NC-2009 EAp2: Minimum Energy Performance Required

Table G3.1.1A lists two possible categories for the building heating source: (1) Fossil fuel, fossil/electric hybrid, & purchased heat; (2) Electric and other. In cases where the proposed building design includes both a natural gas heating source and an electric heating source, when should the heat source in Table G3.1.1A be identified as "Fossil/Electric Hybrid" versus "Electric"?

This project consists of the rehabilitation of a one-story brick warehouse in downtown Phoenix, Arizona, built by the Arizona Hardware Supply Company in 1930. It has been determined to be eligible for listing on the National Register of Historic Places, and formal listing is anticipated following review and approval by the National Park Service (NPS). The building will be rehabilitated in accordance with the Secretary of the Interior\'s Standards for Historic Preservation. Plans are being reviewed by the Arizona State Historic Preservation Office (SHPO). The warehouse will be converted into a commercial office housing about 40 people, and may be the first project in Phoenix to combine LEED-NC certification with the Federal Rehabilitation Tax Credits. Existing brick walls are of double wythe construction, 8 inches in nominal thickness, with original bricks set in a common bond pattern. Consistent with the Secretary of the Interior\'s Standards for Rehabilitation, changes to the building that would alter the historic character, both inside and outside, are not recommended by the SHPO and NPS. Therefore, the addition of insulation to the interior or exterior walls is prohibited since it would alter one of the main "character-defining features" of this building. The ground floor level and surface of the concrete floor are also subject to the constraints of the SHPO/NPS requirements. The only proposed alterations to the building envelope are the addition of storm windows, with insulated glass placed on the interior of the window opening to provide thermal efficiency, and providing insulation to a value of R-30 for a roof that has never been insulated. EAp2 requires this renovation project to comply with ASHRAE 90.1 2004 Sections 5-10 and EAc1 requires that the project secure 2 points, or a 7% improvement over the same ASHRAE standards. While we anticipate meeting the mandatory and prescriptive requirements listed in Sections 6-10, we are unable to meet the requirements in Section 5: Building Envelope. ASHRAE 90.1-2004 Section 4.2.1.3 lists exceptions to compliance with Sections 5-10 for "a building that has been specifically designated as historically significant by the adopting authority or is listed in \'The National Register of Historic Places,\' or has been determined to be eligible for listing by the US Secretary of the Interior need not comply with these requirements." In a Credit Interpretation Ruling dated 5/27/2008, a brick warehouse project similar to this one, also being renovated to meet the Secretary of the Interior\'s standards, and reviewed by the applicable SHPO, and the NPS, was granted permission "to exclude those components that cannot be upgraded to meet the mandatory and prescriptive requirements due to the standards of the Secretary of the Interior and of the National Park Service from demonstrating compliance" in order to comply with LEED Energy and Atmosphere requirements. With this in mind, will this project be allowed to meet EA Prerequisite 2 without securing two points under EAc1, considering that ASHRAE 90.1-2004 exempts the project from meeting the requirements, owing to its historical significance?

