-
Beyond code compliance, but doable
This prerequisite is a big one, not only because it’s required for all projects, but also because it feeds directly into EAc1: Optimize Energy Performance, where about a fifth of the total available points in LEED are at stake. Master these minimum requirements, and you can use the same compliance path as in EAp2 to earning points.
You won’t earn the prerequisite by accident, though. Although “energy efficiency” is on everyone’s lips, the mandatory and performance-based requirements for EAp2 go beyond code compliance in most places. That said, there is nothing to stop you from meeting the requirements with a reasonable amount of effort, and the environmental benefits as well as the operational cost savings are significant.
Most projects start by...
Step-by-step credit help
Got the gist of the LEED credit but not sure how to actually achieve it? LEEDuser gives step-by-step help. Members get:
- Checklists covering all the key action steps you'll need to earn the credit.
- Hot tips to give you shortcuts and avoid pitfalls.
- Cost tips to assess what a credit will actually cost, and how to make it affordable.
- Ideas for going beyond LEED with best practices.
- All checklists organized by project phase.
- On-the-fly suggestions on useful items from the Documentation Toolkit, Resources, and Credit Language.
-
Credit language straight from USGBC
Need to check up on the exact LEED credit language from the LEED Rating System on the fly? LEEDuser includes the verbatim language. Members get:
- Easy access to the official LEED credit language with just a couple of clicks.
- On the jobsite without your bulky LEED Reference Guide? Check up on the credit language details here.
- Credit language content is used by permission of the U.S. Green Building Council.
Your credit-by-credit reference library
Why waste time chasing down referenced standards and supporting resources when LEEDuser links you directly to the ones you need? LEEDuser has gathered all the best tools out there and organized them by credit for easy reference. Members get links to:
- Organizations that can give information or help on a credit.
- Standards or studies that are key reference points for credits and prerequisites.
- Articles that help explain important topics.
- Key documents or references for credit inputs.
- Software tools you can use to run calculations or simulations.
Documentation Toolkit
In the end, LEED is all about documentation. LEEDuser’s Documentation Toolkit saves you time and helps you avoid mistakes with:
- Calculators to help assess credit compliance.
- Tracking spreadsheets for materials purchases.
- Spreadsheets and forms to give to subs and other team members.
- Guidance documents on arcane LEED issues.
- Sample templates to help guide your narratives and LEED Online submissions.
- Examples of actual submissions from certified LEED projects.
432 Comments
Using campus utilities
My new building design utilizes steam and domestic hot water generated from a central utility plant on campus. How do I handle this in my energy model? Thanks.
Motor Efficiencies for projects outside the US
I was wondering whether anyone has come across the motor efficiency issue for projects outside the US. We have a project in EU and the motor efficiencies are different to the ones shown on 90.1 mandatory provisions on 10.4 (Table 10.8) because of the difference of the frequencies; 50Hz in EU versus 60 Hz in US.
There is this article (http://www.reliableplant.com/Read/19531/harmonizing-international-motor-...) that compares the European Standard with the US EPAct ‘92 and says that the IE2 (International Efficiency 2) is equivalent to U.S. EPAct for 60 Hz. The design team has specified motors with IE2. Would the project meet the mandatory provisions on 10.4 if these motors are installed?
Many thanks for any help provided.
Using a newer version of 90.1 than what LEED specifies
I am working on a project that was registered under LEED NC 2.2. Will the USGBC allow us to apply requirements from 90.1 - 2010 to the project instead of 90.1 - 2004? Specifically what I am interested in is the performance requirements for closed circuit cooling towers. In 90.1 - 2004 the performance requirements for a centrifugal fan cooling tower (which is what we have) is listed at >= 20 gpm/hp. While in 90.1 - 2010 the performance requirements for a Centrifugal open-circuit cooling tower is also >= 20 gpm/hp but the requirements for a centrifugal closed-circuit cooling tower is >= 7 gpm/hp. As I stated before we have a centrifugal fan closed-circuit cooling tower, so what I would like to do is apply the requirements from 90.1 - 2010 instead of 90.1 - 2004. It looks like the new requirements are more accurate than what the old requirements are due to the splitting of the requirement into closed and open circuits.
Thanks again!
