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What’s in your scope
This credit requires that you demonstrate energy savings from HVAC systems and components within your project scope—only systems installed as part of the LEED-CI project, or systems within the LEED boundary. (See more detail on scope below.)
Two options, for up to ten points
There are two options for achieving this credit, either of which could earn five or ten points for your project.
- Option 1 uses a prescriptive approach. You earn five points for calculating building loads and meeting mechanical system efficiency requirements in accordance with the Advanced Buildings: Core Performance Guide (CPG), Sections 1.4, 2.9, and 3.10. You can also, separately or in addition, earn five points by demonstrating appropriate zoning and controls to promote energy...
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.
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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.
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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.
128 Comments
ASHRAE 55 requirement in EAc1.3
Does anyone knows if ASHRAE 55 is really a requirement for the credit? There is an clarification on CI v2.0 (issued June 17, 2011) that states about equipament efficiency indicated in ..."sections 2.4 (less ASHRAE Standard 55)"....
It is still considering the old E-Benchmark as it is a clarification to LEEC-CI v2.0, however I consider that would be the same for v2009. Besides that ASHRAE 55 is already required for IEQc7, so if a project do not comply with the standard, both credits are not elligible for the project. Does anyone had experience on that?
Tks
Determining Baseline System Type
I am trying to correctly determine the baseline system for my LEED energy model. I have a 7-story hotel building so it will either be System 1- PTAC or System 2 –PTHP based on ASHRAE 90.1-2007. The major difference between these is using gas vs. electric for heating. The proposed design will use VRVs. The most accurate comparison using just this information would be System 2-PTHP since the VRVs use electric. However, there are instances where we will use gas such as for domestic hot water and a small lobby portion of the building which will have a separate RTU. These instances are not indicative of the majority of the building, but does the baseline system need to be System 1-PTAC because of this use of gas?
The interpretation ruling below was posted on 11/1/11. If your project was registered before that date I would suggest it is appropriate to model a system 2 in the guest rooms and a system 3 for the lobby area. Make sure to explain this in your narrative. If not yet registered by that date then it looks like the whole building should be a system 1.
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).
Bypaas VAVs and AHUs
Hello to all, my query is our project is two floors in a 9 floor building. The base building developer has provided AHUs and chilled water supply. In our project we have installed bypass type 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 with thermostate control only in meeting rooms and cabins but rest of workstation area is without VAV boxes. I want to know how can we model this system in simulation because bypass VAVs do not have pressure sensitive controls, it has temperature sensor controls.
Questions related to how to model a particular system vary depending on the software you are using. Perhaps you should post your question to the appropriate group in the following web site.
http://onebuilding.org/
Table EAc1.3-2
Are we to include lighting and small power line items in this table and electrical equipment for a data center? The table lists "HVAC" energy uses which these are not, but ASHRAE 90.1 and our modelling software suggest we should include these items.
Looks like you would only need to include heating, cooling, fans and pumps, and other HVAC in this table on the credit form.
VAV system required for small DX?
I am researching option 1 for Advanced building requirements. We are working in a 1 story industrial park and are installing new 10 ton and below DX RTUs. We are meeting all the efficiency requirements, but I am uncertain if 3.10 Variable Speed requires VRV system? Or is a constant volumn DX RTU design acceptable?
If your individual unit fan motor horsepower is greater than 5 hp then you would need to comply with 3.10. If less than 5 hp make sure to point that out in your documentation.
LEED Interpretation on Min HVAC and Zoning Reqs
Hi everyone -
I just wanted to let you know that there are two new LEED Interpretations out clarifying the minimum HVAC scope and zoning as it applies to private offices. The Interpretations Database can be found here: https://www.usgbc.org/leedinterpretations
Thanks!
Amy
sorry, I find that link useless for this credit -can not search to find the interpretations you refer to.
If you go to the LEED Interpretations site, choose "LEED Interpretations", "Commerical Interiors v2009", "Energy and Atmosphere", "EAc1.3: Optimize Energy Performance", it will return 5 total Interpretations, including the two referenced above., # 10134 and #10135.