The project is a greenhouse-exhibit-office space complex located in urban Denver, CO that serves as a horticulture production facility for the regional botanic gardens. Since the project consists largely of greenhouse space, the project team would like confirmation of baseline assumptions in this process-load dominated space. In addition, modeling limitations exist within the EnergyPlus simulation software for simulating evaporative cooling. The project team would like to confirm acceptance of the analysis method proposed for overcoming the software limitations. Greenhouse Baseline Characteristics In the CIR dated 4/30/2008 concerning energy use in greenhouses, the ruling clearly states that any conditioned space that is used primarily to support plant growth should be modeled as a process space and all characterizations for the space, its space conditioning equipment, and controls should be the same in the baseline and the proposed-design energy model. Therefore, in order to demonstrate efficiency improvements for these end-uses, the project team must follow an exceptional calculation method (ECM) that compares standard design practice to design improvements. The design team desires to demonstrate design improvements in three areas as outlined below. 1) The greenhouse proposed design includes high performance glazing. The project team has found standard design practice for glazing selection for greenhouses to include single-pane clear glass. The team would like to confirm that this is an acceptable baseline for the analysis. 2) The greenhouse design includes an automated shading system to decrease solar heat gain and radiative heat loss in the space. The project team would like to confirm that a greenhouse design without a shading system is an appropriate baseline. 3) The greenhouse design includes an automated natural ventilation system controlled by space and ambient temperature sensors. The ventilation system releases heat from the upper-most portion of the greenhouse when the space temperature exceeds the set-point temperature during mild ambient conditions. The project team believes that automated natural ventilation controls are not part of standard design practice and should be excluded from the baseline greenhouse. The team would like to confirm this baseline condition. Evaporative Cooler Controls Implementation of evaporative cooling systems with EnergyPlus is problematic as active control of evaporative cooling can not occur in conjunction with system or zone heating controls. If there is a need for evaporative cooling, the system operates. Otherwise, the system is off and no heating can be provided at the system or zone level. The EnergyPlus development team has been made aware of these issues but the fix is not foreseen for the near future. This problem results in heating zone loads not being met in the greenhouses. The project team proposes the following solution to work around this evaporative cooling modeling limitation. The solution implemented by the energy analyst is to schedule the evaporative cooling on/off for each hour in the year (8760 schedule), based upon the cooling and heating set points and achieved zone temperatures. Establishing the schedule is an iterative process. However because the evaporative-cooler on-schedule is specified at an hourly time step (and not smaller), the zone temperature for some hours falls below the set point. To minimize these occurrences, the evaporative coolers were shut off when they overcooled the space. But in doing so, this increased the number of hours that loads were not met in the space to be beyond 300 hours. Since this is a process space, the baseline model and proposed design models were treated similarly. Is it acceptable to exceed the 300 hour loads-out-of-range limit due to this simulation software limitation?

The project consists of a consumer products manufacturing facility.The energy intensive manufacturing process exceeds an estimated 90% of the facility\'s total energy load. The Project Client has developed a new manufacturing process which consumes approximately 15% less energy per produced than the previous generation process.The new proprietary process has recently been installed at a similar facility and energy reduction has been demonstrated. Since industrial energy for manufacturing is not covered by ASHRAE 90.1-2007 and the building cannot be accurately modeled using the Appendix G method, project team is seeking to establish and obtain approval of an alternative compliance path.Following the Appendix G procedure would be very challenging because there are so many interacting process and non-process systems. Artificially segregating the systems in the model would not reflect energy consumption patterns accurately. Focusing on non-process components that represent less than 10% of the total energy consumption would not demonstrate the majority of the facility\'s energy savings. Manufacturing process improvements targeted at the other 90% of energy usage have a much greater impact on the entire facility\'s energy consumption. Instead of creating an energy model, baseline and proposed energy consumption will be compared by utilizing an Energy Consumption Index (ECI), which is recognized by the Association of Energy Engineers as an accepted methodology for calculating energy consumption in a manufacturing facility. The Project Client has tabulated historical overall site energy data and production at an existing facility which uses only the previous generation manufacturing platform and is also tabulating data from a site with new generation equipment. The energy data from both of these plants is not sub-metered between process and building loads because there is little economic benefit to meter the small building-only loads. An alternative compliance path will be established using the overall site ECI. Please verify that the following method may be used for determining the entire facility\'s energy cost savings.PROPOSED COMPLIANCE PATH:1. Baseline Building:The existing baseline site

