NC-2009 EAp2: Minimum Energy Performance Required

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.

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?

For a fine art museum pursuing EAp2, is it acceptable to use the systems and recommendations described in the ASHRAE HVAC Applications 2007 Handbook as the baseline in cases where Appendix G does not adequately describe a typical preservation area?

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?

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?

We have a technical question regarding an energy model for a project that is a 450,000 sq. ft. warehouse plus 30,000 sq. ft. of office space. The warehouse is conditioned by (6) gas fired constant volume 80/20 units. In addition, the warehouse contains 6 constant volume ventilation fans with low outdoor air dampers utilized in the summer to provide air movement when the temperature is above 80 degrees. According to ASHRAE 90.1 Appendix G we will need to provide heating and COOLING to this space in both the baseline and proposed with the cooling system type and parameters being equal in the proposed and baseline. We have been discussing internally what the correct path for modeling this type of system should be and believe we are at a point where we need guidance from a higher authority on the correct path. The following are different options we have discussed and the issues we see with each:Model the baseline and proposed cooling system the same as both baseline and proposed (System 7) - Issue - the system 7 calls for a VAV reheat system. This would mean the proposed design would have VAV fans for cooling and heating. We feel this is inaccurate due to the fact the proposed design actually includes constant volume fans for heating. Model the proposed system as constant volume heating but VAV cooling - Issue - Again we have constant volume ventilation fans in the summer and have no way of accounting for their energy usage. If we set them up as an extra utility then we are being charged on both using a VAV fan in the system as well as the constant volume fan in the summer. Essentially using twice the fan power than what is designed.Model proposed as being constant volume all year and the baseline being VAV - Issue- the proposed is now at a big disadvantage for mechanical cooling at constant volume when we don\'t have mechanical cooling in the proposed design any way. Also, now the proposed and baseline cases are not held equal in the cooling season. Also, how would we model the ventilation? Are we to assume that we are now 100% outdoor air with a constant volume fan? This would put us at a big disadvantage against ASHRAE 90.1 requirements. Another issue we are finding with all these scenarios is that we are inflating the resulting energy cost such that no savings can be realized by using a better envelope, better equipment, and reduced lighting power. Furthermore, the horsepower for the proposed ventilation fans is low due to minimal resistance in airflow (no ductwork, no coils, no filters, etc). Assuming we model these as you would a typical supply fan, the baseline system would need to follow the Appendix G calculation for allowable horsepower, and therefore the baseline horsepower would be greatly inflated compared to the proposed design. This would create an advantage for the proposed design that is inaccurate.ASHRAE 90.1 2010 specifically covers this type of building. In the 2010 version, Appendix G has added two additional systems and provided the additional information to complete an ASHRAE 90.1 comparison for a heating only and ventilating system. When modeling after the 90.1 2010 protocol the results seemed to fall in line with where we would have expected them to be. The modeling protocol made it possible to show energy savings due to lighting, envelope, and more efficient equipment while not creating either advantages/disadvantages in the modeling technique. Would it be acceptable to the USGBC to model after the 2010 version of ASHRAE 90.1 and provide a narrative describing why we used the 2010 version to complete the analysis?

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?

