NC-v4 EAp2: Minimum energy performance

  • A high bar, but still achievable

    This prerequisite is a big one, not only because it’s required for all projects, but also because it feeds directly into EAc2: Optimize Energy Performance, where about a fifth of the total available points in LEED are at stake.

    From the beginning, teams should recognize that the baseline requirements are fairly stringent. Some measures that may have previously contributed to design-case efficiency are now being required just to meet this prerequisite.

    Key updates with ASHRAE 90.1

    ASHRAE 90.1-2010 has introduced a number of new requirements compared to the 2007 standard, including increased efficiencies requirements for envelope, HVAC equipment and lighting; enhanced interior lighting control requirements (occupancy sensors, light level reduction and daylight controls); new exterior lighting and parking garage lighting control requirements; and new automatic shut-off requirements for 50% of receptacles in offices and computer classrooms.

    With these changes, however, comes a helpful update to the prerequisite documentation that will make the review process go more smoothly for both project teams and GBCIThe Green Building Certification Institute (GBCI) manages Leadership in Energy and Environmental Design (LEED) building certification and professional accreditation processes. It was established in 2008 with support from the U.S. Green Building Council (USGBC). reviewers. An updated Energy Performance Calculator is required documentation for your LEED submittal.

    It performs a series of self-checks in the background to flag potential issues, allows the energy modeler to do a step-by-step quality assurance review, and maybe most importantly helps the reviewer to better understand the model, all of which should significantly reduce the quantity of back-and-forth comments and responses required between the modeler and GBCI reviewer. Read more about the calculator, including an overview of how to use it, here on LEEDuser.

    What’s New in LEED v4

    • ASHRAE 90.1-2007 has been updated to ASHRAE 90.1-2010.
    • Process energy no longer has to make up 25% of the overall building energy for your baseline and proposed simulation models.
    • USGBC now requires you to achieve prerequisite compliance without accounting for the cost of generating renewable energy onsite.
    • For data centers, USGBC requires that building power and cooling infrastructure provides 2% of the required 5% energy cost reductions.
    • For Option 2, LEED now includes a prerequisite that the standard for compliance uses the 50% savings version of the AEDG instead of the 30% savings version of the AEDG. This represents an expected savings of 50% over ASHRAE 90.1–2004.
    • To achieve the prerequisites for Options 2 and 3, your project must follow ASHRAE 90.1–2010 mandatory and prescriptive requirements.

    FAQs

    Our proposed design has insulation R-values that are below those prescribed by ASHRAE 90.1-2010. Can we still meet the prerequisite?

    Yes, the R-value of the building envelope is not mandatory. You can install lower R-values. You are only required to meet the mandatory provisions and earn the minimum percent savings.

    Do the required savings for this prerequisite (and credit) need to come only from building energy, or also process loads?

    The energy savings are based on the whole building energy use—building and process. LEED does not stipulate exactly where they come from, but there is a greater burden of proof on the project team to demonstrate savings in process energy. As a default, process energy should be modeled the same in both baseline and design case.

    Our project doesn't have enough energy savings to earn the prerequisite. Can we get there by incorporating onsite renewables?

    No. The energy cost offset from onsite renewable energy sources can no longer be used to earn the prerequisite. Additionally, it is usually more cost-effective to invest in energy savings in the building.

     

  • EA Prerequisite 2: Minimum energy performance

    Intent

    To reduce the environmental and economic harms of excessive energy use by achieving a minimum level of energy efficiency for the building and its systems.

    Requirements

    Option 1. Whole-building energy simulation

    Demonstrate an improvement of 5% for new construction, 3% for major renovations, or 2% for core and shell projects in the proposed building performance rating compared with the baseline building performanceThe annual energy cost for a building design, used as a baseline for comparison with above-standard design. rating. Calculate the baseline building performance according to ANSI/ASHRAE/IESNA Standard 90.1–2010, Appendix G, with errata (or a USGBC-approved equivalent standard for projects outside the U.S.), using a simulation model.

    Projects must meet the minimum percentage savings before taking credit for renewable energy systems.

    The proposed design must meet the following criteria:

    Document the energy modeling input assumptions for unregulated loads. Unregulated loads should be modeled accurately to reflect the actual expected energy consumption of the building.

    If unregulated loads are not identical for both the baseline and the proposed building performance rating, and the simulation program cannot accurately model the savings, follow the exceptional calculation method (ANSI/ASHRAE/IESNA Standard 90.1–2010, G2.5). Alternatively, use the COMNET Modeling Guidelines and Procedures to document measures that reduce unregulated loads.

    OR

    Option 2. Prescriptive compliance: ASHRAE 50% Advanced Energy Design Guide

    Comply with the mandatory and prescriptive provisions of ANSI/ASHRAE/IESNA Standard 90.1–2010, with errata (or a USGBC-approved equivalent standard for projects outside the U.S.).

    Comply with the HVAC and service water heating requirements, including equipment efficiency, economizers, ventilation, and ducts and dampers, in Chapter 4, Design Strategies and Recommendations by Climate ZoneOne of five climatically distinct areas, defined by long-term weather conditions which affect the heating and cooling loads in buildings. The zones were determined according to the 45-year average (1931-1975) of the annual heating and cooling degree-days (base 65 degrees Fahrenheit). An individual building was assigned to a climate zone according to the 45-year average annual degree-days for its National Oceanic and Atmospheric Administration (NOAA) Division., for the appropriate ASHRAE 50% Advanced Energy Design Guide and climate zone:

    • ASHRAE 50% Advanced Energy Design Guide for Small to Medium Office Buildings, for office buildings smaller than 100,000 square feet (9 290 square meters);
    • ASHRAE 50% Advanced Energy Design Guide for Medium to Large Box Retail Buildings, for retail buildings with 20,000 to 100,000 square feet (1 860 to 9 290 square meters);
    • ASHRAE 50% Advanced Energy Design Guide for K–12 School Buildings; or
    • ASHRAE 50% Advanced Energy Design Guide for Large Hospitals. Over 100,000 square feet (9 290 square meters)

    For projects outside the U.S., consult ASHRAE/ASHRAE/IESNA Standard 90.1–2010, Appendixes B and D, to determine the appropriate climate zone.