The prerequisites requirements are to design the building project to comply with both- the mandatory provisions (Sections 5.4, 6.4, 7.4, 8.4, 9.4 and 10.4) of ASHRAE/IESNA Standard 90.1-2004 (without amendments); and the prescriptive requirements (Sections 5.5, 6.5, 7.5 and 9.5) or performance requirements (Section 11) of ASHRAE/IESNA Standard 90.1-2004 (without amendments). The project consists on installations for a public park, they are: an exterior amphitheater, one administrative office, exhibition space and a refreshment stand. The project is designed 100% "off-grid" with Photovoltaic (PV) renewable energy source completely, that means that there will be no electrical consumption from fossil fuels. A battery bank will provide the back up power. The project is 100% naturally ventilated. There is no mechanical ventilation and it will be operated accordingly. The ASHRAE\'s Mandatory provisions in Section 5: Building Envelope will not be met completely, outside air infiltration will be promoted, all windows will be opened during operation hours. The walls are designed to be permanently permeable to outside air. Accordingly, thermal transmission will not be possible to achieve in some of the spaces. Section 6: HVAC, will not be contemplated for being outside of the project\'s scope. Section 7: Water heating for service water will be designed with solar thermal water heaters. Therefore water heating in this project is contemplated as no electrical consumption. Section 8, 9 and 10 will be completely contemplated. Because of project\'s scope, complete compliance with ASHRAE would be incoherent. But being a 100% renewable energy, \'off grid\' project, its design is streamlined for energy efficiency, and obliged to operate as intended, as it will be demonstrated. Therefore we think we will meet outstandingly the EA Prerequisite 2 and EA Credit 1 intents, even if deviating from ASHRAE\'s provisions and requirements. Is our assumption correct?

ASHRAE 90.1 does not allow credit for air leakage reduction. However, it does indicate that windows are allowed to have 1 cfm per square foot air leakage (at 0.30" water.) The windows we are using in this project are very high performance, with significantly lower air leakage rates. The manufacturer has supplied test results indicating the tested air leakage rate. Further, we are using a blower door and infra-red camera simultaneously to locate and seal any air leaks in the window system that result from installation. We propose to take credit for this air leakage reduction, with the following methodology:The tested air leakage rate at 0.30" can be established for the windows as installed, based on manufacturer\'s data, and for the base case windows based on ASHRAE 90.1. Both these values will be extrapolated to expected winter heating season air leakage rate, using the LBL correlation for blower door test data. We have run two blower door tests, and will use the most recent (during which most of the air leakage has been taken care of) test data to establish the relationship between the air leakage rate at 0.30" static pressure (75 Pa) and the average heating season air leakage rate, which is calculated at the building pressure established by the LBL correlation, which is based, in part, on the exposure of the building to wind. In this case exposure is significant, as the building is fully exposed on the west side of the building to windows ranging from south to west to north. We then propose to run the base case building, in the energy modeling, using TRACE, with the air leakage rate for the windows established in the above manner. The building as built would be modeled with zero air leakage rate. Preliminary estimates indicate that the difference in overall extrapolate natural air leakage rates in 0.04 air changes per hour, at typical heating season winter conditions. Blower door guided air leakage reduction: A significant effort at air sealing is part of the energy saving strategy for this building. With the location noted above, air leakage reduction is particularly important. Two blower door tests with simultaneous infrared scanning, have been completed. The first identified a number of areas that were not complete as designed. Most of these were completed by the time of the second test, and a number of areas were identified during the second test that, in my opinion, would not have subsequently been air sealed had this procedure not been in place. A list of further items was developed from this second air leakage test, and this list has been circulated by the GC to responsible parties, who will sign off when they have completed the items. When those items are complete, a third, and hopefully final, blower test will be conducted.We propose to take credit in our energy calculations for the air leakage reduction between the second and third blower door tests, using the LBL correlation to extrapolate to typical heating and cooling season air leakage rates, as described in number 2 above. The extrapolated seasonal air leakage rate reduction would be applied to the base case building. For example, if the extrapolated air leakage reduction were 0.1 heating season air changes per hour from blower door test #2 to test #3, we would assign 0.1 ACH to the base case building and zero air leakage to the building as built.We feel that this third round of testing and air leakage reduction is well beyond typical attention paid to air leakage, that air leakage control is particularly important in this very cold (7700 degree-day) climate and at this exposed site, and that we have demonstrated a method using accepted principals to quantify the savings. Blower door test results and LBL correlation spreadsheets for each test would be provided as part of the submission. We would also submit the list of items to be air sealed as part of the final air leakage reduction package. Windows and air leakage reduction together: We propose to add the two air leakage reductions - from window improvements and blower-door-guided air leakage reduction. For example, if the blower-door-guided heating season air leakage rate reduction were 0.1 ACH and the window air leakage reduction were 0.04 ACH, the base case building would be modeled at 0.14 ACH and the building as built at 0.0 ACH.)