You will need to follow the 2004 baseline requirements. You can use any addenda to 2004. The changes in 2010 were either new items or addenda to 2007 and can't be used on 2004 projects.
Marcus,
Does it make a difference that this efficiency figure does not affect the model at all? My original question was not in reference to the baseline model, it was in reference to the proposed design meeting the mandatory requirements of 90.1. I understand that LEED NC 2.2 references 90.1 - 2004 but it seems funny that the USGBC would have an issue with a product that meets the 90.1 - 2010 requirements. The project was also designed in 2010.
In your opinion, what would happen if I included a copy of the table from 90.1 - 2010 in my LEED submittal showing the new requirements and a written narrative describing that the proposed product meets the intent of 90.1 - 2004 because of the clarification that came in 2010?
Thanks again for all of your expertise and help!
You almost always model the Proposed as designed. You should be fine using the clarification from 2010 to meet the mandatory provision. See 90.1-2004 Section 6.4.1.3 which indicates that equipment not listed can be used. I would simply provide the narrative you suggest explaining that the equipment you are using is not covered but instead of citing 2010 I would supply product information on the tower you are using.
Awesome. Thanks again for your expertise and help Marcus!
90.1-2007 Table G3.1.1A for Additions and Alterations
Do the requirements of Table G3.1.1A Baseline HVAC System Types apply to the whole building or just to the project area for additions and alterations? I am working on a project renovating a large existing sports complex. The existing building area is over 150,000 square feet, but the renovation project area is about 17,000 square feet. Would this fall under System 7/8 or System 3/4?
This question is also applied to the heating source. If the existing building uses fossil fuel, but the project area uses 100% electric, would my baseline system fall under the fossil fuel column or electric?
If the project is an addition and renovation and the rest of the building is not part of the scope of work for LEED then just count the project area and the systems it contains.
Modeling Narrative Upload?
I am documenting an energy model for LEED 2009 EAp2/EAc1 and I would like to include a document that describes the modeling techniques used for each modeled system. The reason that we would like to include this document is that the software that we used (HAP) was unable to directly model one of our systems (rooftop WLHP tied to 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. boxes) so we had to use a work-around to accurately model the system inside of the software. Because of how we chose to model this system, we were able to get accurate final results out of the the software without doing any exceptional calculations outside of the software.
Should this write-up be uploaded as an exceptional calculation with zeros entered in to the form for the exceptional calculation energy savings? Or is there another way to bring this document to the reviewer's attention?
Thanks!
If you used a work-around no need to submit an exceptional calculation. Simply upload a narrative explaining the work-around.
Having Trouble Getting Compliance for EAp2
I am working on a LEED project and we hired an engineer to run an energy model on EQuest. He then submitted all the required forms and entered all of the information onto the associated form, however we can't simply get this credit resolved. Are there any other credits that need to be completed first - a prerequisite to a prerequisite if you will? As an example, does EAp1 or EAc1 need to be completed before getting the points with EAp2? Any help would be appreciated,
EAp2 is the prerequisite and there are no points associated with it. However, this prerequisite (EAp2) must be resolved before any points can be awarded for EAc1 if it has been denied after two reviews (preliminary and final) and there were no partial points determined by the reviewer.
If you are at that point then you need to demonstrate that the reviewer is wrong or appeal EAp2. If you appeal EAp2, EAc1 is automatically included and you do not need to appeal it separately.
Utility Service Changed During Construction
Hello -
My project submitted, and received approval, of our energy model based on natural gas DHWDomestic hot water (DHW) is water used for food preparation, cleaning and sanitation and personal hygiene, but not heating. heating and everything else electric. I recently discovered that they installed all electric in the building due to issues with the local utility provider. (This is a light commercial project for a large franchise). We are also pursuing M&V. I now have conflicting information between my design and construction submissions. It seems there are three options: 1) modify design credits to installed - expensive!, 2) submit construction credit with installed condition and add a note of explanation - risk being rejected, or 3) base the construction credit on the designed system - reduces the value of the credit to the project. How do I proceed?
When doing a split submission you are required to state that nothing changed during construction to affect previously approved credits when you submit your construction credits. You are technically required to update the energy model to reflect what was built. This is why we always defer the energy model until the construction submission.