This project involves the construction of a new refrigerated freezer warehouse. The overall facility is 140,000 sf. 105,000 sf is a -10 degree F freezer space, and the remaining area a +45 degree F freezer truck dock. There is a small office area, as well as support and maintenance areas. The facility operates as a distribution warehouse. Shipping and receiving logistical staff occupy the building. An automated material handling system means no people are in the freezer portion of the building. The facility is staffed 10 hours per day, 5 days per week; the refrigeration systems run continuously. A CIR was submitted on January 4, 2008, and responded to on February 4, 2008 for an earlier project being planned by the same building owner. This CIR builds on the previous response, and also raises some new questions. In the previous CIR, we defined a set of baseline parameters for areas not covered by 90.1 and indicated sources that support these assumptions. The reviewer requested specific documentation regarding baseline parameters and “industry standard practice”. Baseline Design In the previous CIR, the choice of refrigerant, compressor type, and capacity control method were based on “Customer’s Standard Practice”. The reviewer asked for more justification. Please confirm that the following will be acceptable. Refrigerant The baseline refrigerant in the previous CIR was R-22, although ammonia may be more widespread in facilities this size. However, the densely populated location and the local codes at the new site would require 24/7 certified ammonia operators. As the building will be staffed 10 hours, M-F, a 24/7 operator is not viable. The proposed building will use R-22 for these reasons. Can an R-22 system be the baseline? We will provide copies of the appropriate local regulations or other documentation to support this baseline assumption. Compressor Type and Capacity Control We are requesting confirmation that a letter from the refrigeration contractor stating that the customer’s choice of single stage rotary screw compressors with slide valve control to be industry standard practice is acceptable documentation. Automation within the Warehouse One of the most innovative aspects of the facility’s proposed design is fully automated material handling in the freezer. All the customer’s other facilities use regular forklifts. The automated material handling system provides energy benefits including reduced plug and infiltration loads. The greatest impact, though, is that the warehouse will be dark unless maintenance or repairs are required. We are requesting confirmation that it is acceptable to use a baseline that assumes human-driven forklifts, and that the warehouse would be equipped with fixtures that have a lighting power density according to AHSRAE 90.1 and operate on a schedule that is defined by usage of the warehouse. The proposed case energy model would be based on “lights out” operation. This saves refrigeration energy as well as lighting energy. In the office space, we will model occupancy sensors based on the 10% reduction in Appendix G Table 3.2. In the freezer truck dock, we will model the lighting as being controlled by an identical schedule in both the baseline and proposed designs. However, we are contending that a completely automated warehouse goes beyond occupancy sensor control, and are requesting confirmation that we are not limited to the 10% lighting reduction described in Table 3.2. Documentation will support the baseline assumption of an occupied, lighted freezer, and also show that the equipment in the proposed design will operate without the regular use of lighting fixtures.

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.

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?

We would like clarification as to whether EA p2 can be demonstrated and EA credit 1 points achieved based on centrally managed lighting wattage limits. Specifically, we would like to know if the wattage limits set by the DALI (Digital Addressable Lighting Interface) system, which allows maximum wattage limits to be programmed into all fixtures, can be used to show credit compliance. Our project, the fit-out of an office space, would like to utilize these controls in order to provide exceptional energy efficiency, individual occupant control including individual fixture dimming in the open office space, as well as to control these lamps with IR occupancy sensors, photo sensors, and programmable time clocks for additional energy savings. The system also includes facility maintenance reporting of lamp and ballast status and energy usage monitoring and trend logging and could include demand response interface with BMS if desired, though not part of this project. While setting the maximum allowable wattage on the DALI system absolutely limits the amount of wattage able to be drawn by the fixtures and this limit is not something that can be over-ridden by building occupants, it is not clear if computer based controls are allowed by ASHRAE 90.1 or the LEED Rating System. It is standard practice for LEED projects to utilize reduced ballast factors or physical wattage limiters as a means to claim energy efficiency from a fixture. The dimmable DALI system and efficient T-5 linear fluorescent lamps proposed by our project cannot utilize fluorescent ballasts with a reduced ballast factor, but the equivalent energy savings can be seen by capping the fixture wattage when setting up the space\'s lighting controls. The alternative to this approach would be to utilize fewer fixtures and produce more light from each, but then the individual workstation controllability provided by the DALI system is negated because individual fixtures are shared by multiple workstations. We would like verification that it is OK to use the maximum allowable wattage set in the DALI system to compare to the AHSRAE lighting power density. The building owner will provide a signed note stating that the wattage limits will not be altered (and won\'t need to be as the lighting levels are designed to be completely sufficient with the 70% wattage limits proposed). This is consistent with the LEED Core and Shell energy modeling requirements that allow reduced lighting power densities if included in the lease agreement (a written confirmation that these levels will be met). Consistent with ASHRAE and the LEED Reference Guides, we will assume the highest wattage lamps acceptable in the fixtures and follow all other ASHRAE guidelines.