The goal of EAp2 is to establish the minimum level of energy efficiency for the proposed building and systems to reduce environmental and economic impacts associated with excessive energy use. Introduction The project is a Core and Shell building in Germany with leasable space for office and retail tenants. The Whole Building Simulation has been prepared in accordance with ANSI/ASHRAE/IESNA Standard 90.1-2007 (ASHRAE 90.1). For larger retail stores, vestibules and revolving doors are unusual entrances for contemporary retail buildings in Germany and would place a disadvantage on the marketability of the tenant spaces. In lieu of vestibules, air curtains are planned for the high traffic entrances to the retail areas to prevent infiltration and improve energy performance. Project Approach The design team would like to propose an alternative compliance path for the Mandatory Provision of ASHRAE 90.1 Section 5.4.3.4 that requires vestibules or revolving doors for entrance spaces greater than 3000 sq ft. This will apply mainly to tenant retail areas. For all entrances requiring vestibules as per ASHRAE 90.1, it is planned to utilize air curtains. Note that the local Codes do not mandate vestibules and they are uncommon for German retail stores. The latest version of the International Green Construction Code, IgCC 2012, approves the use of air curtains as a substitute for the vestibules required by the current International Energy Conservation Code (IECC). Per Section 605.1.2.3 of IgCC, Where a building entrance is required to be protected with a vestibule in accordance with the IECC, an air curtain tested in accordance with ANSI/AMCA 220 is permitted to be used as an alternative to separate conditioned space from the exterior. Air curtains were approved as a substitute for vestibules in the IgCC because they were determined to prevent infiltration and heat loss equally or more effectively than vestibules. The study Air Curtains: A Proven Alternative to Vestibule Design by Berner International utilized computational fluid dynamics (CFD) modeling to demonstrate that air curtains used with automatic doors at building entrances are 10% more energy efficient than vestibules. For entrances with high traffic such as the case for retail, air curtains were calculated to reduce space heat loss by as much as 20-40% compared to standard vestibules. The IECC currently does not include air curtains as an alternative to vestibules, but this measure will be considered by code committees next year. Yet, air curtains are already approved as an acceptable alternative by the IgCC, which can be considered the first step in the approval process for the next version of the IECC. In addition, the USGBC refers to the IgCC as a new code baseline for greener building construction that is complementary to LEED, per USGBC Press Release. Air curtains have been used as an acceptable energy conservation measure to achieve EAc1 points. Approving air curtains as an alternative to vestibules at building entrances meets the intent of EAp2 and ASHRAE 90.1-2007 Section 5.4.3.4, with the added benefit of potentially improved energy performance. Additionally, retail buildings pursuing LEED would not be disadvantaged by losing leasable tenant space or reducing green space as a result of an increased building footprint and by adding further restrictions to building owners trying to find retail tenants in a highly competitive market. For the areas listed in ASHRAE 90.1-2007 Section 5.4.3.4 that would require vestibules, the project team will submit the following: 1. Drawings with locations of air curtains at main entrances 2. Air curtain manufacturer and model number The air curtains will also be commissioned as part of EAp1, Fundamental Commissioning, and EAc3, Enhanced Commissioning, if part of developer scope. Please verify that the above approach is acceptable to satisfy the requirements of LEED-NC/CS 2009 EAp2 for a project in Germany.