Amy, thanks for noting these Interpretations. I have summarized their key points in the Bird's Eye View tab above for convenience.
thanks Tristan
Energy Modeling for a project space within a larger building
I have a small dental office project that is located in a larger residential tower. The space is being conditioned by two water source heat pumps located in the space. The heat source for these water source heat pumps is the condensate water loop from the building, which is rarely, if ever, being treated by the building's central system. This condensate water loop is the only connection to the building's central system, and the heat pump's are doing pretty much all of the work conditioning the system. Do I have to model the entire building, or can i model just the project space?
Thanks,
Jake
Hi Jake,
I think you will probably have to model the building system. However, you should first read through Treatment of District or Campus Thermal Energy in LEED v2 and LEED 2009 – Design & Construction, which may offer some more concrete guidance.
EAc1.3 A - Equipment Efficiency
I recently completed a CI in an old building with a constant volume Interior and console heat pumps on the perimeter. As a result to achieve points under the credit EAc1.3, the prescriptive criteria option was utilized for equipment effeciency which adhered to the Core performance guide. The project was submitted and all supplemental units met the criteria, which as my understanding was project scope of work, and all that needed to pass. Below is a respond from the reviewer which is unique to any interpretation I have seen before.
"1.All HVAC equipment installed as part of the scope of work satisfies the relevant Core Performance Guide requirements AND the project scope of work includes either of the following: a) Air handlers with Variable Speed Controls complying with the requirements of the Core Performance Guide Section 3.10 and supply at least 60% of the total supply air volume used within the project scope, OR b) Mechanical equipment complying with the prescriptive efficiency requirements of the Core Performance Guide Section 2.9 that provides at least 60% of the cooling or heating capacity for the project scope. 2. The relevant criteria from the Core Performance Guide has been met for all HVAC systems serving the area within the project scope, whether or not the HVAC systems are installed as part of the tenant scope of work."
Has a new addendum been sent out by the USGBC regarding this credit? I haven't found anything in the reference guide or recent addendums to suggest the interpretation of this credit has changed to include equipment that's 60% of the project. Has anyone else seen a review like this? Would a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide be worth the time and money? Thank you.
Let me further clarify the question: The fact that 60% of total supply volume needing to satisfy the core performance guide criteria even though it's existing base-building systems has never been as aspect of attaining this credit. It has only been tenant installed systems, and that part is what I'm looking into. Thank you for your time.
Geoffrey, this won't be of much help, but I have just received the same feedback and it completely baffled me. I had a project last year, which - in addition to the 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, diffusersIn an HVAC context, diffusers disperse heating, cooling, or ventilation air as it enters a room, ideally preventing uncomfortable direct currents and in many cases, reducing energy costs and improving indoor air quality (IAQ). In light fixtures, diffusers filter and disperse light., etc - had some stand-alone A/C units for the comms rooms. The reviewers agrees that the A/C unit was enough scope to qualify and awarded us the five credits for equipment efficiency.
Now, for a very similar project I get the same answer as you did above, requiring 60% of the heating or cooling load to be met by the mechanical equipment. This requirement is not in the Ref Guide and not in any of the addenda and contradicts the decision I received for pretty much the same project a year ago.
Does anyone have an idea what is going on? Has this requirement been published anywhere?
Geoffrey, I put a question to the GBCI on this and apparently they published a "clarification" on the subject in June. http://www.usgbc.org/ShowFile.aspx?DocumentID=9603
Note that it's not on the CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide database, not mentioned on this site, and I have not received anything from the USGBC in a newsletter, so I'm not sure just how one was supposed to find out about it.
Also, because it's a "clarification", not an addendum, it is not a change to the system, i.e. it applies to all projects, whether they had been registered before this "clarification" (i.e. to you and me, a change).
Adele, thank you for your time. I too reached out and received the same clarification. It appears now not only do all installed systems have to meet the criteria, but a majority of HVAC capacity has to either meet eitehr section 2.6 or 2.5.
Typically these changes are communicated during the LEED process, and area I would like to se changed as well. Thank you again.
Thanks for the good dialogue on this. We also received the same review comment, having never seen this clarification either. Thank you for the link. Yet another silly and obscure update contradicting the reference guide...
Wouldn't it be great if the Review Team spent an hour with us BEFORE hand to say what they want to see rather than all this going back and forth wasting everyone's time.......I have this very same conflict of information on this very same credit, our reviewer has not mentioned this "clarification" yet.....
