Other Projects

The Chancellor’s residence at Appalachian State University is a beautiful and welcoming setting for many university events, yet the 6,300-square-foot building had persistent problems with comfort and moisture. HPBS assessed the building enclosure, using a rigorous visual inspection protocol and infrared thermography, and quantified air leakage with a commercial building blower door test. HPBS found major design and construction flaws in the air barriers and thermal barriers. The building’s air leakage rate was 3.5 times leakier than allowed for similar renovation projects on military bases. HPBS provided a scope of work for correcting the problems including a cost estimate and potential energy savings.

Energy bills were high at Livingstone College, and students and professors were feeling plenty of cold drafts during the winter. As part of a campus-wide efficiency master plan, HPBS engineers evaluated 18 buildings on campus using ASHRAE infiltration estimating methods to identify sources and to quantify the magnitude of air leakage occurring due to issues with the metal single-pane windows, roof-to-wall intersections, door and window weather-stripping, and roof exhausts. In addition, some of the buildings needed air sealing and insulation to separate the attic air from the classrooms. Recommendations were made to resolve numerous moisture problems as well.

Older buildings can be beautiful, historic, and centrally located, but they often have high energy bills. The Randolph County Arts Guild, located in an old building in downtown Asheboro, asked HPBS team members to conduct an energy assessment. HPBS engineers used eQUEST modeling software to predict the energy savings for several recommendations, which included lighting retrofits, HVAC replacement, window sealing, and turning off furnace pilot lights during summer. In addition, roof and gutter replacement were recommended to prolong the life of the structure. HPBS estimated the cost for each measure and presented the guild with a list ranked by the cost-effectiveness. Implementing all of the recommendations was expected to reduce energy bills by 24% annually.

Out of reach to power lines since the undersea power cable was damaged in 1963, Alcatraz Island has relied on expensive generators that sucked up as much as 2,000 gallons of diesel fuel a week. The high cost of power is one reason the prison closed. Today it’s part of the Golden Gate National Recreational Area. The National Park Service decided to invest in solar photovoltaic panels for the island to save money and reduce pollution. But before purchasing the panels, they wanted to evaluate opportunities for using less energy. They also wanted to increase the efficiency of the generators, which are still needed as supplemental power. HPBS team members conducted a detailed energy audit of the island, which at the time had no electric meters.  HPBS recommended replacing very inefficient lighting and control strategies. They also recommended replacing an oversized generator with several high-efficiency modular generators to be used as a solar-diesel hybrid power system to optimize efficiency as demand fluctuates.

HPBS provided the inspection and verification needed for the EPA’s Energy Star program for 20 education buildings in the Henderson County school district, including not only schools but also the school district’s IT and computer training center. An Energy Star building uses less energy and is less expensive to operate. All buildings certified are in the top 25% of energy-efficient buildings.

McGrath, Alaska, is rural town above the Arctic Circle whose isolation results in electric rates over 30 cents per kwh. The town contacted HPBS team members for help in finding a more affordable source of energy than transporting fuel year-round via riverboat for the aging and inefficient diesel-powered electric power plant. With the aid of a computer model called HOMER, HPBS engineers evaluated least-cost ways to meet the electric needs of the community. The most cost-effective solution was to use multiple smaller generators in combination with a 100-kilowatt solar photovoltaic array and battery storage. This hybrid strategy would save summertime fuel costs during the peak sunlight hours and rely on the bank of efficient generators primarily during the sunless winter.

A nonprofit association in Raleigh sought help from HPBS to address excessive heating costs. The association asked for suggestions for low-cost energy conservation measures since they weren’t planning to stay in the 6,900-square-foot building long term. HPBS found that the newer HVAC units in the building used only inefficient electric coils for heating. HPBS recommended adjusting the programmable thermostat schedule, using energy conservation modes for computer equipment, identifying and sealing substantial air leaks identified with the aid of a blower door, replacing degraded gaskets in the single pane storefront window, and replacing weather-stripping on the exterior doors.

HPBS helped the congregation be good stewards of the environment by identifying energy conservation improvements for the 6,600-square-foot sanctuary and the 10,000-square-foot classroom space. Recommendations included adjusting controls for the energy recovery ventilation and outdoor air dampers, controlling exhaust fan operation based on carbon dioxide levels, adjusting the heating set point for occupied and unoccupied hours, replacing fluorescent lights with LED tubes, and using a blower door to identify and seal air leaks in the building envelope.