    OR

    Option 3. Prescriptive compliance: Advanced BuildingsTM Core PerformanceTM Guide

    Comply with the mandatory and prescriptive provisions of ANSI/ASHRAE/IESNA Standard 90.1-2010, with errata (or USGBC approved equivalent standard for projects outside the U.S.).

    Comply with Section 1: Design Process Strategies, Section 2: Core Performance Requirements, and the following three strategies from Section 3: Enhanced Performance Strategies, as applicable. Where standards conflict, follow the more stringent of the two. For projects outside the U.S., consult ANSI/ASHRAE/IESNA Standard 90.1-2010, Appendixes B and D, to determine the appropriate climate zone.

    3.5 Supply Air Temperature Reset (VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas.)

    3.9 Premium Economizer Performance

    3.10 Variable Speed Control

    To be eligible for Option 3, the project must be less than 100,000 square feet (9 290 square meters).

    Note: Healthcare, Warehouse or Laboratory projects are ineligible for Option 3.

    Pilot ACPs Available

    The following pilot alternative compliance paths are available for this prerequisite. See the pilot credit library for more information.

    EApc92: Advanced Buildings™ New Construction Guide
    EApc95: Alternative Energy Performance Metric
    EApc107: Energy Performance Metering Path

    Alternative Compliance Paths (ACPs)

    Canada ACP - NECB

    Projects in Canada may instead demonstrate a percentage improvement in the proposed building performance rating compared with the baseline according to the National Energy Code for Buildings (NECB) 2011. The same percentage cost improvement in energy performance is required to meet the Prerequisite, and the same points for cost percentage improvement in energy performance are applicable for the Credit.

    The following conditions (where applicable) must be met. Note that unless otherwise noted, CanQUEST (the Canadian energy modelling software based on eQUEST that performs NECB 2011 compliance runs) does not implement many of these conditions correctly and would require corresponding modifications to the Reference case.

    1. Comply with mandatory requirements of ASHRAE 90.1-2010
    2. ASHRAE 90.1-2010 mandatory requirements must be met, in addition to the performance path limitations referenced in the NECB 2011 Sections 3.4.1.2, 5.4.1.2 and 6.4.1.2. In cases where ASHRAE and the NECBC reference requirements concerning the same item, the more stringent requirement shall be adhered to.

      The following exceptions apply:

    • ASHRAE 90.1-2010 mandatory items 6.4.3.9, 9.4.1.2b, 9.4.1.4, 9.4.1.5, 9.4.3

  • Apply fenestration area convention similar to ASHRAE 90.1-2010
  • Maintain the same FWR (as defined by NECB, including doors) for the Reference as exists in the Proposed Design, up to the prescribed maximum. If the Proposed Design’s FWR exceeds the prescribed FWR, scale down the fenestrations in the Reference case accordingly.

  • Apply skylight area convention similar to ASHRAE 90.1-2010
  • Maintain the same SRR for the Reference as exists in the Proposed Design, up to the prescribed 5% maximum. If the Proposed Design’s SRR exceeds 5%, scale down the skylights in the Reference case accordingly.

  • Model proposed and reference outside air similar to ASHRAE 90.1-2010
  • Proposed and reference (baseline) outside air rates shall be modeled as per ASHRAE 90.1 – 2010 (G3.1.2.6).

  • Apply ASHRAE kitchen exhaust demand ventilation requirements
  • Provide for the same demand ventilation requirements as described in ASHRAE Appendix G3.1.1.d.

  • Apply ASHRAE’s chiller heat recovery requirements
  • Provide for the same chiller heat recovery requirements as applies to ASHRAE.

  • Apply supply air temperature reset controlled based on warmest zone
  • Reset the minimum supply air temperature to satisfy the cooling requirements of the warmest zone, as stipulated in NECB Section 5.2.8.8. Note that this control setting is already corrected in CanQUEST for the Reference case.

  • Account for uninsulated structural penetrations if they exceed 2% of net wall area
  • The 2% allowance may be applied, but based on the net opaque wall area, not the entire building envelope area.

  • Follow ASHRAE/LEED rules for renovations to existing buildings
  • Model existing components consistent with ASHRAE and LEED provisions.

  • Account for all anticipated energy use in building
  • Fully account for all energy end-uses in the energy performance modelling.

  • DES Systems are to be modeled according to Option 1, Path 1 or Option 1, Path 2 as indicated in the LEED v4 Reference Guide
  • The following exceptions apply:

    • Option 1, Path 1 - Do not apply ASHRAE 90.1-2010 requirements for purchased heating and cooling. Under this ACP, purchased heating and cooling (as applicable) are modeled as cost-neutral in the baseline and proposed case. Local rates for purchased heating (fossil fuel based) and cooling are used to establish the purchased heating and cooling costs. The energy model's scope accounts for only downstream equipmentThe heating and cooling systems, equipment, and controls located in the project building or on the project site and associated with transporting the thermal energy of the district energy system (DES) into heated and cooled spaces. Downstream equipment includes the thermal connection or interface with the DES, secondary distribution systems in the building, and terminal units. Drift water droplets carried from a cooling tower or evaporative condenser by a stream of air passing through the system. Drift eliminators capture these droplets and return them to the reservoir at the bottom of the cooling tower or evaporative condenser for recirculation., plus purchased heating and cooling. NECB clause 8.4.3.6 does not apply for LEED projects.
    • Model baseline systems in accordance with NECB requirements, with DX coils replaced with chilled water coils if purchased cooling is present and fossil-fired furnaces replaced with hot water coils if purchased heating is present.
    • Option 1, Path 2: Do not apply ASHRAE 90.1-2010 requirements for baseline systems. Model baseline systems in accordance with NECB requirements for onsite generated equipment (i.e. assume building is not connected to a DES and the proposed building is modeled with a virtual plant according to LEED v4 Reference Guide requirements).