I completely agree with Sue on this. It's becoming a bit of a farce that after passing two LEED AP exams and practically memorizing the Reference Guide, I have to check interpretations for every credit for each project, just in case there has been an update that suddenly requires something completely different (case in point EAc1.3). Even when you've done all this (why can't they just revise the Ref Guide instead?), the reviewers still manage to surprise you by pulling out a practically unpublished "clarification" that changes the whole picture and makes you look like a complete idiot to the design team.
I also think that clarifications like these that occur within the same rating system can hurt the credibility of LEED in the long run. Prior to the EAc1.3 clarification I had a project certified Platinum with just barely over 80 points, where we got 5 points for the equipment efficiency credit, even though there was one single split A/C unit in scope. Now, of course we would not get these five credits, because the clarification states that there would not be enough scope and therefore the project would only get Gold. The fact that this can happen within the same LEED-CI 2009 system is somewhat concerning.
FYI, I was just reading about this:
https://www.usgbc.org/leedinterpretations
"All project teams are required to adhere to all LEED Interpretations and Addenda posted BEFORE their registration date. Adherence to rulings posted after a project registers is optional, but is strongly encouraged."
We are following option 1 for
We are following option 1 for equipment efficiency .The project is 1 floor in a 17 storey office building.The ONLINE form shows the following requirements:
-Load calculations
- Fan-sizing and zone-by-zone load calculations
- Critical path supply duct pressure loss calculations
- Part-load condition calculations
The scope of work for HVAC in the project includes only 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 as the AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition) 2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork.'s are pre-installed by building owner. I am not sure what kind of documentation is required for compliance.
Also, the sample calculation provided under documentation toolkit LEEDUSER - HVAC Load Calculation for Option 1 seems to be from an energy modelling software.Do we really need to provide such detailed calculations if we are pursuing option 1?
Please advice.
baseline model in LEED certified building
Dear Paul
We have a project thats occupied above 70 percent of a base building.The base building is going for LEED CS Gold.
this tenant fit out project is going for LEED CI. For energy modelling work, is the baseline for the LEED CI Option 2 consist of ' the proposed parameters in the existing basebuilding' or the baseline is based on ASHRAE 90. 1 alone
What is mean is to demonstrate 15 percent saving, is it 15 percent over the base building (LEEDCS ) energy consumption or is it 15 percent over the basebuilding modelled with ASHRAE value alone
please clarify
thanks in advance
Puteri, as stated in the credit language (see the tab above), the 15% savings are relvative to ASHRAE 90.1, not to the core and shell building.
LEED USGBC REVIEWS
Hi Group
i wanted some advise on how the reviews happen at USGBC .
Actually for one of our LEED CI projects we recieved certain
clarifications to be provided for the HVAC credit which we provided
in all clarity and correctness still in the final review the credit has been
denied and the reviewer has sent word to word the same reasons as were
in the eralier phase . We see that it is not right , can you please advise
as to what can be done for it apart from appeal and do these things
happen occasionally as it is not acceptable to deny credits without
correct reasoninig and we depend a lot on these energy credits .
Shuchita,
We feel your pain! GBCI review teams are often inconsistent in their reviews. You can try emailing your review team with a direct question, providing them plenty of detail about the earlier projects where you achieved the credit with the same strategies. If that doesn't work, appeal is probably your best option (though it's an unattractive option because it costs money and can take a while!). A different review team will look at your appeal, so your chances of getting the credit will hopefully go up.
I see you posted this awhile ago, so please let us know how it turned out for you!
Is the ENERGY STAR Equipment Table from EAP2 connected to EAC1.3
I do not believe any of the new equipment in the project I'm woking on is covered by the energy star rating system.The project space is a museum hall that contains one new chilled water AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition) 2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork. and 3 new chilled water blower coils. We are tapping into the existing basebuilding chilled water lines. There is no other additional equipment in this project. If I do not fill out the Energy Star Rated Equipment table in EAP2, will I still be able to show compliance with EAC1.3?