As a condition of purchase, a 120,000-square-foot, 6-story, 43-year-old office building required a property-condition assessment that included a standard ASHRAE Commercial Energy Audit. While performing the audit, HPBS engineers identified measures that would reduce energy use by 30%, including lighting retrofits, occupancy sensors, air sealing, and window film installation.

A new 15,000 square-foot clubhouse in a gated golf community on the North Carolina coast developed worrisome symptoms shortly after completion: water droplets on the AC vents, water stains on ceiling tiles, water dripping out of the HVAC closet, and a moldy smell. HPBS found that the building’s air barrier was completely absent in places, particularly behind the tongue-and-groove cathedral ceilings, which allowed outdoor air to flow into the building, bringing plenty of coastal moisture with it. If unaddressed, this intrusion of warm moist air could destroy the beautiful cathedral ceilings within a few years. A constant negative pressure in the building compounded the problem by actively sucking in the moist outdoor air. HPBS provided specifications to retrofit the air barrier and recommended HVAC modifications to create positive pressures in the building.

During design and construction of the 138,000-square-foot Transient Wounded Warrior Lodge at Walter Reed Hospitals Complex, HPBS was contracted to provide consulting on the building enclosure. This included a design review of the plans and specifications, quality assurance inspections, air leakage testing of windows, and final air leakage testing services as part of the U.S. Army Corps of Engineers project requirements for building envelope commissioning in new buildings. HPBS served on the committee to develop the Army Corps of Engineer’s air leakage testing protocol, which has launched significant advances in building enclosure integrity throughout the country and is the basis for many air leakage testing specifications.

HPBS responded to concerns about moisture and comfort in Stemmler Hall at the University of Pennsylvania. The university was planning a major renovation of the building and wanted to make sure moisture issues and comfort concerns were appropriately addressed during the renovation. Air leakage tests and inspections with an infrared camera uncovered major flaws in the design and construction of air and thermal barriers. There was also an unacceptable amount of air leakage around metal frame windows that were renovated in 2004. HPBS provided a scope of work and cost estimate for correcting the flaws along with computer-modeled savings from the improvements.

The HVAC system in a new dining facility could not keep up with heating and cooling in the 29,000-square-foot kitchen and dining hall. An HPBS review of the mechanical equipment revealed that the HVAC system was not adequately sized in light of the numerous kitchen ventilation hoods. Furthermore, air leakage tests and infrared thermographic inspection showed a large amount of uncontrolled air leakage at the roof-wall transition that were hidden behind I-beams and greatly increased the load on the HVAC system.

After a historic building was converted into a combination office and living space, moisture stains appeared on the second-floor walls. The owners contacted members of the HPBS team to find out why. Using an infrared camera, team members discovered that warm humid air from the living area was leaking around the perimeter of the rigid insulation boards in the roof assembly and into the parapet. During cold weather the water condensed on the interior of the roof membrane that wrapped the parapet. This condensation had dripped back into the living space and stained the walls. Removing the roof membrane and sealing perimeter of the roof insulation resolved the problem.

A 300,000-square-foot multistory army barracks constructed using factory built modular units were experiencing buckling of floors on its upper levels. HPBS team members have extensive experience in modular construction and uncovered that the moisture originated from the crawlspace and migrated through the interstitial spaces between the floor modules into the floor assemblies and resulted in the water damage problems. Sealing holes in the crawl space to prevent air leakage was recommended to fix the problems on the second and third floors.

A new, three-story, 50-unit, modular condominium building went together so fast that the roofing contractor was unable to keep up. Unfortunately, rain leaked through the unfinished roof. Modular units typically include many water-sensitive materials from the in-plant assembly phase, such as gypsum wallboard and carpeting. For that reason, risk of damage from water intrusion during the onsite work is much greater than for other forms of construction. HPBS team members took immediate action to call in commercial dehumidifiers to dry the building and monitored progress to minimize water damage and to ensure proper completion of the roof.