When it comes to M&V the whole idea is to verify predicted savings. So if you already know your prediction is flawed, the correct action is pretty obvious( #1).
If you do #2 it would automatically open your previously approved energy model to further review. If you do #3 you will knowingly be submitting inaccurate information.
Great, thank you so much. I thought that was the answer, but needed to verify it for my project team. Very helpful and I appreciate the quick response!
Energy Savings via DHW Savings?
Does LEED NC v2009 allow us to model and receive credit for energy savings resulting from DHWDomestic hot water (DHW) is water used for food preparation, cleaning and sanitation and personal hygiene, but not heating. conservation due to the installation of low-flow fixtures inside of apartments in a multifamily building?
Thanks.
Yes. Make sure the savings are related to the calculations for WEc3 and that you explain how you calculated the savings.
Pool Cover and Air souce heat pump
Can the mandatory requirement of swimming pool cover be exempted if an air-souce heat pumpA type of heating and/or cooling equipment that draws heat into a building from outside and, during the cooling season, ejects heat from the building to the outside. Heat pumps are vapor-compression refrigeration systems whose indoor/outdoor coils are used reversibly as condensers or evaporators, depending on the need for heating or cooling. In the 2003 CBECS, specific information was collected on whether the heat pump system was a packaged unit, residential-type split system, or individual room heat pump, and whether the heat pump was air source, ground source, or water source. is used for pool heating?
The pool is heated to 30 ºC, is the pool cover mandatory in this case.?
The exception under 7.4.5.2 can apply to many heat pumpA type of heating and/or cooling equipment that draws heat into a building from outside and, during the cooling season, ejects heat from the building to the outside. Heat pumps are vapor-compression refrigeration systems whose indoor/outdoor coils are used reversibly as condensers or evaporators, depending on the need for heating or cooling. In the 2003 CBECS, specific information was collected on whether the heat pump system was a packaged unit, residential-type split system, or individual room heat pump, and whether the heat pump was air source, ground source, or water source. based systems.
LEED boundary and Major Additions
A new project, under LEED-NC, is a major addition to an existing building, in this case a manufacturing facility which will result in basically three sections New Office, Existing Office, and Existing Manufacturing Area. Can the LEED boundary and energy credit only include the addition(office) and existing building(office) if both the new addition (office), existing building(office), and existing building (manufacturing plant) all share a common central plant? The energy from the plant will be apportioned appropriately to 2 of the 3 building sections. Seem reasonable? Thanks.
I understand why you might want to exclude the manufacturing area but technically the whole project should be included in the LEED submission.
MPR #2 indicates that the entire project should be included.
Standard baseline for each piece of medical equipment
I am building a model for healthcare project and trying to save energy use as much as possible, but the energy use of medical equipment is huge. There are some comments about finding the standard baseline for each piece of medical equipment and use it as the baseline energy. Finally I found the energy use of three different brands of medical equipment, but I have no idea how to use it. Could I use the average as the baseline energy? Will it be accepted? Does anyone have the experience of finding the standard baseline for each piece of medical equipment?
Thank you.
See the medical equipment pilot credit.
http://www.leeduser.com/credit/Pilot-Credits/PC3
How do you define "baseline" or "industry average"? Is a baseline of a piece equipment such as an average power consumption of three products of other makes sufficient? Is there a minimum number of other makes that you have to find?
Because what we are trying to find is the baseline of proton therapy machine, and there are not that many companies manufacture it (only 3 or 4).
The common phrase used is "standard industry practice". So if you are looking at a particular piece of equipment I would not take the average of what is on the market. I would tend to look at it like Energy Star, the top 20% or so of the market qualifies. So document each and show that you bought the one that is most efficient. Then claim the energy savings through the exceptional calculation method.
DES Baseline
For HVAC System, Our project team will apply to 2 absorption chillers and geo-exchange heat pumpA type of heating and/or cooling equipment that draws heat into a building from outside and, during the cooling season, ejects heat from the building to the outside. Heat pumps are vapor-compression refrigeration systems whose indoor/outdoor coils are used reversibly as condensers or evaporators, depending on the need for heating or cooling. In the 2003 CBECS, specific information was collected on whether the heat pump system was a packaged unit, residential-type split system, or individual room heat pump, and whether the heat pump was air source, ground source, or water source..(project site is located in DES)
In this case, we know that the baseline system of HVAC is absorption chiller(applied DES guideline/ Baseline system type is 7).