We have 108 heat pump PTAC\'s that meet the efficiency requirements of EA prerequisite 2 credit. Due to application requirements, we need to also have 2 vertical heat pump PTAC units. The 2 vertical heat pump PTAC units do not meet the efficiency requirements of EA prerequisite 2 credit. Efficiencies are below: 108 units at EER of 12.8, EA prerequisite 2 requires 11.3 2 units at EER of 9.6, EA prerequisite 2 requires 11.3 The 2 units that don\'t meet the efficiency requirement are similar in capacity to the other 108 units. These units need to be ducted however and they do not offer a ducted unit with the high efficiency option. These units were added to meet building code needs. With only 2 out of 110 total units not meeting efficiency requirements, the average efficiency of the 110 units (all similar in capacity) easily exceeds the minimum requirements. Is it okay to have these 2 units out of 110 total?

Can the baseline model for refrigerated facilities be determined based on the IARW/IACSC Energy Modeling Guideline for Cold Storage and Refrigerated Warehouse Facilities as an exceptional calculation methodology under Appendix G?

There are two main components to this CIR with regards to the prerequisite (envelope / simplified approach with HVAC) detailed as follows: Maximum U-factor and SGHF requirements for the building envelope The majority of the building is naturally ventilated and only the three following areas are being air conditioned:- a) Room 1: Room 1 is air conditioned via an air cooled split package unit system consisting of an outdoor condensing/compressor unit coupled to an indoor air handling unit with a direct expansion cooling coil. The cooled air is distributed to the room via a network of insulated galvanized steel ductwork with ceiling mounted diffusers. b) Room 2: Room 2 is air conditioned via an air cooled variable refrigerant package unit system consisting of an outdoor inverter condensing/compressor unit coupled to a few indoor concealed ducted fan coil units. The cooled air is distributed to the room via a network of insulated galvanized steel ductwork with ceiling mounted diffusers. c) Area 3: The office and meeting rooms are air conditioned via an air cooled variable refrigerant package unit system consisting of an outdoor inverter condensing/compressor unit coupled to a few indoor concealed ducted fan coil units. The cooled air is distributed to the room via a network of insulated galvanized steel ductwork with ceiling mounted diffusers. With regards to the maximum U-factor and SGHF requirements on the building envelope it is suggested we apply only to parts of the envelope separating the air conditioned space with the outdoor space. We also understand there are some requirements for the envelope elements that are adjacent to the \'unconditioned space\' in the Semi-heated column of ASHRAE 90.1-2004 section 5.5.2 and figure 5-5 that we will need to be in compliance with. Simplified Approach Option for HVAC System Instead of complying with the mandatory provision of Section 6.4 of ASHRAE Std 90.1 - 2004, we propose the above mentioned approach based on Section 6.3 of the same standard. The standard allows building with gross floor area less than 2,300 m2 to follow this approach. Although the proposed building gross floor area is approximately 8,300 m2, the air conditioned area in this building is only approximately 1,230 m2. In addition, the proposed air conditioning system as described in Issue 1 (a), (b) and (c) is fairly simple system. Will this suggested building envelope and simplified HVAC System approach be acceptable?

The intent of this credit is to "Establish the minimum level of energy efficiency for the proposed building and systems." The requirements of this credit are as follows: - Comply with the mandatory provisions of ASHRAE Standard 90.1-2004. - Comply with the prescriptive requirements or performance requirements of ASHRAE Standard 90.1-2004. Table 5.5-4 of the Standard, Building Envelope Requirements for Climate Zone 4A: The requirement is as follows: - Fenestration, vertical glazing 40.1-50 % of wall, nonresidential, Ufixed = 0.46, SHGC = 0.25. The exception that we would like to take is as follows: - Field side glazing does not comply with the requirements. Compliant glazing would negatively impact the function of the space. The glazing is there to allow spectator viewing of the ballgame, and its optical and impact properties are of great importance. Single pane, clear glazing must be used in order to provide optimum viewing at all angles, and to provide the required impact resistance. - Since the spaces which have field side glazing are occupied only during a limited number of special events, all Code Authorities throughout the country have allowed us to exclude this component from complying with the published criteria in either the ASHRAE Standard or their own local codes. - We ask that the following values are accepted: U = 1.0, SHGC = 0.75. These performance criteria are typical of ballparks. - We would like to model the baseline building performance and the proposed building performance with the proposed field side fenestration. The project would see neither a positive nor a negative effect on the energy savings.