During construction of a 238,580-square-foot building at Ft. Bragg, HPBS engineers performed quality assurance inspections and discovered a recently installed air barrier was inadvertently damaged by other sub-contractors. Repairing it before installing the brick veneer prevented future moisture problems and a much more costly repair. After construction was complete, HPBS conducted a thermography inspection and tested for whole-building air leakage and found that the building met the U.S. Army Corps of Engineers air leakage requirements.

Getting HPBS involved during the design process of a building is a great way to avoid problems with moisture, comfort, or high energy costs later. HPBS performed a design review of the two 57,500-square-foot buildings at Fort Bragg and identified potential deficiencies in the enclosure design that could be fixed before construction began. The design review also identified key items and a schedule for inspections during construction. After construction was complete, the HPBS team conducted a thermography inspection and tested the buildings for air leakage. Because HPBS had been involved from the start, the buildings easily met the U.S. Army Corps of Engineers air leakage requirements.

Two five-story hospital towers were experiencing moisture intrusion issues. Hospital administrators were in the process of building a first-floor addition but needed to resolve the moisture problems above it first. HPBS determined that rainwater was entering the walls because the exterior insulation and finish system (EIFS) had ineffective flashing. In addition, the window glazing system had shrunk over time allowing water to enter the window assembly. HPBS recommended re-glazing the windows for a short-term solution and isolating the new addition with new through-wall flashing to prevent moisture from the old buildings entering the new one. As a long-term solution, HPBS recommended replacing the windows and developing a program for regularly maintaining the EIFS system.

A 325,000 SF candy-manufacturing facility in Tennessee was struggling with numerous water intrusions that appeared to be roof leaks. However, the problems had not been resolved through traditional roof repairs. HPBS inspected the facility and discovered that it was operated under an excessive negative pressure, which caused large volumes of outside air to be sucked into the roof assembly. Because the outdoor air was generally quite humid and much if the interior of factory was refrigerated, water condensed inside the multi-layered roof assembly. This resulted in water leaking into the plant from the ceiling, unrelated to any roof leak. The assessment also uncovered condensed water trapped on top of the metal roof deck that was causing premature rusting. Correcting the negative pressure called for HVAC repairs to bring in makeup air as needed and separating spaces that required exhaust fans (like the shipping and receiving docks) from spaces that required positive pressure. The water leaks were eliminated, but more importantly untimely failure of the roof deck was avoided.

A 100-year old manufacturing building converted to produce silicon chip circuits was experiencing product failure due to contamination. Airborne particles from their adjacent factory were drifting across the parking lot and contaminating manufacturing processes. Clearly this was a job for strategic air sealing of the buildings. While conducting the air leakage assessments and tests, HPBS engineers identified sources of leakage, which included a roll-up door with no weather-stripping, multiple penetrations through the concrete block walls and the poured concrete ceiling, and leaks around the wood stud walls. After these leaks were sealed, air leakage testing was repeated and the building met the air-cleanliness requirement for contaminant-free production with room to spare.

Before construction of a 60,700-square-foot building at Fort Bragg, HPBS performed a design review and identified potential issues that could be modified to prevent problems in building performance. During construction, quality assurance inspections by HPBS discovered mistakes in the spray polyurethane foam application, which were fixed before the brick veneer was installed. After construction, the HPBS team conducted a thermography inspection and tested the building for air leakage. The building met the U.S. Army Corps of Engineers air leakage requirements.

A 33,000-square-foot public services building undergoing a renovation had a history of moisture problems and high utility bills. HPBS performed an air leakage test, which revealed a high level of leakage, and provided a scope of work to reduce the infiltration without requiring a major building shell renovation. HPBS conducted quality assurance inspections during the repairs of the building envelope, and performed a follow-up air leakage test after repairs were completed. Air leakage had been cut in half. Not only were moisture and high utility bills reduced, but also lower capacity HVAC equipment could be specified due to the reduced load.

HPBS performed a building-enclosure design review and identified potential deficiencies that could be modified before construction of a 114,200-square-foot barracks. During construction, quality assurance inspections by HPBS identified deficiencies in the spray polyurethane foam application in the unconditioned attic that were corrected before the building was finished. After construction, the HPBS team conducted a thermography inspection and tested the building for air leakage. The building easily met the U.S. Army Corps of Engineers air leakage requirements.