"active controls"
Has the USGBC/ GBCI ever defined requirements to meet or even define what "active controls capable of sensing space use and modulating the HVAC system in response to space demand"? There are multiple threads on this page asking this in a round-about way, but specifically what is eligible other than an occupancy sensor- i.e,, thermostats, manual overrides, etc.
Savings calculations
Our client is occupying the 8th floor of a G+8 building. The central plant is a combination of Air cooled and water cooled chillers. The conditioned area of the project area alone is 45,000 sqft and segment area is 322,000 sqft. I simulated using the project area-segment area method. I used the existing conditions for segment area in both base case and proposed case. I modeled the project area as per ASHRAE 90.1 2007. Now the problem is with the savings calculation. As per LEED, the formula is (Base case-Proposed Case)/(Base case*(project area/segment area)). Since the project is occupying only 1 floor, the project area/ segment area ratio comes up to 0.139 and because of this the savings goes higher than 100%. In other words, we will be multiplying the savings by 7 times if we calculate the savings by the usual formula, (Base case- Proposed case)/base case. Kindly guide how to proceed. Thank you
Sundararaj,
This is a very interesting case, but can I ask where you got that equation? It doesn't seem like it should work, because in CI, your project area would always be much less than your segment area. You may want to check that the formula is applied properly. Also, if you link to where you found it, we can go through it together.
Paul
Sundararaj,
Your formula is correct. Because your building is served by a central plant, the entire building must be modeled. Did you model the floors outside of your project area as existing for both proposed and baseline cases? This would mean that the central plant, lighting, systems, etc. is modeled identically in both cases for all floors excluding the project area. Because you are modeling the entire building, your segment area would be the total building floor area.
Then, with your formula only accounting for cooling, heating, and fans/pumps you shouldn't see something in excess of 100%. I have reviewed some energy models that were incorrectly applying ASHRAE baseline systems to areas outside of the project area.
Thank you for the reply. The formula is in page 172 EA cr 1.3 of LEED Reference Guide for Green Interior Design and Construction, 2009 Edition.
As per the reference guide, i have modeled the entire portion of the building sharing the central plant. Project area is the Eighth floor of 44,734 sqft conditioned area. The segment area is from 1st floor to 7th floor of 322,373 conditioned area. I have considered identical parameters (i.e. existing conditions) for segment area in both base case and proposed case. The savings calculations are done excluding the lighting and equipment load and considering only the HVAC loads. Also, the Base case as per ASHRAE 90.1 2007 is Packaged variable air volume system for project area. Project area is fully modeled as per ASHRAE 90.1 2007. The HVAC Energy consumption in base case is 2,353,462 KWHA kilowatt-hour is a unit of work or energy, measured as 1 kilowatt (1,000 watts) of power expended for 1 hour. One kWh is equivalent to 3,412 Btu. and proposed case is 1,787,825 KWH. Project conditioned area/segment conditioned area = 0.138. I have considered the segment area from 1st floor to 7th floor and have not included the 8th floor which is the project area. The savings achieved with the above results would be 178% which is not logical. Kindly help.
We are working on a couple of projects of this kind and again the savings achieved is high. But not going beyond 100%. However, i want to know whether the methodology for savings calculation is correct. Also, requesting you to give a solution for the previous post (regarding 178% savings).
Option 1
I'm working on an existing Building. the original building has its gold certificate CS and all main 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. roof top units are installed originally at 2008. Now we have project at second floor of this building. this area has seperate units and we are providing DDC control for all areas. we can get 5 points for zoning and control but my question is, is it possible to get 5 other points for HVAC efficiency since the units are not installed under our project but as i said the entier building has gold LEED certificate.
Thanks,
Azita
Azita,
If you wish to claim the efficiency of the HVAC units, then you have to include it in your scope of work. That is to say that if you claim credit for them here, then all LEED credits that might be impacted by those HVAC units must account for them.
Hope this helps,
Paul
thermostat = space sensing occupancy?
EA 1.3 Option B. I have gotten inconsistent reviews over separate projects on thermostat controlled 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. Is thermostat sensitive enough to fulfill 'space-sensing' requirement or do I have to use a motion controlled VAV box? In some tenant spaces, VAV system is controlled by DDC, and in turn by building BMS. We are not allowed to alter the building BMS, so basically we cannot alter existing VAV boxes by adding motion sensing capability.