168 Comments

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K Nakamura
Mar 14 2017
LEEDuser Member
99 Thumbs Up

Elementary School

Project Location: United States

Is there any special considerations for a project registered (v2.2) and designed 10 years ago is now being constructed. V2.2 and v2009 have expired so we need to register it for v4. However, since it was designed to ASHRAE 90.1-2004, it does not comply with ASHREE 90.1-2010.

Thank you.

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Marcus Sheffer LEED Fellow, 7group Mar 15 2017 LEEDuser Expert 69162 Thumbs Up

Does it comply with 90.1-2007?

Probably your only option would be to upgrade your registration to LEED 2009. If the project was registered already you should be able to transfer the registration. I would think USGBC would let you. It can't hurt to ask.

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Mark Benson
Mar 10 2017
Guest
397 Thumbs Up

Using different energy rates between CHP Proposed and Baseline

Project Location: United States

I know that the 90.1 and the LEED Reference Guide generally tell you to use the same utility rate structures for both the Proposed and Baseline models. But what happens when the Proposed model uses Full Accounting of DESDistrict energy system: a central energy conversion plant and transmission and distribution system that provides thermal energy to a group of buildings (e.g., a central cooling plant on a university campus). It does not include central energy systems that provide only electricity. and includes DES-CHPCombined heat and power (CHP), or cogeneration, generates both electrical power and thermal energy from a single fuel source.-supplied electricity and steam, while the Baseline uses On-site Boilers and grid-tied electricity? The DES is charged $0.45/therm while a new gas service at the Baseline Project Building would be charged $0.73/therm due to inherently different rate structures).

I've provided a link below to a CHP LEED Calculator (provided by the EPA CHP Partnership) which instructs the user to use $0.45/therm in the Proposed model since it is a special price for CHP gas and $0.73/therm in my Baseline model (See Inputs tab, rows 14 and 17). Is this acceptable from a USGBC perspective? Thanks!

http://epa.gov/chp/documents/chp_leed_calculator.xlsm

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Marcus Sheffer LEED Fellow, 7group Mar 13 2017 LEEDuser Expert 69162 Thumbs Up

The rates must be identical for LEED. The Baseline system in this case is a virtual DESDistrict energy system: a central energy conversion plant and transmission and distribution system that provides thermal energy to a group of buildings (e.g., a central cooling plant on a university campus). It does not include central energy systems that provide only electricity. so it must use the same rate as the Proposed case.

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R2M Solution Srl R2M Solution Srl
Mar 07 2017
LEEDuser Member
214 Thumbs Up

Treatment of District or Campus Thermal Energy in LEED v4

Project Location: Italy

Can the document "Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 – Design & Construction" be used also for LEED v.4? Any news about an updated version of that document?
Best Regards

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Marcus Sheffer LEED Fellow, 7group Mar 07 2017 LEEDuser Expert 69162 Thumbs Up

The v4 version of this document is now embedded in the LEED v4 Reference Guide.

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R2M Solution Srl R2M Solution Srl Mar 07 2017 LEEDuser Member 214 Thumbs Up

Thank you. It seems that there is no more the points cap for the simplified option that there was in the document "Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 – Design & Construction" (10 points for Table 1).
Correct?

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Jim Quillin Mechanical Engineer, Henderson Engineers Mar 20 2017 Guest

I am also interested in this topic and its answer.

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Marcus Sheffer LEED Fellow, 7group Mar 21 2017 LEEDuser Expert 69162 Thumbs Up

Correct. The point cap and floor are not longer part of the DESDistrict energy system: a central energy conversion plant and transmission and distribution system that provides thermal energy to a group of buildings (e.g., a central cooling plant on a university campus). It does not include central energy systems that provide only electricity. guidance.

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André Harms Ecolution Consulting
Feb 21 2017
LEEDuser Member
212 Thumbs Up

Motor efficiency in 50Hz countries

Project Location: South Africa

In response to the ASHRAE 90.1:2007 mandatory requirements for the efficiency of 60Hz motors, some had used the European IE2 standard for 50Hz motors and demonstrated equivalency. The ASHRAE 90.1:2010 standard and user manual have however clarified that all 50Hz motors are exempt. The user manual states that the motor types that are exempted are due to the fact that they “serve a special purpose”, are “not appropriate for …” and “not common in … general building systems” or “have a small energy impact”. This is obviously not true in a country where nearly all motors are 50Hz, but they seem clear on the matter. Whilst we support and would advocate for the use of higher efficiency motors on projects, it seems like high-efficiency motors are no longer (or never were) a mandatory requirement we can enforce? For context, IE1 motors are the current minimum requirement in South Africa, although the implementation of the IEC standard is intended in the future.

If all the 50Hz electrical motors on a project are indeed exempted from the mandatory efficiency requirements, how would this be reflected in the modelling? In ASHRAE 90.1-2007, Table G3.1-'Modelling Requirements, sub-section 12 – Receptacle and Other Loads' states that "where no efficiency requirements exist……equipment" (incl. motors covered by section 10) "…shall be identical b/w the baseline and proposed…”. Would this clause be applicable in the case of a project where 50Hz motor is exempted for the reasons stated above? Or, the lowest efficiency for the 60 Hz electric motor as specified under Tabled 10.8B of Section 10 will be considered for baseline modelling whereas, the proposed will be as per the actual design?

