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3883 Route 30 (PO Box 457) Jamaica, VT 05343 Ph: (802) 874-7222 Blower Door Test Results and Findings: Introduction: The blower door is a valuable tool to the energy auditor and is used to quantify air leakage in buildings. The process is quite simple and involves sealing a large fan into an exterior doorway. The fan is connected to a digital monometer that reads pressure and airflow. The pressure gauge is set up to read building pressure relative to outside air pressure, and the flow is measured by connecting an air hose between the fan and an input tap on the monometer that measures airflow in cubic feet/minute @ 50 pascals (cfm50). Once set up a building can either be pressurized by blowing air into the house, or depressurized by pulling air out of the house. The most common method used by an auditor is to depressurize a building 50 pascals relative to outside air pressure. After pressure is stabilized by either reaching 50 pascals, or by maximizing the exhaust capability of the fan, the air flow is recorded. This air flow measurement is exactly equal to the amount of air coming into the house through air leaks in the building envelope. Once the airflow is recorded a number of important ventilation calculations can be made, the most important of which is determining the difference between the actual air exchange of the house, and the standard for adequate ventilation of the structure. This standard is prescribed by the American Society of Heating and Refrigeration Engineers (ASHRAE) and is referred to as the Building Tightness Limit (BTL). Blower Door Results Building Depressurization: -12.5 Pascals Air Exchange: 16000 cfm50 Airflow measured through the fan during depressurization totaled 16000 cfm50. This air exchange rate is extremely high and is slightly more than 3.5 times the rate required by ASHRAE's ventilation standards for buildings. The minimum air exchange rate (BTL) converted to cfm50 for the building is 4,500 cfm50. The excess air exchange in the building represents a hole in the thermal boundary approximately 1,150 square inches in size. Reducing the high air exchange rate should be one of the primary focuses of any remediation work and will significantly increase comfort and reduce energy consumption. As a result many of the recommendations made in this report are directed towards reducing air exchange. It is important however, to consider how various building components are connected and that in many cases one problem may not be solved without first addressing another. Solutions and Recommendations Upper Thermal boundary and attic areas: The greatest reductions in energy consumption in Dalrymple will be attained by making improvements to the air barrier and increasing thermal insulation levels along the upper thermal boundary of the building. Many improvements to the buildings heat retention characteristics have been made over the years, and the attic areas are no exception. These improvements however, were not conducted recently and as a result do not reflect today's energy prices or the likely higher energy costs of the future. Much of the work to improve efficiency was focused on adding additional insulation. Simply adding insulation without first conducting aggressive air sealing work will result in less than satisfactory results. Furthermore, the cellulose insulation used at the time the building was insulated contained sulfates for fire suppression. These sulfates, when exposed to moisture will create sulfuric acid that can corrode any metal such as wiring, nails, and other metal building components. Cellulose treated with 100% borates as a fire suppressant should be used on all historical buildings. Due to the sulfur content in the previously used cellulose, and the need to effectively air seal the flat attic areas of the building, Thermal House recommends removing all existing cellulose insulation from the building. This can be accomplished by utilizing a commercial grade gas powered vacuum. The vacuum can be located outside of the building. Large dust free bags are placed inside a dumpster and a long vacuum hose is brought inside the building allowing the insulation to be removed without creating substantial dust or disruption to the daily activities within the building. Once the insulation has been removed air sealing can take place. Air sealing will involve plugging all air leakage pathways connecting the conditioned space of the building to the attic areas. Plumbing and wiring penetrations will be sealed using expandable foam insulation. Rigid foam board insulation will be used to block off the slanted ceiling sections, and caulking will be used to seal interior wall openings. Weather stripping and rigid foam board will be used to create airtight and insulated attic hatch openings. After thoroughly air sealing the upper thermal boundary dense pack cellulose will be installed in the slanted ceiling sections, and loose fill cellulose will be applied to the flat attic areas. The goal for treatment of these areas will be a decrease of 50% in air exchange, and an increase in thermal performance of R-50 on all flat attic areas, and R-30 along all slanted ceilings. The areas behind the knee walls along the fourth floor will be incorporated within the thermal boundary. All existing insulation will be removed from the roof slants, and 6" of spray applied closed cell foam will be applied from the top of the knee wall to the third floor upper exterior wall plate. The gable end wall sections behind the knee walls will be insulated with 6" of open cell spray applied foam, and all knee wall gable end vents will be permanently