But, I don't know what is the baseline system for geo-exchange system(It is not renewable energy)
Thank you for your help.
Typically there is one baseline system unless one of the exceptions in G3.1.1 applies. The baseline system is usually based on the size and heating fuel type.
Building Simulation for a non AC Facility
We are working in a Garment Factory project in SriThe solar reflectance index (SRI) is a measure of a material's ability to reject solar heat, as shown by a small temperature rise. Standard black (reflectance 0.05, emittance 0.90) is 0 and standard white (reflectance 0.80, emittance 0.90) is 100. For example, a standard black surface has a temperature rise of 90_F (50_C) in full sun, and a standard white surface has a temperature rise of 14.6_F (8.1_C). Once the maximum temperature rise of a given material has been computed, the SRI can be calculated by interpolating between the values for white and black. Materials with the highest SRI values are the coolest choices for paving. Because of the way SRI is defined, particularly hot materials can even take slightly negative values, and particularly cool materials can even exceed 100. Lanka where the facility is to be LEED certified. Whole building will be put up as a non air conditioned facility. mechanical ventilation systems would be installed to provide fresh air to the building. since the facility is located in an area with a tropical climate occupants are assured to have required thermal comfort.
But the problem we are having is since ASHRAE 90.1 is developed for Air conditioned facilities is it possible for us to claim energy savings for this particula facility through an energy simulation based on ASHRAE 90.1 standards. We will not claim any credits for air conditioning and only hope to claim credits for savings on artificial lighting. will this procedure be accepted?
if the above is not possible should we go for a manual calculation to prove energy savings? but the LEED guideline says manual calculations are accepted only when the simulation can not be used to reflect the actual scenario. how would this clause affect here? please advice on the best way forward. thanks in advance.
You are required to include air conditioning in both models by 90.1. Simply model the air conditioning but set the temperatures the same and high enough so that it does not come on.
Thanks Marcus. so does that mean even we don't have air conditioning installed for real in our project it is possible to simulate the building as per ASHRAE 90.1?
Yes it is possible for LEED.
Modeling Multiple Buildings
I am working on a new project which consists in 5 buildings, all have its own HVAC system designed, 3 of them have a complete HVAC, and the other 2 will only have Mechanical Ventilation to cool the building (project in central Mexico no heating needed). My approach is to model each building independently and then add up the results. My question is if for the 2 buildings that only have Mechanical Ventilation I should also include cooling and heating, according to appendix G I should if they were individual buildings. Any advice would be grateful.
Technically you should but you can set the temperatures consistently in both so that neither system comes on.
Make sure you look at the MPRs regarding multiple building project under LEED 2009.
Existing Building undergoing major renovation
ASHRAE 90.1 states that existing buildings shall be modeled as is before renovations. Currently the building has all of the window openings boarded up. I'm thinking that the best scenario would be to model the area of the window openings to be consistent and assign a u-value associated with plywood to the "window" and a SHGCSolar heat gain coefficient (SHGC): The fraction of solar gain admitted through a window, expressed as a number between 0 and 1. of 0. Has anyone encountered this situation before, if so is this logic correct? Thanks.
I think you need to apply some sense of logic to these situations. As an example, would it be appropriate to model an existing condition as an open hole in the wall even if that was the case?
Assuming that the current opening will be filled with windows I would model windows in the baseline. If this is an old building that had windows, I would likely model single pane windows in the baseline, not plywood. If this was a newer building, say built since the common use of double pane glass, I would use a double pane window. If the building had metal frames, I would use that in the baseline. If wood frames, I would use that.
There are values in Table A8.2 for unlabeled vertical fenestration you could use as a default.
Based on ASHRAE fundamentals, the u-values are almost identical for 5/8 inch plwood and single pane windows from Table A8.2.
Sounds right and with a SHGCSolar heat gain coefficient (SHGC): The fraction of solar gain admitted through a window, expressed as a number between 0 and 1. entered for the windows your baseline will be a more thermodynamically comparable model to the Proposed.