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Jean Marais b.i.g. Bechtold DesignBuilder Expert Feb 21 2017 LEEDuser Member 11003 Thumbs Up

"the proposed will be as per the actual design" Yes.
Because the standard does not have a minimum efficiency for 50Hz motors, they are UNREGULATED and therefore modeled the same as the design.
Although that is a huge oversight by the 90.1 commitee!

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Marcus Sheffer LEED Fellow, 7group Feb 21 2017 LEEDuser Expert 69162 Thumbs Up

I would check the newer versions of 90.1 to see if this has been addressed. If not perhaps an ASHRAE Interpretation is in order.

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John Krutko Sr Project Manager Osborn Engineering
Dec 19 2016
LEEDuser Member
24 Thumbs Up

Updates Differences Between 90.1-2007 and 90.1-2010

Does anyone have a link to a concise list of the differences between 90.1-2007 and 90.1-2010?

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Marcus Sheffer LEED Fellow, 7group Dec 22 2016 LEEDuser Expert 69162 Thumbs Up

If you search - comparison of 90.1-2007 to 90.1-2010 - you get some links to summaries of the changes.

The Department of Energy does a study on the difference in relative stringency of the various versions of the standard which you can get from https://www.energycodes.gov/

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Jean Marais b.i.g. Bechtold DesignBuilder Expert
Dec 14 2016
LEEDuser Member
11003 Thumbs Up

Thank you USGBC for Energy Performance Calculator

Thank you USGBC for Energy Performance Calculator. I remember the days before...where you had to make your own more or less whilst fumbling through projects. I've not tested this, but it looks fantastic. A road map.

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Amrit Kaur Association for Energy Affordability
Dec 05 2016
LEEDuser Member
11 Thumbs Up

Code is surpassing 90.1-2010

In a Jurisdiction where code is surpassing ASHRAE 90.1-2010 LEED buildings are required (by code) to meet the more stringent requirements but measure their energy score based improvement from ASHRAE 90.1-2010 is that correct ? or would the baseline be code requirement ? (There used to be a clause establishing the latter in LEED v2 but in V4 it is not there)

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Marcus Sheffer LEED Fellow, 7group Dec 05 2016 LEEDuser Expert 69162 Thumbs Up

You are correct. Projects in states with more stringent codes start out ahead of states with less stringent codes.

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Carol SR
Nov 30 2016
Guest
4 Thumbs Up

Baseline HVAC System Type - for laboratories

Project Location: Portugal

Hello!

I am constructing a building model which spaces are half offices, half laboratories.
The HVAC system chosen is system 5 (packaged VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. with reheat) for all building, since it is considered a single thermal block.
In order to meet G3.1.1 c., is it necessary to model laboratories area itself with an independent system 5 or 7? Or should I model the entire building with a single HVAC (system 5)?

Thanks

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Marcus Sheffer LEED Fellow, 7group Nov 30 2016 LEEDuser Expert 69162 Thumbs Up

Any applicable exceptions to G3.1.1 must be included in the baseline model.

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Robyn Dowsey Owner Eco-Build Strategies LLC
Nov 28 2016
LEEDuser Member
163 Thumbs Up

EA - Pre-Conditioned Air

Project Location: United States

Has anyone used Pre-Conditioned Air to support energy savings or IN credit compliance?

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Marcus Sheffer LEED Fellow, 7group Nov 28 2016 LEEDuser Expert 69162 Thumbs Up

G3.1.2.4 requires a preheat coil in the baseline if there is one in the proposed.

How are you preconditioning the incoming air?

IN?

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Robyn Dowsey Owner, Eco-Build Strategies LLC Nov 29 2016 LEEDuser Member 163 Thumbs Up

Innovation
Preconditioned Air (PCA) Systems:
Preconditioned Air (PCA) systems provide for cooling of the aircraft cabin while parked at the
gate, and can offer PBB cooling. Alternatives for providing PCA include mobile ground based
units, Central Plant systems (with or without thermal storage), and Point of Use (POU) Systems.
Central plant systems typically are the most efficient over the facility life cycle, and providing
thermal storage can significantly reduce chiller size and energy consumption, although they have
a higher capital cost and greater interior space requirements. Central plant systems distribute a
glycol water solution to air handling units mounted directly on each PBB. POU systems utilize
self-contained direct expansion (DX) refrigeration package units that also mount directly to the
PBB. POU systems typically have the lowest initial capital costs, but highest long term
operation and maintenance costs. Mobile PCA units are typically only used at remote parking
positions, or on a temporary basis in the event of an equipment failure at gate.

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Robyn Dowsey Owner, Eco-Build Strategies LLC Nov 29 2016 LEEDuser Member 163 Thumbs Up