HPBS worked to ensure good air quality before and after construction of this 110,500-square-foot medical clinic. HPBS developed an Indoor Air Quality Management Plan for the construction phase and measured the indoor air quality after construction with the U.S. EPA Compendium of Methods for Determination of Air Pollution in Indoor Air. The building passed the test without a time-consuming air quality flush-out procedure.

The occupants of this 12,000-square foot office building complained of humidity, odors, and uncomfortable temperatures. HPBS investigated and discovered an incomplete air barrier at the roof and floor assemblies. The concrete slab floor was built over a crawl space, and was riddled with holes, which allowed odors, moisture, and unconditioned air to enter the offices. HPBS developed specifications for the necessary repairs which included creating a sealed attic and sealing all penetrations in the floor. HPBS generated bid documents and assisted the facility manager in hiring and providing quality inspections for the repairs.

HPBS conducted over 8,800 quality assurance inspections under contract to a national company providing utility-scale energy conservation measures on both small and large apartment complexes throughout both North and South Carolina. The inspections reviewed efficient lighting and water efficiency installations to ensure measures were installed correctly and to document any missed opportunities.

Smith Street Station is an apartment building in Charleston, WV, managed by the Religious Coalition for Community Renewal, a nonprofit that helps provide housing for low-income residents. The building consists of 30 apartments and shared common areas. The building was constructed in 1990 and since then, utility bills have climbed steadily, cutting into the resources available for the organization’s mission. We investigated and found that when individual terminal air-conditioning and heating units in the apartments failed, they were being replaced with units using electric strip-heat, which is not an efficient choice for the West Virginia climate! We calculated that the electricity usage in the building could be reduced by 27% by replacing the units with more efficient heat-pumps, and by sealing air leaks, replacing windows, and upgrading to more efficient water heaters.

During construction of this 65,800-square-foot building, the fluid-applied air barrier was installed before the walls were capped at the roof line. Rain subsequently damaged the air barrier before it had a chance to cure, causing it to bubble and peel off the concrete-block walls in some areas. We discovered the improper sequencing and resultant damage during quality assurance inspections. That meant the air barrier could be reapplied correctly before it was covered up by the brick veneer, avoiding a much more costly repair in the future. We then performed air-leakage tests on the building at completion, using eight computer-controlled blower door fans. The building passed the US Army Corps of Engineers air leakage requirement with flying colors.

When the schools in Springboro, Ohio, were having problems with high utility bills and moisture, they contacted HPBS. Our engineers conducted air leakage testing and a building enclosure assessment for five schools. We uncovered major air leakage resulting from design and construction flaws and also found moisture damage that was a consequence of the uncontrolled air leakage. We then developed a scope of work for correcting the problems, along with estimates for the remediation costs and energy savings. We also conducted pre- and post-testing to quantify how much the air leakage had been reduced. The schools reduced their overall air leakage between 11.6% and 16.3%, shrinking the heating and cooling costs and increasing comfort as well.

In 1989, Sewanee university renovated and added air conditioning to Quintard Hall, a building originally constructed in 1900. Unfortunately, this addition created unintended consequences in the form of excess moisture. The university contacted us for help.

Our team inspected and found multiple pathways for moisture to enter the building. The replacement windows installed in 1989 allowed water and humid air to enter around the windows and through the exterior wall assembly. The addition of exterior staircases with vents connected to the crawlspace, coupled with the negative pressure from the HVAC system, brought additional humid air into the building. Furthermore, the original historic building was not designed for air conditioning, and the masonry walls, when cooled, absorbed and stored water.

We recommended replacing the windows, sealing air leaks in the crawlspace and mechanical rooms, and installing a spray polyurethane thermal and vapor retarder on the interior side of the masonry wall. While these repairs were being made, we also provided quality assurance inspections and performance testing.

A newly constructed school in the Charlotte-Mecklenburg system had higher than anticipated utility bills and was not comfortable for the teachers and students. The school system had hired other consultants who concluded that the HVAC system was performing properly. Our team performed a whole-building air leakage test and found excessive air leakage. Next, they looked to see where air was coming in. They found gaps at the transition between the exterior wall and the roof, and at the transition between the concrete block construction and the framed construction. To avoid difficult-to-repair problems like this in the future, HPBS has worked with Charlotte-Mecklenburg Schools to develop air-barrier specifications and testing protocols for new construction projects.