For buildings with high unregulated energy loads, is it acceptable to show compliance with EA prerequisite: Minimum Energy Performance by considering the unregulated load separately from the ASHRAE 90.1 energy model?

Our project is a multiple building high-end condominium-resort project. This question relates to the requirements of lighting as it pertains to ASHRAE/IESNA 90.1-2004. In ASHRAE 90.1-2004, section 9.1.1, exceptions (b) lists that this section does not apply to lighting within living units. However table 9.5.1 Lighting Power Densities Using the Building Area Method lists "Multi-family" building area type with a 0.7 W/SF. Please clarify for the purposes of EAp2 and EA credit 1, the applicable interpretation of the Standard. Does the entire building have to meet the 0.7W/SF requirement as an average?

The following request is regarding three glass garage roll-up doors that are proposed for this Rescue Station Apparatus Bay. Due to tight site conditions and a shared apparatus exit drive path; it is important safety requirement that glass doors be provided that allow for a line of sight to the adjacent, existing fire station. Exiting dispatched Rescue trucks must have full view of the vehicles in the parking lot and other exiting fire apparatus that both share the common travel pathway. The space is heated and ventilated but not mechanically cooled. This is a garage for the storage of vehicles and will not be heated to the same level as the main building. A total of six 12ft wide by 14ft high, roll-up doors are to be provided; three of the proposed doors, used for entrance, are to be a highly insulated product. In order to provide the required high visibility for the exiting emergency vehicles the three, exit roll-up fire apparatus doors are proposed to be aluminum framed glass doors with a solid bottom panel. No aluminum and glass garage door had been tested to the standards required (NFRC and/or DASMA105) according to review with installers, manufacturers and the Door and Access Systems Manufacturers Association. We are requesting an exemption from the rating requirements for these exit garage doors for the following reasons: 1. Glass doors are required to provide visibility for exiting Rescue Apparatus. 2. No testing data is available for glass roll up doors. 3. The rear doors are highly insulated and we believe the average of all six doors is sufficient to pass the thermal requirements.

This LEED Interpretation pertains to the requirement to limit voltage drop for Energy & Atmosphere Prerequisite 2 for Minimum Energy Performance. The current limit is posing a significant hardship to tall buildings relative to satisfying the mandatory requirements of ASHRAE Standard 90.1-2007 (also applicable in 90.1-2010), referenced in the prerequisite.

Specifically, the requirement in Standard 90.1 to limit voltage drop to not greater that 2% for electrical feeders and 3% for branch circuits (section 8.4.1) has proven to be problematic for large projects which often contain feeders of extended length. By comparison, the National Electric Code does not explicitly regulate voltage drop, but suggests model Code language that limits either electrical feeder or branch circuit voltage drop to 3%, with the combined voltage drop of both feeders and branch circuits when added together not to exceed 5%.

This may appear to be a minor difference, However, when applied to long copper electrical feeders which are present in tall buildings, this absolute constraint from Standard 90.1 on the feeder voltage drop (of 2%) results in a significant increase in the required quantity of copper conductors and associated conduit.

As an example of a higher density regions attempting to resolve this issue, the New York City Electrical Code has adopted the National Electric Code model language as mandatory for all buildings and also included an exception for residential occupancies within buildings to limit electrical feeder voltage drop to 4%, and the combined voltage drop of both feeders and branch circuits to not more than 5%.

