who are reviewing codes for the City of Fairbanks Code Review Board and presented data collected from this study on combustion air requirements for oil-fired boilers. This information was incorporated in new code requirements and adopted as an amendment to the 2000 International Mechanical Code. View the Final Report.

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