sealed. The work behind the knee walls will not only significantly reduce heat loss, but will improve heating system distribution efficiency by bringing the heat pipes within the thermal boundary. Basement/Crawlspace and Combustion Appliance Zone: Effective moisture management must be a top priority whenever significant reductions in air exchange are incorporated in the work scope. This is especially true when working on historical structures. Point sources of moisture such as the section of the basement where the old cistern is located should be effectively sealed off from the building. The best way to accomplish this would be to incorporate an internal drainage system that diverts all incoming water into a sump pit, where the incoming water is then pumped out of the building. All exposed dirt would be covered by a vapor barrier and sealed to the exterior walls. These walls could then be sealed and insulated using a high density spray applied closed cell foam. The cistern would need to be retrofit with an air tight water resistant cap that would eliminate water vapor from escaping into the air. Benefits of these improvements would include: effective moisture control, reduction in air infiltration through the porous stone foundation, and decreased conductive heat transfer through the un-insulated foundation walls. For health and safety reasons, as well as improving energy efficiency the combustion appliance zone should be isolated from the building. All air pathways connecting this are to the building should be effectively sealed, and outside air should be ducted directly to the boiler. Depending on the burner type, it is likely that an aftermarket outside air boot is available for the burner. If not, ductwork from the outside can be vented into the area to supply necessary make up air for the heating system. This improvement will help to reduce negative pressurization of the lower floor area which in turn will reduce air infiltration. Furthermore, it will allow the building's air exchange rate to be lowered without impacting combustion draft. * Sizing of makeup air must be in strict conformance with manufacturer specifications. Windows: The majority of windows in the Dalrymple building are single pane glass windows that lack an effective air seal. The thermal performance of these windows can be significantly improved by adding weather stripping where needed, and tightening up the sashes. All loose or broken panes of glass should be replaced, or re-glazed, and sash locks may be installed to secure any sashes that are loose in the jambs. Other than improving the air tightness of the existing windows, a strategy should be developed to improve thermal performance by utilizing interior storm panels, insulated window shades and/window quilts. The numerous southern facing windows that provide significant light and potential for winter time solar heat gain should be retrofit with insulated interior storm panels. It is important that custom made, and tight fitting panels be used to reduce condensation and deterioration of the window sill and lower sash. Several custom made, but poor fitting interior storm windows have been installed in the building already, and there is evidence of window deterioration, most likely due to the formation of condensation over the heating months. All northern exposure windows should first be air sealed as previously described, and then equipped with insulating window quilts. Insulated window quilts have a significant ability to reduce heat loss through windows. The only drawback is that they must be pulled closed when light through the window is not required. The eastern and western facing windows should undergo the same air tightness retrofit work, and depending upon the amount of available light they offer, either an insulating energy panel, shade or window quilt should be installed. General Air sealing/Blower Door Directed Air Sealing Significant blower door directed air sealing can be conducted along the exterior wall sections of the building. The infrared images which capture numerous air leaks through the building envelope can be used as a guide to effectively reduce air exchange. Weather stripping, caulking, backer rod, and expandable foam insulation will be used where appropriate to seal openings to the outside. Exterior Walls Currently there is a mix of old fiberglass and cellulose insulation in the exterior wall cavities of the building. Adding dense packed (3.5#/cubic foot) cellulose insulation will not only improve R-value, but will greatly help to reduce the buildings high air exchange rate. The procedure would involve removing several rows of clapboards along the exterior facade at each floor level. Once removed a 2" hole would be drilled through the sheathing and a wall tube would be inserted into the wall cavity. Each stud bay would be dense packed with cellulose insulation, the holes in the sheathing would be plugged, and the clapboards would be refastened to the walls. Any damaged clapboards would be replaced with historically correct material. Reducing electrical consumption: See general improvements. Alternative energy source potential The excellent southern exposure of Dalrymple lends itself well to the incorporation of solar energy. Either photo voltaic generated electricity or solar hot water are excellent options for future consideration. The large cistern located underneath the building could be incorporated into a solar hot water system and used as a storage tank. The tank could be super-insulated with spray applied foam to efficiently store hot water. Hot water generated from this system could be sued for both domestic hot water and heating of the building.