This change is in recognition of the inherently short branch circuit lengths in typical NYC apartments, and is based on measured testing results which indicate that voltage drop is often negligible due to the conservative feeder and circuit sizing requirements mandated by other aspects of the Code. Thus, for residential buildings the allowable voltage drop of 4% is twice the allowable voltage drop of 2% as required in 90.1. Depending upon the length and capacity of a particular feeder, this difference can equate to a 3X variance in the required quantity of copper conductors and conduit, with a significant associated cost premium.

The magnitude of the cost premium to satisfy the 90.1 criteria in tall buildings, as compared with New York City Code requirements, can be equal to the total of all of the other cost premiums (hard and soft) associated with achieving LEED certification (at the Silver or Gold level) for a medium to large project in New York City.

In order to resolve this issue, we are proposing an alternate compliance path that we believe would meet the intent of the prerequisite, while at the same time preventing cost prohibitive use of significant amounts of additional copper.

Voltage drop is literally the loss of electrical energy (converted to heat) within a building, therefore regulating voltage drop is no different than regulating the energy efficiency of any electricity consuming device in a building (such as light fixtures or HVAC motors).

Several approaches could be implemented within the LEED rating system to address this disproportionate prescriptive requirement of Standard 90.1. A simple and straight forward approach would be to allow buildings utilizing Appendix G energy modeling as the LEED energy compliance path to include voltage drop as a regulated parameter within both the Energy Cost Budget and Design Energy Cost models. Under this approach, the 90.1 criteria (2% for feeders and 3% for branch circuits) would included in the Energy Cost Budget model, but the Design Energy Cost model would be allowed to include the actual voltage drop that will be implemented in the project design.

This approach would achieve the direct intent of the voltage drop requirement of Standard 90.1 in regulating the energy efficiency of power distribution systems, but through the inherent trade-off methodology of Appendix G would allow projects the flexibility to eliminate a disproportionate cost premium that is otherwise incurred by a prescriptive requirement.

For a data center with 10% office space, verify that exception G3.1.1 (b) from ASHRAE 90.1 can be applied to the server rooms and that server power can be omitted from the model.

The project is a 3,000 square foot 1-story new office building. The requirements of this prerequisite are to comply with the mandatory provisions (sections 5.4, 6.4, 7.4, 8.4, 9.4, and 10.4) of ASHRAE/IESNA Standard 90.1-2004 and the prescriptive requirements (sections 5.5, 6.5, 7.5, and 9.5) of ASHRAE/IESNA Standard 90.1-2004. ASHRAE/IESNA Standard 90.1 2004 Section 8.4.1.1 states "Feeder conductors shall be sized for a maximum voltage drop of 2% at design load." The exception we would like to take is as follows: We meet all the other requirements of this prerequisite for minimum energy efficiency requirements. Our design is approximately a 2.9% voltage drop, which meets the latest edition of the National Electric Code 215-2(A)(2) FPN#2 which allows between 3-5% voltage drop. The cable size is parallel 500 MCM. To meet the 2% requirement, the cable size would be increased to parallel 750 MCM. This is a significant cost increase to the project without gaining any energy savings. Will the 2.9% voltage drop be acceptable to use?

Clarification is requested regarding whether garage demand control ventilation may be modeled for credit. Garage Ventilation is not addressed by ASHRAE 90.1 – 2007, Appendix G, therefore if savings is claimed it must be modeled as an Exceptional Calculation Measure (ECM). Garage demand control ventilation is increasingly becoming standard practice in newly constructed buildings. In order to take credit for this measure as an ECM, it must be demonstrated that the proposed design goes beyond standard practice.

In consideration of EAp2, are plug-in type occupancy sensors acceptable to control task lights?