Baseline HVAC system and envelope for hospital patient rooms
I'm not sure of the Baseline envelope and HVAC system to use in hospital patient rooms. For one, Section 3.2 defines "residential" as including patient rooms in hospitals. If you believe this, then do you have to model patient rooms in your Baseline model with Residential envelope as defined in Table 5.5-x? This would require one type of Baseline envelope for patient rooms, and another type for non-patient rooms.
And do you have to model the Baseline HVAC systems for patient room thermal blocks using a residential system, such as System 1 or 2 in Table G3.1.1A? The footnotes to Table G3.1.1A do not refer to patient rooms as "residential," but Section 3.2 does. Also, while exception 'a' of G3.1.1 prescribes different Baseline systems for Residential areas (System Type #1 or #2), exception 'c' prescribes that System Type #3 or #4 be used for areas with code-required minimum circulation rates, which pertains to patient rooms as well.
If you believe that it is appropriate for the Baseline to have a Residential HVAC System type, it appears that the Proposed model will be unfairly penalized since G3.1.2.9 does not allow for a Pressure Drop Adjustment 'A' for System Type #1 or #2.
I would appreciate your input and experience as to the appropriate Baseline envelope and HVAC systems to use for patient rooms in hospitals.
Our interpretation would be to follow the residential column for the patient rooms in Table 5.5-x.
Since the note under Table G3.1.1A does not include hospitals in the list of residential facilities, the HVAC should not be #1 or #2 unless any of the exceptions under G3.1.1 apply. Sounds like you might have the option to use either exception "a" or "c" assuming you meet all the requirements. Our interpretation is that would be your choice.
Speaking of Baseline systems in hospitals: I find it interesting that the 'NREL Technical Support Document: 50% Energy Savings Design in Large Hospital Buildings' uses Multi-zone, constant volume, terminal reheat systems as a Baseline, while LEED for Healthcare prescribes that the Baseline be modeled as multiple Single-Zone systems (i.e. System Type #3 or #4).
Hope somebody fixes this before the TSD gets turned into an AEDG...
The prescriptive path in LEED 2009 for Healthcare (November 2011) references the Green Guide for Healthcare V2.2 and describes the HVAC system as follows: "The HVAC system serving all areas shall include Variable Air Volume (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.) air handling units supplied by a central chilled water and boiler plant." This is a System #7. Maybe I am missing something?
Maybe it was my use of the word "prescribes."
You're correct about the prescriptive path in Option 3, Marcus, but I was referring to the Whole-Building Energy Simulation in Option 1, which requires that the Proposed design be compared to a Baseline simulation that uses HVAC system type 3 or 4. I was suggesting that the Baseline in LEED for Healthcare is different than the Baseline used in the AEDG.
Under Option 1 the HVAC system in the baseline is determined by 90.1-2007 Table G3.1.1A and will vary depending upon heating fuel and building size. Perhaps in your specific situation the Baseline is a system 3 or 4 but most hospitals are over 25,000 sf and the baseline would not be either of those system types.
I agree that the baselines can be different. The AEDG was based on a whole series of modeling assumptions so they had to pick a single baseline HVAC system. Under Option 1 the baseline varies depending upon your building design. So the two will not match in many cases. This is one of the differences between a prescriptive approach and a performance approach.
process load
We have currently a LEED NC project of an office building with a data center in the basement. We received the information from the electrical engineer, that the process load of the data center is 190 kW. We believe, that this is the peak load and that the average 24/7 power consumption is far below this value. Does anybody have experience with the relation between peak power and average power of data centers?
One would expect a significant diversity factor in a data center, but without more information about the actual installation, it would be hard to estimate an average.
What is the purpose of the estimate? For an early energy model, I might start by assuming an actual usage of 25% of that peak, but I'd really just be guessing. If you are trying to size equipment, or have a decent estimate of energy consumption, you need more information.
Infiltration rates in LEED Energy Modeling
I am currently doing energy modeling for a LEED Hotel project in Oman. Should I consider the ASHRAE recommended Infiltration rates in all spaces? Is there any LEED Guidelines for Infiltration rates for positively pressurised and neutral pressurised buildings?
Thanks..