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.

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.

Background: This project is using underfloor air distribution (UFAD) as the main HVAC system. Passive floor-mounted swirl-type diffusers (manually operated by the occupants for interior "cooling-only" zones. They will not be controlled via thermostats. The perimeter zones will be served by UFAD fan powered units (with electric heat for heating) and will be controlled via space mounted thermostats. The prerequisite requires compliance with ASHRAE 90.1-2004, section 6.4. Section 6.4.3.1.1 states: "The supply of heating and cooling energy to each zone shall be individually controlled by thermostatic controls responding to temperature within the zone". Question: Does the use of passive floor mounted diffusers in the UFAD system and controlled as described above meet the requirements of ASHRAE 90.1-2004, section 6.4.3.1.1 and this prerequisite?

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?

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.

The tenant\'s fitout design complies with most of the requirements of EA P2 however due to local design standards and the clients operational process requirements there are 2 clauses that we are not able to achieve and as such will require a waiver for : ASHRAE 90-1 2004 Clause 6.5.4 Hydronic System Design and Control As part of the Client\'s global network the fitout for the above project includes a data centre/ main communications room (MCR). The cooling load associated with the MCR is served by a number of chilled water units connected to 2no tenant packaged air cooled chiller. Due to the constant nature of the process load associated with the MCR room it is not proposed to install Variable speed drives to the pumps. The heat load associated with the servers contained within the MCR room is maintained at close to 100% due to the international nature of the network that the system serves and as such it is operated 24/7. The introduction of Variable Speed pumping to this system (as required to comply with ASHRAE 90.1 -2004 clause (6.5.4.1 Hydronic Variable Flow Systems) would therefore not achieve any energy saving and as such is not proposed to be installed. The client is willing to install them if necessary however does not understand how the procurement, manufacture, installation and maintenance issues associated with the additional equipment increases the sustainability of the project, given the very limited scope for VSDs to reduce energy use. Furthermore the additional complexity of Variable Speed Drives within such a critical process system adds further risk to the client business. ASHRAE 90.1-2004 allows exemption to clause 6.5.4.1 where a reduced "flow is less than the minimum flow required by the equipment manufacturer for the proper operation of the equipment served by the system" we believe that we qualify for this exemption as the client\'s critical system would be affected by any reduction in chilled water flow. As such it is proposed to install the pumps as a constant volume system albeit fitted with high efficiency motors which when combined with high efficiency air cooled chillers which exceed the minimum set out in ASHRAE 90.1-2004 (table 6.8.1C) produce an energy efficient solution which does not compromise the clients operational requirements. Further to this the application of temperature reset on the chilled water system (clause 6.5.4.3) would also be detrimental to the clients critical systems as such we believe that the system is exempt under the relevant exemption clause within the standard. ASHRAE 90-1 2004 Clause 8.4.1 Voltage Drop The local design standards require the voltage drop across the system to be sized as a maximum of 4% with 3.5% being from the feeder conductors and 0.5% from the branch circuits. The ASHRAE standard calls for a maximum voltage drop at design of 5% with 2% being from the feeder conductors and 3% from the branch circuits. As such the local design standard calls for a smaller voltage drop across the system, relative to the ASHRAE standard, but with a different split between sections. The project is therefore looking for a credit interpretation regarding this issue on the basis of the local design standards being lower on a total system basis, albeit with a different percentage split across the system.

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?

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"?

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?

Our project is located in California. To pursue Option 1: Whole Building Simulation, is there a methodology for documenting additional energy performance for LEED v4 projects regulated by Title 24-2016 or later?

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

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.)