The Central PCA design provides an opportunity to significantly lower energy use and operating
costs. Since PCA is considered “process equipment” and not part of the comfort cooling HVAC
for the building, it is exempt from the Energy Compliance defined in the Florida Energy Code and
ASHRAE 90.1-2010. We highly recommend that the base buildingThe base building includes elements such as the structure, envelope, and building-level mechanical systems, such as central HVAC, and materials and products installed in the project (e.g., flooring, casework, wall coverings). design team consider
submitting exceptional calculations for the energy savings between a Central PCA system and a
Point-of-Use (POU) system under the LEED V4, Energy and Atmosphere or Innovation credits.
This should be explored because the PCA will be coupled with the CEP, and if it is not pursued
as an Energy Conservation Measure (ECMEnergy conservation measures are installations or modifications of equipment or systems intended to reduce energy use and costs.), it would otherwise dilute the total building energy
savings. The expected energy use is half of the POU annually, which will comprise a healthy
portion of the total building energy consumption.
This system arrangement has (2) key ECM’s;
1. Using 42⁰F CHWS for 1st stage of cooling. This lowers the EWT into the PCA chillers
from 60⁰F to 44⁰F.
2. Using 56⁰F CWR for the PCA Chiller Condenser Water Source.
System Descriptions for Exceptional Calculations;
1.4.2 - ASHRAE 90.1 Section 6: HVAC (Air-Side)
Include units for all relevant inputs
Model Input Parameter / Energy Efficiency Measure Baseline Case Proposed Case
Primary HVAC Type1 PC Air Unit PC Air Unit
Unitary Cooling Capacity Ranges3 25-90 Tons 25-90 Tons
Unitary Cooling Efficiency4 2.5 KW/Ton 0.75 KW/Ton
Unitary Heating Capacity Ranges5 same as proposed TBD
Fan System Operation VFDA variable frequency drive (VFD) is a device for for controlling the speed of a motor by controlling the frequency of the electrical power supplied to it. VFDs may be used to improve the efficiency of mechanical systems as well as comfort, because they use only as much power as needed, and can be adjusted continuously. VFD
Outdoor Air Design Min Ventilation7 100% OA 100% OA
HVAC Air-side Economizer CycleA heating, ventilation, and air-conditioning (HVAC) conservation feature consisting of indoor and outdoor temperature and humidity sensors, dampers, motors, and motor controls for the ventilation system to reduce the air-conditioning load. Wherever the temperature and humidity of the outdoor air are more favorable (lower heat content) than the temperature and humidity of the return air, more outdoor air is brought into the building. Y Y
EconomizerAn economizer is a device used to make building systems more energy efficient. Examples include HVAC enthalpy controls, which are based on humidity and temperature. High-Limit Shutoff 40 DEG F 40 DEG F
3 | P a g e
1.4.3 - ASHRAE 90.1 Appendix G: HVAC (Water-side)
Include units for all relevant inputs
Model Input Parameter / Energy Efficiency Measure Baseline Case Proposed Case
The Project Has District Heating (Y/N) N N
The Project Has District Cooling (Y/N) N Y
District Cooling Plant Efficiency
-
CHILLER KW/TON +
PUMPS KW/TON +
COOLING TOWER
KW/TON
ESTIMATED = 0.9
KW/TON
District Cooling Plant PCA Capacity - 600 TONS
PCA Plant - Number of Chillers - 3
PCA Chiller Part-Load Controls1 - VFD
PCA Chiller Capacity (Per Chiller) - 300 TONS
PCA Chiller Efficiency2 - 0.58 KW/TON
PCA Glycol Water Loop Supply Temperature - 20 DEG F
PCA Glycol Water (CHW) Loop Delta-T - 40 DEG F
PCA GS Loop Temp Reset Parameters
TBD. EXAMPLE:
OAT<40 DEG F, GST
= 28 DEG F.
PCA Glycol Loop Configuration3
VARIABLE PRIMARY
Number of Primary CHW Pumps 3
Primary CHW Pump Power 75 HP
Primary CHW Pump Flow 324 GPM
Primary CHW Pump Speed Control VFD
Condenser Water Leaving Temperature 66 DEG F
Condenser Water (CW) Loop Delta-T 10
CW Loop Temp Reset Parameters -
Number of CW Pumps 3
CW Pump Power 25 HP
CW Pump Flow 922
CW Pump Speed Control CV
PEAK DESIGN DAY LOAD PROFILE

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Marcus Sheffer LEED Fellow, 7group Nov 29 2016 LEEDuser Expert 69162 Thumbs Up

So your project is an airport terminal and you are seeking to show process load savings? Assuming so it would not be eligible for an innovation credit since energy savings are already addressed by an existing LEED credit. It may be eligible for an exceptional calculation. The key to a successful exceptional calculation is built on the justification used for establishing the base case. The base case should be based on standard practice in the industry in that location. You will need to provide justification that the base case you select is standard practice. This can come from a variety of sources like previous projects in the area, utility rebate programs, studies, trade group letters, exceeding minimum code requirements, etc. The more you can find to justify the base case the better off you will be.

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Jennifer Holmes Chief Mechanical Engineer Design Alaska
Nov 22 2016
LEEDuser Member
2 Thumbs Up

V4 District Thermal Energy

What guidelines should be used for district thermal energy systems in v4 when using option 1, specifically combined heat and power systems? The credit language does not clarify how it should be modeled and I could not find any guidance documents on USGBC's website. ASHRAE 90.1-2010 has a section on purchased heat but this section was excluded in v2009.

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Marcus Sheffer LEED Fellow, 7group Nov 23 2016 LEEDuser Expert 69162 Thumbs Up

The DESDistrict energy system: a central energy conversion plant and transmission and distribution system that provides thermal energy to a group of buildings (e.g., a central cooling plant on a university campus). It does not include central energy systems that provide only electricity. modeling methodology has been incorporated into the Reference Guide for v4 and is now mandatory. It is under Further Explanation - Project Type Variations.

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Charalampos Giannikopoulos Senior Sustainability Consultant DCarbon
Nov 16 2016
LEEDuser Member
1836 Thumbs Up

Industrial or non-regular process load

For a facilities with increased process load (more than 60%), other than data centers, including but not limited to industrial facilities, is there a particular guidance in establishing a baseline case different from the design one similar to the approach used for data centers with the corresponding energy performance calculator? Unless an exceptional calculation method is used it seems that for such facilities the energy prerequisite might be unattainable. Finally, would Interpretation 10291 for high unregulated process loads applicable to v4? Thank you in advance.

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Marcus Sheffer LEED Fellow, 7group Nov 16 2016 LEEDuser Expert 69162 Thumbs Up

Some of the guidance is concrete and some not so much. If you can point to some sort of standard it is clear - say boiler efficiency for a process boiler you can point to 90.1. This could apply to motors, chillers, etc.

For specialty equipment the baseline is standard industry practice in that area. This gets harder to define. So you have to do the research to justify the baseline. There is just so many different specialize process equipment that it would be extremely difficult to create a baseline for each.These types of facilities need to do an exceptional calculation to show enough savings.

I think that the documentation methods in that interpretation would still apply to v4.