As it now stands for LEED the infiltration rate should be identical in the baseline and proposed models. ASHRAE 189.1-2009 established an infiltration value in Normative Appendix B. So I would use this for the baseline. If your building will be tighter then perform an exceptional calculation based on test results for the proposed.
Target Finder
We are building a Hotel in Doha, Qatar. We are try to apply for LEED certified. While I start , I meet a Target Finder problem. This Target Finder only design for US climate. No international 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. was consider. Please advise how should I proceed....
If you are certifying an international project under LEED-NC, you do not need to provide a Target Finder score.
EAp2 - Design and Buildt Contract
Consto have a Design and Buildt Contract with the project owner. The Architects contracts is a part of the contract. His role in the project is design and drawing. Building physics is managed by Consto. In the EA P2 form the architect is suposed to sign for mandatory elments regarding energy. Because these choices not are taken by the architect but by Constos engeeners they feel like not signing. How can we solve this problem? is it ok for Constos engeener to sign?
This pertains to the energy aspects of the building envelope. Who is responsible for ensuring that the project complies with Section 5 of ASHRAE 90.1-2007?
Not sure if this is the same everywhere but in the US a licensed architect must stamp the drawings. The architect is typically responsible for envelope compliance in the local energy code. If this is the case where you are then the architect must sign the form.
If the engineers stamp the drawings with their license on the line and are responsible for the envelope related aspects of the local energy code then they should sign. If they sign there should be a narrative provided explaining why they are signing instead of the architect.
Thank you Marcus. Depending on the kind of contract in the project the responsible for building physics and energy aspects will vary. As for this project we as a building contractor have a design and buildt contract. We are therefore responsible for all aspects on the building.
We will write a narrative to explain around this condition.
LEED NC rating for Non AC buildings
I need expert advise on handling non AC building (naturally ventilated) for applying for LEED NC rating system. The issue is meeting minimum energy performance of 10% over ASHRAE 90.1 2007.
This is very difficult by considering the chillers COP is same for both Base and Proposed case in the energy modelling and take benefits of other energy measures to meet this 10%. This project is a textile factory and the process load is 80% of the total load. This is even more difficult to meet this 10% requirements.
Pls advise us how to handle these projects and this project coming up in Bangladesh
If you are not installing air conditioning in the Proposed building then put air conditioning in both models but set the temperatures in the cooling season so high that the system never comes on.
Since it is a process intensive facility you may need to claim energy savings from the process itself. The procedure to do so has been explained several times within these comments.
Thanks for the reply. I understand that there are no standards available that can be taken as a base case for process energy (like ASHRAE std for non process energy). Is it okay if the manufacturer or owner certifies the base case process energy to compare with the proposed case and demonstrate savings.
Pls let me know your views.
The default assumption is that process loads should be identical in both the baseline and proposed cases for modeling. If you want to claim savings within the process load you need to provide detailed information about your approach, and why you believe the proposed savings is justified. You need to be very clear in you explanation of why the proposed approach is beyond standard practice - if possible show examples of similar buildings using the baseline approach. The bar is purposely set pretty high here - the burden of proof is on you to show that what you propose is better than standard practice.
As Marcus noted, this has been addressed multiple times in this forum. Please read through some of the previous postings.
The manufacturer or owner stating that they feel that the Baseline is standard industry practice doesn't hurt but is insufficient by itself. As Chris says you need to make the case that the Baseline is a reasonable one. Depending on the situation this could entail a rather lengthy explanation and supporting documentation (i.e. studies, research, etc.).
UNUSUAL AND UNIQUE PROCESS LOAD
We are working in a Project which is a unique green energy research facility (the second to be built in the World), and must receive the LEED Silver standard complying with the South Carolina Energy Independence and Sustainable Construction Act 2007.
The Project defines a double Wind Turbine Drive Train Test facility as part of a major renovation on an industrial building.
Part of the building is dedicated to offices, and the other part includes the Test Rigs where Wind Turbine Drive Trains will be tested.
The Test Rigs have a unique energy model, with an energy closed loop of 82% regeneration energy back to the Drive Train motor. Even so, they require a large power supply to both the motor and load application unit. The Total Units of Annual Energy for this process load exceed 9,000,000kWh, with a Peak Demand of 22,500 kW. We would not get to more than a 3% saving for the energy total at the Performance Rating Method Compliance.
