-
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.
For example, if the project scope 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 connected to a base building ventilation system, then only the VAV boxes would be included. If there are no HVAC components within the project scope, the project is not eligible for the credit....
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.
10 Comments
Computer Room Grade Air Conditioning Units
When utilizing the Core Performance Guide EER ratings I have not been able to find a computer room grade unit that can exceed these EER values. Is this a problem on a lot of projects or can the units be excluded from the EER criteria because they are of a critical nature?
CI 2009 EAc1.3 Optimize Energy Performance - HVAC
Zoning and Controls
Please confirm what is meant by "active controls" for private offices and special occupancies. Does that need to be a seperate 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. box for every single occupancy office or can we meeting the intent of this with some other technology?
Erik Dyrr replied Director, Sustainable Buildings and Operations, KEMA Feb 10 2010
A v2.0 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 and v3 ref guide state..."The system must be capable of modulating AHUs and zone minimum supply volume below 0.30 cfm/sf of supply volume for standard 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. terminals, or below 22.5% of the peak design flow rate for fan-powered VAV boxes. For spaces where the min. outdoor air flow exceeds the min supply volumes specified here, use occupant sensor or DCV to achieve these min supply volumes."
I have taken this to mean all offices must have a vav or be single zone. However, maybe if you have sensors in each office and all offices within a zone report unoccupied the VAV is turned down. I have not submitted in this fashion, but it may work.
Anyone else try this?
Must have VAV system for Option 1?
When we look into the LEED Reference Guide for Option 1, it seems to require a 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 which we do not have (see pg. 168). We can show compliance with ASHRAE 90.1 Mandatory requirements but not the modulating air handling units and not the fan static pressure reset, both of which are features inherent with a VAV system. Is there something we're missing that would still allow us to use the Core Performance Guide efficiency requirements and not have to go to the effort and expense of an energy model?
Erik Dyrr replied Director, Sustainable Buildings and Operations, KEMA Feb 10 2010
Can you inform us of the type of air handling you do have?
The modulating aspect would still apply. If single zone units, then it is an on/off scenario.
Dave Intner replied Firmitas Architecture & Planning Feb 17 2010
Thanks for your reply, Erik.
The project is utilizing constant volume packaged gas/electric units, however, the units are specified with a variable frequency drive (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.) which will allow them to maintain a constant airflow to the space as the filters load up (and their static pressure drop increases). The higher filtration for this project is a result of the space being an OSHPD 3 occupancy.
By an ‘on-off’ scenario, are you talking about the fan shutting off when there is no demand? Due to the code's ventilation requirements, the fan will run when the space is occupied, continuously.
Erik Dyrr replied Director, Sustainable Buildings and Operations, KEMA Feb 17 2010
With a typical constant volume system I don't know how the project could meet the requirements of modulating the airflow. The only option I can think of is to modify the system with zone dampers controlled by occupancy or CO2Carbon dioxide sensors. But this is not likely a feasible option.
Dave Intner replied Firmitas Architecture & Planning Feb 18 2010
Thanks Erik. It seems we're in a situation where code ventilation requirements are trumping opportunities for efficiency.
What if no fan/pump motors are greater than or equal to 5 hp?
Option 1 of this credit states that all motors 5 hp and greater must have VFDs that decrease fan power to 30%. If none of the installed fan motors are 5 hp or greater, can this credit be achieved? Playing with the LEED credit form shows that you must enter something into this section, even if it's not applicable. Additionally, you must enter a percentage 30% or less for 5 points to be documented on the form.
Applicability of CPG sections 2.9 and 3.10
Like Heather's question above, what if the equipment to be installed is less than 5 hp AND doesn't fall under the HVAC equipment categories listed in section 2.9 of the CPG, such as Variable Refrigerant Flow systems? The closest thing might be DX split systems, but this is not an apples-to-apples comparison since this equipment efficiency is regulated by ARI 340/360, yet VRF has no ARI standard, but is generally regarded to be more energy efficient. Can section 2.9 be deemed as not applicable in this case?
Also, what if the new HVAC systems are hydronic fan coils, less than 5 hp, served by an existing chiller and boiler outside the project scope? Can this credit still be achieved by just complying with section 1.4 of the CPG?
Please register to use the forum.