I know of a couple projects have been approved using thermostats but my latest one has been selected for clarification due to thermostats not fulfilling ' space sensing' requirement.
So far as I'm aware, DDC thermostats fulfill this requirement. Again though, different reviewers look at different things. Inconsistency is pretty much the norm. My advice is to submit with Thermostats and if the reviewer asks for a change, deal with it then. Otherwise, your other option is to submit a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide to get a ruling from the EA TAGLEED Technical Advisory Group (TAG): Subcommittees that consist of industry experts who assist in developing credit interpretations and technical improvements to the LEED system., which would set the standard for all projects.
Paul
Treatment of DES for LEED-CI 2009
I am working on a project to build-out the 2nd floor of a 2-story law school building, approximately 9,000 square feet for each floor. The building's HVAC systems are served by a central heating and cooling plant that also serves many other buildings.
I was reading through USGBC's Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design and Construction and the only mention to LEED CI is to refer to Appendix A.
Appendix A states for LEED-CI that "District Energy Systems have no effect on any EA section prerequisites or credits. Any effects of the District Energy Systems shall be picked up by SS Credit 1, Site Selection, under one of the following paths..."
So my question is, what do I model for the baseline and proposed cases in my energy model? I am modeling the entire building because there is a separate ventilation air preconditioning unit serving all building AHUs, which means I am affecting the performance of a system that serves the entire building. I fall under System 3 for my baseline case according to Appendix G for the whole building. What does this Appendix A mean? Do I model both cases as purchased chilled water and purchased steam?
I was prepared to obtain the metered kW/ton values for the entire plant for my virtual DES in the energy model until I came across this Appendix A (I've done many NC models, but this is my first CI model).
Jason,
Your safest bet is to model it exactly as though you would an NC District Thermal Energy System, then isolate the portion of the building that is being built out and compare that. I realize that this is a lot of work, but it's the method that is most likely to get approved by a reviewer.
I would recommend against trying to model it in some other fashion, unless you submit a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide to get clarification on what the EA TAGLEED Technical Advisory Group (TAG): Subcommittees that consist of industry experts who assist in developing credit interpretations and technical improvements to the LEED system. would like to do in this situation.
Paul
Thanks Paul, I was going to do exactly what you stated in the first part of your response, until I came across that Appendix A that solely address LEED CI 2009.
I just don't know what USGBC's intent was when developing this Appendix A. Something has to be modeled for my cooling and heating sources along with a utility rate, but this is unclear according to their Treatment of DES document.
EAc1.3 and onsite renewables
Can we take credit for PVs? If so, how do you include the savings? If we include the PVs in our energy model, the savings is deducted from the total building end use. The LEED template table for Path 2 has the end use broken out into specific categories.
Shannon,
I've honestly never come across a CI project that tried to incorporate PV. With no specific credit for on-site renewable energy in the Commercial Interiors rating system, as a reviewer I'd be reluctant to allow the project team to claim credit for on-site renewables. The reasoning is that CI is primarily a rating system which relates to how spaces are built-out, not how a whole building functions.
I would say, however, that if you wish to claim credit for a PV system in your CI project, that your best recourse is to claim it as an ID credit. Your other option is to submit a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide to the EA TAGLEED Technical Advisory Group (TAG): Subcommittees that consist of industry experts who assist in developing credit interpretations and technical improvements to the LEED system. and see how they wish to incorporate it.
Regards,
Paul
Energy Simulation for CI
My client is hiring only a small portion of the existing building, which is not LEED certified, and we are using the common central chiller of that building, but we have our own AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition) 2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork., we have also installed 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.'s for all individual spaces within our space.
Now for achieving the EAc1.3; When we opt the Option2, with Energy Cost Budget method, What do we need to model for the Design and the Baseline case?
We only have detail information about the tenant space and the whole building envelope, but not the whole building's air side, occupancy, lighting and plug loads etc.
You only need to model your portion of the building, not the entire thing. You can model it as a "virtual" building, that is to say, as though your portion of the building is all that exists. Use ASHRAE 90.1 Appendix G as your reference to build up the baseline. I would use the whole building numbers to choose the correct HVAC System (ergo if your space is 50,000 sq ft but the whole building is 250,000 sq ft, use 250,000 to find the correct HVAC System). Once that's complete model your space as it actually exists and use the actual HVAC system from the building. Compare the two in the EAc1.3 form and you should be good.