For all the Test Rigs area of the building, the temperature control requirement is such of a Technical Room, and only a ventilation system to ensure a maximum temperature of 104ºF is actually needed. This aspect would also affect the number of hour cooling/heating loads not met, which would not comply.
This energy model does not actually relate to any green building practice as compiled at the Leed Reference Guide for Green Building Design and Construction. The unique energy characteristics of the Test Rigs create an inappropriate and disproportionate process load rating to be considered to correctly comply with Section 1.6 – Performance Rating Method Compliance Report under EA Prerequisite 2: Minimum Energy Performance
Our intention is to describe this special circumstance and modelling difficulty as a starting point on the Table EAp2-4, thus not including any process load related to these Test Rigs and their energy closed loop.
We would only include the standard process loads for the general building and its offices area, which are appropriately related to the green building performance.
The following values show the impact of such decision. Baseline energy totals will be substantially modified if process loads are to be included.
The Total Annual Energy Use considering process loads is 37,858,212 kBTU
The Total Annual Energy Use not considering process loads is 3,562,239 kBTU
We have developed Summary reports with both situations to help the analysis of these unusual conditions, and we can forward them to you or include them as a post to help your analysis.
A detailed description of the Test Rigs energy closed loop could be uploaded as a variance narrative under Upload EAp2-8 to document the special circumstance.
Please provide your expert feedback on this modelling difficulty and your guidance on the better way to document and model our project unique characteristics.
All energy use in and associated with the project must be included in the model. There are no exceptions as far as I know and there should not be any including your situation. The magnitude of the process energy use has no bearing. You will need to find a way to show energy savings associated with the process. The good news is that you get to define the baseline.
Review Comments
Maybe this is old news, but I just discovered it, so maybe others haven't yet.
The summary review comments, especially for this credit, come in a nearly illegible no-formatting-in-sight spreadsheet--which has been a headache for our project teams. In LOv3 I found formatted and legible review comments attached to each credit under the "Overview" "Review Snapshot" page. From here you can see all of the review comments by credit (this would be even better if the credits were in order, but this is such an improvement it almost doesn't even matter). You can click to expand each credit which reveals PDFs of the credit form, all uploads associated with that credit, and an html version of the review comments for that credit.
Further making my day, there is also a "download all" button, this means you can now download your entire design (or construction, I assume) review (forms, uploads, and comments) in one fell swoop. This is a super time saver! Now you can just let it download in the background while you do other things, previously you would need to download each form and upload separately.
Emily! Those are great news! I can't find the "download all" button which indeed will save me lots of time. Can you please specify a little more where can I find it?
Thanks a lot!
Daniela,
If you go to the Timeline tab and click on Review Snapshot then you will see the Download All button.
Unmet hours
Dear All,
I am working on a project where the base case is packaged single zone and proposed case has split units. The unmet hours in proposed case is less than 300hours in each zone. But the total works out to be 500 hours. Is the appendix G unmet criteria for whole building or for individual spaces?. I am working on Visual Doe software. Does my project comply with the mandatory requirement of EA P2?
Regards,
Sundararaj
An unmet load hour is an hour where at least 1 zone has loads not met. If 10 zones can't meet their loads at 8AM Monday January 14, that is 1 unmet load hour.
You'll have to look at the model output to see how many unique unmet load hours you have.
I would also verify that your thermostat schedules are compatible with your equipment schedules. Often unmet loads occur when the thermostat schedule calls for heating or cooling, but the equipment is scheduled off.
Both electric heat pump and district energy, what system?
I have a multifamily building which is supplied with heat from both an electric heat pumpA type of heating and/or cooling equipment that draws heat into a building from outside and, during the cooling season, ejects heat from the building to the outside. Heat pumps are vapor-compression refrigeration systems whose indoor/outdoor coils are used reversibly as condensers or evaporators, depending on the need for heating or cooling. In the 2003 CBECS, specific information was collected on whether the heat pump system was a packaged unit, residential-type split system, or individual room heat pump, and whether the heat pump was air source, ground source, or water source. and district energy. How do I choose between system 1 and 2? Which rules do apply? The relation between the purchased electricity and purchased heat is: Electricity 46 % district energy 54 %. (The heat pump has COP=3).