The applicant is requesting clarification regarding the modeling of a refrigerated warehouse, where refrigeration will comprise the single largest energy end-use in the project. Specifically, the applicant requests verification that the following compliance path is appropriate for a Refrigerated Warehouse building 1. ASHRAE 90.1-2004 lighting requirements will be used 2. Insulation for the Baseline Case Freezers and Loading Dock will be stricter than ASHRAE 90.1-2004, and will comply with ASHRAE Design Essentials, Table 2, p. 50. 3. Refrigeration efficiency measures will be modeled identically in the Baseline and Proposed energy models, and then documented using the Exceptional Calculation Methodology. Most of these measures will use the SBD / Case report as a Baseline, while the remainder of the measures will use Customer’s Standard Practice as the Baseline. The refrigeration energy consumption will be modeled using either an 8,760 hour energy simulation program or a detailed spreadsheet analysis that uses 8,760 weather data, or a combination of the two. The general methodology outlined above is appropriate for this building type, since the entire building will be served by a refrigeration system, and almost none of the building will be served by a standard HVAC system. The following additional requirements will apply for the project EAc1 submittal: Both the budget and proposed design for the refrigerated warehouse should be modeled in an hourly building simulation program (like eQUEST-r), and all efficiency measures that can be documented within the simulation program must be documented using that program. For any efficiency measures that cannot specifically be modeled in the building simulation program, the project may use spreadsheet calculations or other industry software. If spreadsheets are used for documenting energy efficiency measures, sufficient information must be provided to verify that the calculations accurately document the hourly energy consumption of the equipment All exceptional calculations must be thoroughly documented in accordance with the ASHRAE 90.1-2004 exceptional calculation method: the major calculation inputs and assumptions must be clearly documented, and sufficient information must be provided to verify that the calculations accurately document the hourly energy consumption of the equipment. No changes may be made to input parameter values specified by ASHRAE 90.1-2004 Appendix G. For example, occupant sensor lighting controls are allowed a 10% credit per Table G3.2, so no more credit than this may be taken for these controls. Also, no schedule changes can be made to vary the budget from the proposed case unless specifically allowed in Appendix G. Customer’s Standard Practice alone is not sufficient to document the Baseline energy parameters using the exceptional calculation method. The documentation should include sufficient justification to show that the modeled Baseline Case is industry standard practice for new construction of refrigerated warehouses. When referencing a Source (such as the SBD/ Case Report) to document a baseline case parameter or to document the validity of a proposed efficiency measure, please include excerpts of the source to verify that the referenced method is being used.

Our project is subject to ASHRAE Standard 90.1-2013 for code compliance. To pursue Option 1: Whole Building Simulation, is there a methodology for documenting additional energy performance for LEED v4 projects regulated by ASHRAE Standard 90.1-2013?

As 90.1-2007 is essentially a compilation of addenda, we assume it may be treated in the way outlined in the footnote to EA prerequisite 2, "Project teams wishing to use ASHRAE approved addenda for the purposes of this credit may do so at their discretion. Addenda must be applied consistently across all LEED credits." However, between 2004 and 2007 Appendix G was modified in some ways without addenda being published or approved, and these modifications were made official only by inclusion in the 2007 version. We further assume that we can use these modifications, as long as we use ALL the modifications in the 2007 Appendix G and referenced sections of 90.1, similar to the guidance on addenda noted above. Is this correct?

Energy & Atmosphere, Prerequisite 2.0 Minimum Energy Performance. More specifically, we need an interpretation of 2004 Ashrae 90.1 Standard Section 9.6.1 on whether or not we are allowed to trade interior lighting power allowances between spaces in different buildings when the buildings are on the same tract of land and operated by the same owner. Our interpretation of the 2004 Ashrae 90.1 Standard Section 9.6.1 is that we can trade interior lighting power allowances between spaces in different buildings when using the Space-by-Space Method of Calculating Interior Lighting Power Allowance for this project. This interpretation arises from the fact that we have multiple buildings on the same tract of land that will be operated by the same entity, the Federal Government. If we can make this interpretation, we can meet the Standard. If not, some buildings on their own will not meet the Standard.

ASHRAE 90.1-2019 recently published an Exception to G1.2.2 that permits energy used to recharge or refuel vehicles that are used for off-building site transportation purposes to be excluded from the building performance model. Can we apply this exception to our LEED D+C project, when using an earlier version of ASHRAE 90.1 Appendix G?