Dear Paul, Thanks for your reply, but in Option2 (comparison with ASHRAE) its stated that
"The simulation should generally involve more than just the project space and model the building segment that is served by the common HVAC system. For example if the project area takes up the third floor of a 5-story building and the building has a single central plant, the entire building should be modeled."
Pl clarify this. Thanks again.
I apologize Santhosh, I didn't see that you'd responded.
The answer is "it depends". You need to be able to isolate your portion of the building from the rest. There are methodologies for doing so, but depending on your software, it can be more or less difficult. In eQUEST, for example, you can manually set up individual electric meters and then indicate which meters you want to report on, but to do so, you must be in detailed edit mode and know the in's and out's of the software.
Conversely, if you include in your narrative why you only modeled your portion of the building, a reviewer is much more likely to accept your project.
Hope this helps,
Paul
Option 2 - Server cooling
In our CI-project (2 floors of office space) we want to go for option 2. But we are not sure if we have to include the installed load for cooling the server room into the the total tenant space loading calculation for cooling the indoor air. Could you give an advice please?
The installed load for the cooling of a server room/data center is considered process energy. Depending on your software, you can call it a misc load, or something of that nature. The amount of energy should be identical in the proposed and baseline models, unless you use an exceptional calculation methodology. (Which makes life significantly more difficult.
Option 1 Equipment Efficiency - more questions
We have two project pursuing the prescriptive option and each one has issues:
1. A tenant is taking all of an existing buildng and adding a VRF system to supplement the existing system (rooftop package units) because of a higher occupant load than the base building system was designed for. From previous comments, it sounds like a VRF system does not fit well into the CPG criteria because of a lack of testing procedures. I am wondering though about the last bullet in the summary of section 2.9 which says "Equipment not listed shall meet the Energy Star criteria where applicable". Energy Star does have performance criteria for VRF systems using a relatively new testing procedure - AHRI 1230. Our equipment meets the Energy Star standard and is tested in accordance with AHRI 1230. Will this work to meet the Mechanical Equipment Efficiency section?
2. The other project is a tenant taking a small portion of a large building. The only new HVAC equipment will be a WSHP to cool a server room which will tie into the existing HVAC water loop. The equipment is 8 tons and the EER is 13.7 at 85 degrees F EWT, which does not meet table 2.9.2 requirement of 14 EER. The 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. manufacturer claims that the efficiency will actually be 14.0 EER based on the fact that our building water loop is 80 degrees F EWT. The engineer also insists that this will meet the requirement. It was my understanding that the equipment had to meet the efficiency requirement at the standard rating condition of 85 degrees EWT and since the equipment is 13.7 EER at that condition the equipment does not comply with the standard. Can someone clear this up?
Whew, Nancy, that's a complicated set of questions!
1) Assuming that the VRF system in questions meets the standards of the new Test procedure, and you include the documentation in the EAc1.3 submittal, my feeling is that a reviewer would probably accept that. Different reviewers may have differing opinions, but if you have the documentation it'll be difficult to find a reason to deny it.
2) The equipment must meet the efficiency requirement at ARI conditions, ergo the system in question more than likely will not qualify.
Thanks Paul,
Glad I was not able to stump you.
Haha, glad to help.
Option 1 - Equipment Efficiency
We have a new build out of a small office in an existing industrial building. We will be adding new package roof top units with DX cooling and gas heat to condition the office space. We are pursing the equipment efficiency portion of Option 1. Section 2.9 of the Core Performance Guides lists package units but the efficiency requirements are for cooling only. Gas furnaces are mentioned under a separate bullet with gas unit heaters. Do we just need to meet the efficiency requirements of the package unit bullet or do we also need to meet the gas furnace requirement?
Nancy,
You'll need to meet the requirements for both heating and cooling.
OK. Thanks.
description of the potential savings
I recently recieved a review comment asking to expand the narritive of EAc1.3 Opt. 1 to include "description of the potential savings" as requested on the credit template. I am attempting only the 5 points for appropriate zoning (part 2 of option 1).