So far I have choosen system 1 since the building isn't classified as electric heated according to the Swedish building code.
Thanks in advanced!
Unless your building is 100% electric, your baseline system must be one of the odd numbered systems in ASHRAE Table G3.1.1.A. If you are purchasing ANY heat, you have purchased heat. So System 1 is the right choice.
I agree that system 1 is the correct choice since your system sounds like a fossil fuel/electric hybrid.
I don't necessarily agree with Chris' 100% electric statement in all cases. The note under Table 3.1.1A indicates that the predominant condition be used if more than one system type applies. Predominant in your case would likely be based on energy use and since your usage is close it would be hybrid and therefore system #1 but a different situation could be a system #2 with some fossil fuel heat.
A couple of other areas to evaluate - G3.1.1(a) outlines a possible exception which allows a secondary system to be modeled and also check out the DES Guidance on USGBC's web site to see if it may help your situation.
http://www.usgbc.org/ShowFile.aspx?DocumentID=7671
FYI - There is a new interpretation - posted 11/1/01 - which is helpful on this. Note that this supercedes some previous rulings - buildings which use gas for morning warmup only, now must be modeled against fossil fuel buildings
11/1/2011 ID# 10132
Ruling
Clarification is requested regarding when a building heat source in Table G3.1.1A should be identified as "Fossil/Electric Hybrid" versus "Electric".
The ASHRAE 90.1-2007 User's Manual states that a fossil/electric hybrid source "refers to a system with any combination of fossil and electric heat, and the baseline system for this is a fossil fuel system". Therefore, the heating source for the proposed building would be considered "Fossil Fuel" or "Fossil/Electric Hybrid" if the building uses any fossil fuel source for space heating (including backup heating or preheating), and the baseline building heat source would be fossil fuel.
Exception: ASHRAE 90.1 Section G3.1.1 Exception (a) stipulates additional system type(s) for non-predominant conditions (i.e. residential/non-residential or heating source) if those conditions apply to more than 20,000 square feet of conditioned floor area.
EXAMPLES OF BASELINE HEATING SOURCE DETERMINATION:
The Baseline heat source from Table G3.1.1A for the following Proposed Case system types would be fossil fuel since the proposed system design includes a combination of fossil and electric heat:
1. Variable air volume system with gas furnace preheat and electric reheat
2. Packaged terminal heat pumps with outside air tempered by fossil fuel furnace
3. Water source heat pumps with fossil fuel boiler
4. Ground source heat pumps with backup fossil fuel boiler
5. 90,000 square feet is conditioned by a variable air volume system with electric reheat, and 10,000 square feet is conditioned with fossil fuel furnaces
The following buildings would be modeled with an additional system type with a different Baseline heating source in accordance with Section G3.1.1 Exception (a):
1. 90,000 square feet is conditioned by a variable air volume system with electric reheat, and 20,000 square feet is conditioned with Packaged DX systems with fossil fuel furnaces. In this case, the 90,000 square feet of area would be modeled with an electric heat source in the Baseline Case (System Type #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 Electric PFP Boxes), and the 20,000 square feet of area would be modeled with a fossil fuel heat source in the Baseline Case (System Type #3 - Packaged Single Zone AC with fossil fuel furnace).
2. 50,000 square feet is conditioned by water source heat pumps with a fossil fuel boiler, and 25,000 square feet is conditioned by electric heat pumps. In this case, the 50,000 square feet of area would be modeled with a fossil fuel heat source in the Baseline Case (System Type #5 - Packaged VAV with hot water reheat), and the 25,000 square feet of area would be modeled with an electric heat source in the Baseline Case (System Type #4 - Packaged Single Zone Heat Pump).
Good to know. Not going after the messanger here . . .
But this is not necessarily how I would interpret the word "predominant" in the note to G3.1.1A. With this interpretation a project could have 99% electric heating and 1% gas and be a hybrid system. So basically I'd be comparing electric heat to gas heat which is what 90.1 goes to great leangths to avoid. Using the term "any" seems to be a very extreme position in my opinion.
Please register to use the forum.