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Charalampos Giannikopoulos Senior Sustainability Consultant, DCarbon Nov 20 2016 LEEDuser Member 1836 Thumbs Up

Thanks Marcus. That said I guess that Interpretation 10291 still applies to v4.

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Victoria Watson
Sep 28 2016
LEEDuser Member
249 Thumbs Up

Tri-gen

Project Location: United States

Hi, I am QA'ing a model for a building that will be fed via a cogenerationThe simultaneous production of electric and thermal energy in on-site, distributed energy systems; typically, waste heat from the electricity generation process is recovered and used to heat, cool, or dehumidify building space. Neither generation of electricity without use of the byproduct heat, nor waste-heat recovery from processes other than electricity generation is included in the definition of cogeneration. plant (with absorption chillers) and therefore is a little complicated. The cogen plant is owned by the utility (which is technically owned by the municipality which owns the building being built). The building will purchase the electricity from the utility at a reduced rate and get the waste heat for free.

It has been modeled as:
- The proposed purchases the electricity generated by cogen at the reduced rate with the remainder being purchased at standard rate (15% more)
- The baseline is modeled with standard systems and uses the grid supplied gas rate and standard rate for all electricity
- The proposed pays for gas at the grid supplied rate for the purpose of the model

Does this approach sound valid?

Key Q's I think are:
1) is it ok to use different fuel costs for the electricity generated vs. consumed (and therefore proposed and baseline blended rates will be different) if this is as per the contract

2) Should the proposed pay for gas (even if free in reality) and if so should it be a direct purchase amount for the load or should it take account of the CHPCombined heat and power (CHP), or cogeneration, generates both electrical power and thermal energy from a single fuel source. efficiency (E.g. 40% thermal)

Thanks

Victoria

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Marcus Sheffer LEED Fellow, 7group Oct 31 2016 LEEDuser Expert 69162 Thumbs Up

1. You will need to follow one of the paths in Appendix D of the DESv2. Then follow the rate guidance in section 2.4.2.2.

2. Yes you pay for the gas accounting for the CHPCombined heat and power (CHP), or cogeneration, generates both electrical power and thermal energy from a single fuel source. efficiency.

You will use the same rates for both models but the difference plays out in the allocation of energy use associated with the central plant. In particular the proportional CHP production of electricity gets entered in the form as a negative value.

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Charles Daze Project Engineer Burns & McDonnell
Sep 26 2016
LEEDuser Member
57 Thumbs Up

100% OA Laboratory System

Project Location: United States

I have a HVAC system with labs on it requiring 100% outside air systems. Following all the guidance in 90.1 these spaces require a dedicated Sys 5/7 because they are over 5,000 cfm. Also my proposed design varies lower than 50% during unoccupied times with air quality sensing.

It is my understanding that the baseline should not vary less than 50% and I can show savings for that difference.

I have seen other comments on the internets about that difference in airflow not being allowed to be OA. Is this accurate? This seems illogical to me on a 100% lab system. Why would be baseline get savings potential of being able to return lab air?

Anyone have any insight on modeling Lab systems for LEED.

-Thanks

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Marcus Sheffer LEED Fellow, 7group Oct 06 2016 LEEDuser Expert 69162 Thumbs Up

Sounds like you are citing the exception to G3.1.3.13. There is more to this than the 50% limit, so make sure the Baseline is modeled accordingly.

Under 90.1-2007 the OA must be identical. In 90.1-2010 the OA will vary (Baseline is minimum 62.1-2010 calculated and Proposed is as designed).

I would think that this is an area where you could demonstrate savings through an exceptional calculation.

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Victoria Watson
Sep 21 2016
LEEDuser Member
249 Thumbs Up

Demand Control Ventilation

Can you take credit for occupancy sensors that control HVAC systems? I am thinking probably not for system operation E.g setbacks, agree? But I am unsure for the ventilation. It seems a bit waffly trying to determine when the spaces are "occupied" as technically they are 24/7 but occupant will come and go during that time. Should the baseline be 24/7 for ventilation and the proposed as per expected design for ventilation taking account occupancy sensors...? Thanks

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Marcus Sheffer LEED Fellow, 7group Sep 23 2016 LEEDuser Expert 69162 Thumbs Up

You can do so as an exceptional calculation. See the Appendicies of the Advanced Energy Modeling Guide for LEED for an example. Make sure you can defend the schedule adjustment associated with the occupancy patterns..

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Julien Richard Artelia
Sep 08 2016
Guest
119 Thumbs Up

Exterior lighting power

Project Location: France

Hello,

We have a project where some luminaires have more power than what it is required by the mandatory provisions of exterior lighting power.
However the actual power necessary to obtain the lumens needed for the project is below the power requirement. So we plan to lock the power of the luminaire during its installation so it will never exceed the mandatory requirement. We think of this approach because the exterior lighting designer cannot find a luminaire with the exact wattage needed.

1) Do you think this approach is acceptable?
2) How to show compliance during the design review as the technical documentation of the luminaires will show a non-compliant wattage? Does it seems acceptable if we include the requirements of blocking the power in the construction documents?

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Marcus Sheffer LEED Fellow, 7group Sep 08 2016 LEEDuser Expert 69162 Thumbs Up

I am a bit confused by the question since compliance is determined based on the watts/area or linear feet and not by the individual fixture. So individual luminaires can't have more power than required.

1. Maybe. See the exception to 9.1.4.
2. Demonstrate compliance with the exception to 9.1.4.

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Julien Richard Artelia Sep 13 2016 Guest 119 Thumbs Up

Thanks Marcus! The exception seems to apply.

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Marcus Sheffer LEED Fellow 7group
Aug 22 2016
LEEDuser Expert
69162 Thumbs Up

Excellent Modeling Guide

In case you have not seen this relatively new guide I would highly recommend it to help with your modeling issues.