How in depth does this potential savings description need to be? Does it need to include the results of an energy model? Are there other forms I should upload?
Jacob,
I apologize for not seeing your question earlier. From your description, I would say it doesn't need to include the results of an energy model. It does, however, need to give the reviewer a relatively clear understanding of how your building meets the requirements of the "appropriate zoning" requirements. I don't believe that there are any "savings calculations" involved based on the description you've provided, and I'd respond to the comment that you don't believe there are any savings to be calculated, but here is the detailed manner in which your building is meeting the requirements of Option 1.
If this seems totally off base, then I may need to look at more of your actual project to get a good feel for it.
description of the potential savings
I recently recieved a review comment asking to expand the narritive of EAc1.3 Opt. 1 to include "description of the potential savings" as requested on the credit template. I am attempting only the 5 points for appropriate zoning (part 2 of option 1).
How in depth does this potential savings description need to be? Does it need to include the results of an energy model? Are there other forms I should upload?
Jacob,
It seems very strange for a reviewer to ask you for a "description of potential savings" on a prescriptive project. Was it directed at a specific aspect of your option 1 template?
Without having very many details of your project, I would recommend providing a narrative describing how the prescriptive actions you've take will save energy over a minimum compliant ASHRAE 90.1 Appendix G system, but I would not make specific calculations or build an energy model, as that is beyond the scope of Option 1, which I would re-iterate politely in the narrative.
Paul,
Thanks for the responce. The coment was directed at the narritive section of the template that says:
"Describe the HVAC system serving the tenant space as well as the building-level system. Explain how the zones were determined, the control logic, and the potential energy savings"
The reviewer said simply:
TECHNICAL ADVICE:
Please provide a narrative description of the potential savings that are achievable with the system design.
The reviewer also mentioned that I had fulfilled the requirements of the rest of the narritive. I think you are right about a short paragraph without calculations.
Jacob,
Yeah I think that'll be sufficient! Good luck!
That must be a standard cut and paste comment, because I have the same exact words on my review, also taking the prescriptive route. I decided they weren't looking for dollars or kwhA kilowatt-hour is a unit of work or energy, measured as 1 kilowatt (1,000 watts) of power expended for 1 hour. One kWh is equivalent to 3,412 Btu. saved, but just a better description of how I am controlling the system to minimize unnecessary energy use. (eg. this is my demand control ventilation strategy and I expect it to save energy because it reduces the ventilation load at the equipment serving spaces with transient occupant loads.) I guess I will find out soon enough if that was what they were looking for.
VRV system how to take 5 point for equipment efficiency
I am working on a small office space. I am trying to get 5 points for equipment efficiency. And the AC、Fresh air system is VRV(variable refrigerant volume),The ac outdoor unit cooling capacity 106.5KW,the cooling power:30.6KW,Other ac outdoor unit cooling capacity 11.2KW,cooling power:3.0KW,
The fresh air outdoor cooling capacity:40KW,cooling power:12.4KW,The fresh air indoor unit power is:0.359KW,and the other is 0.548KW.
All the refrigerant is R410A.
The office was 5F、6F floor of 6 story,Use area of 500 square meters.
Xiao, I'm not sure what the question is here, can you provide more context?
Baseline design by Appendix G
I am doing energy model for LEED for Interiors 2009.
We work on a project that occupies 2 floors of a 7-story building. The
building has already got LEED for Core and Shell . Energy model of the
building was done using ASHRAE 90.1 2004 Appendix G. I am
using Appendix G of ASHRAE 90.1 2007 for LEED for interiors.
If my project has common HVAC system with other floors, how does the
model look for the baseline case? Do I have to model 2 stories of the
building ( my project) as a stand-alone building by AHSRAE 90.1 2007 and
other floors have to be modeled by AHSRAE 90.1 2004 ?
If I don't have enough information from Core and Shell design, can I use
only two alternatives ( actual and baseline design) for submission or I
have to submit 3 alternatives in any case?
Thank you,
Evgenia,
I would use the model you already have, and pro-rate the amount of energy used by your floors in comparison to the entire building. If your modeling person can isolate the energy used by your two floors, that would be even better. Energy models in LEED for Interiors are technically only concerned with the area that's within your project scope and not the entire building.
Paul
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