ANSI/ASHRAE/IES Standard 90.1-2010 Performance Rating Method Reference Manual

http://www.pnnl.gov/main/publications/external/technical_reports/PNNL-25...

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Ignacio Furniés LEED BD+C Energy modeling / sustainability consulting Revitaliza Consultores
Aug 05 2016
Guest
6 Thumbs Up

Manufacturing process

Project Location: Mexico

My question is regarding the EAp2 and EAc3, our project consists of a palm oil manufacturing facility. The energy intensive manufacturing process exceeds an estimated 90% of the facility's total energy load. So, according to LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. #10159 we need energy consumption from at least 3 other facilities in order to document/compare our energy efficiency. We have tried by every means contacting other manufacturing facilities and the equipment manufacturer but we haven't succeeded. What advise could you give us on this? Is there any other way we can document the compliance for the prerequisite and credit?

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Marcus Sheffer LEED Fellow, 7group Aug 09 2016 LEEDuser Expert 69162 Thumbs Up

The comparison to other facilities is just one acceptable method. The overall issue is that you need to establish the baseline for comparison relative to any energy savings claimed for the process loads. This can be accomplished several ways. Cite a standard, or utility program, or studies, or any means that you can figure out to justify the baseline. Additionally, it is often helpful to demonstrate that the strategy you are installing to save energy is not standard practice in that particular industry in that location.

That said I hope you realize the potential irony of claiming a green building certification for a palm oil factory given the devastating environmental effects of growing and producing it. Perhaps they are using some new sustainable way to grow and make it and I don't know the particulars of this situation so I am just responding in generalities.

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Adrien Dumolard HVAC Engineer Artelia
Aug 03 2016
Guest
3 Thumbs Up

90.1 2010: V4: Baseline Lighting Control

Project Location: France

Hello,
I work on my first PRM.
In the 9.4.1.2 mandatory provisions, the standart say:
"The controlled lighting shall have at least one control step between 30% and 70% (inclusive) of full lighting power in addition to all off." but we talk about manual control.
I don't understand if the baseline shall or not have automatic control.
Thanks for your help.

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Marcus Sheffer LEED Fellow, 7group Aug 04 2016 LEEDuser Expert 69162 Thumbs Up

See Table G3.1-6 Baseline. The Baseline shall have manual and automatic controls as indicated in Section 9.4. The specific item you mention can be accomplished with manual or automatic controls.

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Muzamil Rafique
Jun 28 2016
Guest
175 Thumbs Up

Energy Simulation

Project Location: Pakistan

Hello Marcus,

i want some clarification regarding HVAC Baseline and Proposed model. According to Table G3.1.1A and Table G3.1.1B and as per proposed building type and heating fuel the HVAC baseline in our case is System 6(Packaged VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. with PFP Boxes) . My proposed design HVAC system Chiller based.
Now i am going to simulate these systems on software.

1 In simulation software i select for proposed case chiller (plant) but in baseline i select the packaged rooftop system. Is it correct or not or select the same system for both model?
2 Select same system (Packaged rooftop )in both model but use different specification i.e(Fan power, cooling,heating capacities) is it okay or not?

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Marcus Sheffer LEED Fellow, 7group Jun 28 2016 LEEDuser Expert 69162 Thumbs Up

1. Correct. The systems should be different.
2. No. I am guessing that your proposed system would have air handlers not packaged systems.

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Muzamil Rafique Jun 28 2016 Guest 175 Thumbs Up

1.Yes Proposed system have air handler and baseline have package rooftop.i selected these both systems but end saving going to negative.

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Muzamil Rafique Jun 28 2016 Guest 175 Thumbs Up

Is it possible i simulate the both model identically without heating coil due to software limitation.

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Marcus Sheffer LEED Fellow, 7group Jun 28 2016 LEEDuser Expert 69162 Thumbs Up

No you must model the proposed as designed and the baseline according to Appendix G.

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Muzamil Rafique Jun 28 2016 Guest 175 Thumbs Up

Thank you Marcus

1.When i select HVAC baseline System 6 "Packaged rooftop VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. with reheat" heating is not show in end report. when i include the preheat coil in baseline system the heating is show in end report. Is it acceptable or not.

2.what about the ventilation sizing method. It is identically or different in both model i.e proposed model ventilation sizing method is "SUM OF SPACE OA AIR FLOW". and in baseline model as per "ASHARE std 62.1".

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Marcus Sheffer LEED Fellow, 7group Jun 29 2016 LEEDuser Expert 69162 Thumbs Up

1. Not enough information to say. If there is heating energy use in the baseline and no heating energy use in the proposed it will likely not be acceptable without a thorough explanation.
2. That sounds like the correct methods. Make sure the quantity of OA is identical unless you have demand controlled ventilation in the proposed.

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Muzamil Rafique Jun 29 2016 Guest 175 Thumbs Up

Thank you Marcus,
Yes heating energy used in both models. The problems becomes only in Baseline Model. The software has no provision heating in VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. system. if i select the Preheat coil, the heating is showen in output summary. Now the question is that Can i use the "Preheat coil" only in Baseline model for heating.

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Marcus Sheffer LEED Fellow, 7group Jun 29 2016 LEEDuser Expert 69162 Thumbs Up

Sorry i was confused on your previous post. You should be able to model electric reheat coils in the baseline system in HAP. The heating in the baseline must be reheat coils, it can't be only in the preheat coil. You can only model a preheat coil in the baseline if G3.1.2.3 applies to your situation.

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Jennifer Webb CEO JWAC
Jun 27 2016
LEEDuser Member
13 Thumbs Up

insulation thickness versus energy modeling

Project Location: United States

We are running into a situation where the insulation is slightly under the R38 (R34.8) that is required per ASHRAE 90.1 yet the energy model shows we are over 10% energy efficient. Will this still meet the LEED v4 requirement?

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Marcus Sheffer LEED Fellow, 7group Jun 27 2016 LEEDuser Expert 69162 Thumbs Up

Yes. The insulation value is a prescriptive measure so it is available for trade off.

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Isabel Santos ECOCHOICE SA
Jun 23 2016
Guest
108 Thumbs Up

USGBC-approved equivalent standard for projects outside the U.S.

Project Location: Portugal

Dear all,

We are a consultant company beginning the application for LEED v4 certification of a major renovation project.
We would like to know if we could assess the Minimum Energy Performance prerequisite and Optimize Energy Performance credit according to the Portuguese Energy Certification System (“Sistema Certificação Energética dos Edifícios (SCE)”). This is the only energy certification system used in Portugal and is mandatory for new buildings and major renovations.

Thank you in advance!

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Marcus Sheffer LEED Fellow, 7group Jun 24 2016 LEEDuser Expert 69162 Thumbs Up

I am not aware that any of the European standards have demonstrated equivalence to 90.1. This is a pretty involved process and would usually be undertaken by a a governmental agency or perhaps a nonprofit with funding to do so.

The issue in LEED is that equivalency needs to be demonstrated to ensure that the percent savings and the point scale is associated with a baseline that would produce similar or conservative results.

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Fleur Baguley Carbon Consult Limited
Jun 23 2016
Guest
3 Thumbs Up

Energy Modelling - United Kingdom

Project Location: United Kingdom

Hi, I have a project in the UK. For schemes such as BREEAMBuilding Research Establishment Environmental Assessment Method, the first widely used green building rating system, developed in the U.K. in the early 1990s, currently used primarily in the U.K. and in Hong Kong. we use a SBEM - BRUKL output for the energy credits. Does anyone know if this is compliant to use for LEED as well? Or is an ASHRAE model still required? Thanks

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Marcus Sheffer LEED Fellow, 7group Jun 24 2016 LEEDuser Expert 69162 Thumbs Up

I am not aware that any of the European standards have demonstrated equivalence to 90.1. This is a pretty involved process and would usually be undertaken by a a governmental agency or perhaps a nonprofit with funding to do so.

The issue in LEED is that equivalency needs to be demonstrated to ensure that the percent savings and the point scale is associated with a baseline that would produce similar or conservative results.

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Shaun Wang Dr. Oct 06 2016 Guest 13 Thumbs Up

Don't think SBEM meets the minimum requirement of ASHRAE 90.1 Appendix G for modeling software (G2.2), such as 8760 hours per year, thermal mass effects, precisely defined and manipulated HVAC systems etc.

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Muzamil Rafique
Jun 23 2016
Guest
175 Thumbs Up

Building Orientation

Project Location: Pakistan

Hello Marcus,

1.My project orientation on NW,NE,SW and SE. But V4_Minimum energy performance calculator_spreadsheet have only North,East,West and South options, and spreadsheet not allow to change this option. Can i fill these cells as per spreadsheet and write a Narrative about orientation for reviewer.
2.Heating is required in Pakistan only in four months.I set my heating schedule for four month(Jan,Feb,Nov,Dec) and identically in Base and Proposed models. Is it acceptable or not ?
3.Cooling and Heating capacities model as per design in proposed case. but unfortunately my software have no option of auto-sized with 15% for cooling and 25 % for heating. How manipulate this problem?If i put manually these values with increased 15% and 25% form design,Is it acceptable for reviewer and write a narrative for reviewer and tell him about my calculation.

Thank you in Advance

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Marcus Sheffer LEED Fellow, 7group Jun 23 2016 LEEDuser Expert 69162 Thumbs Up

1. Pick the closest orientation for each label. The specific direction does not matter.
2. Yes
3. HAP does have this option when auto-sizing the system. The best way to do this is as an over-sizing factor. I have also seen it applied as a saftey factor but this is not the preferred method.

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Muzamil Rafique
Jun 22 2016
Guest
175 Thumbs Up

Energy Modeling

Project Location: Pakistan

Dear All,
i am doing a energy simulation for bank building. software have no option LEED Rating V4. It have only LEED 2009 rating system. Can i use this rating system for V4 only in software for energy simulation.

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Marcus Sheffer LEED Fellow, 7group Jun 22 2016 LEEDuser Expert 69162 Thumbs Up

What software are you using?

You can probably use it for v4 but you may need to create the baseline yourself. I am guessing that the option you refer to is used to help create the baseline model.

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Muzamil Rafique Jun 23 2016 Guest 175 Thumbs Up

I am using Hourly Analysis Program.

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Marcus Sheffer LEED Fellow, 7group Jun 23 2016 LEEDuser Expert 69162 Thumbs Up

HAPv4.91 appears to have added the ASHRAE 90.1-2010 baseline options.

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Muzamil Rafique Jun 23 2016 Guest 175 Thumbs Up

Which software is best option for Energy simulation.

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Marcus Sheffer LEED Fellow, 7group Jun 23 2016 LEEDuser Expert 69162 Thumbs Up

They all have their strengths and weaknesses. Here is a comprehensive list of the available tools - http://www.buildingenergysoftwaretools.com/

We mostly use eQUEST. It is free but has no real customer service. It can't model certain strategies so we use EnergyPlus (DesignBuilder) sometimes. We have trained in IES VE but have not used it on a project yet. The best software is the one you know best and the one that can model accurately what you want to model.

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Muzamil Rafique Jun 23 2016 Guest 175 Thumbs Up

I best know the HAP software.
HAP create problem in HVAC system Baseline Case. This is not acceptable for reviewers, and i have done my maximum effort on HAP software.

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Marcus Sheffer LEED Fellow, 7group Jun 23 2016 LEEDuser Expert 69162 Thumbs Up

HAP can work for the reviewers. Sounds like maybe you just need the latest version.

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Muzamil Rafique Jun 23 2016 Guest 175 Thumbs Up

Thank you

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