[Bldg-sim] Low-flow Fixtures and LEED

[Gregg Liddick]

Is there a standard for how the savings will be calculated?  The CIR requests that the savings be relative to WEc3, but many of the fixtures contributing to savings in WEc3 do not involve hot water (flush fixtures) and many use hot water only sporadically (lavatories, kitchen sinks, janitor sinks).  I always assumed that was a large part of the reasoning behind not allowing DHW savings.


Best Regards,

Gregg Liddick, EIT, LEED(r) AP

The Epsten Group, Inc.
429 Edgewood Avenue
Atlanta GA 30312
Phone: 404-577-0370  ext. 102
Fax: 404-577-1739
www.theepstengroup.com<http://www.theepstengroup.com>

Please consider the environment before printing this e-mail.

This transmission is intended exclusively for the individual or entity to which it is addressed. This communication may contain information that is confidential, proprietary, privileged or otherwise exempt from disclosure. If you are not the named addressee, you are NOT authorized to read, print, retain, copy or disseminate this communication, its attachments or any part of them. If you have received this communication in error, please notify the sender immediately and delete this communication from all computers. This communication does not form any contractual obligation on behalf of the sender, the sender's employer, or the employer's parent company, affiliates or subsidiaries.



From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Marcus Sheffer
Sent: Wednesday, July 01, 2009 12:18 PM
To: 'Robby Oylear'; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Low-flow Fixtures and LEED

Thanks for pointing that out Robby.  You are correct DHW savings can be counted under EAc1.  As a review firm we have always granted such savings.  As a member of the EA TAG I will ask staff to correct the CIR you referenced.

Marcus Sheffer
7group


From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Robby Oylear
Sent: Wednesday, July 01, 2009 12:12 PM
To: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Low-flow Fixtures and LEED

Forgot to put the CIR in.  Also, I'm just realizing that at the bottom of the CIR it states that addenda have now been approved for use in LEED.  Wouldn't this invalidate #9, as Appendix G addenda a allows for the use of low-flow fixtures?

"4/25/2007 -  Credit Interpretation Request
The adoption of Appendix G under LEED 2.2 raises all sorts of interesting questions with respect to the energy modeling protocol.

Please clarify for us and the world of LEED users out there the following:

1. Appendix G Addendum a
Would USGBC for LEED 2.2 adopt the published Addendum a to 90.1-2004 Appendix G which changes a number of areas?

2. Building Orientation
May we choose to not implement in our baseline model ASHRAE 90.1-2004 Appendix G Table G3.1 5. (a) orientation rotation which requires rotating the model to 4 cardinal directions, and averaging the results. For our project, orientation with the long axis of the building East-West was not optional.

3. Baseline Fenestration Area and Location
Would the USGBC eliminate the provision under ASHRAE 90.1-2004 Appendix G Table G3.1 Baseline 5.(c) that requires dividing out the entire design window area, up to the 40% maximum window to wall ratio, and defining it as horizontal bands with average window to wall area on all facings and floors? This change is also proposed under Addendum a to 90.-2004. The addendum references the section numbering from an earlier version of the Standard prior to the creation of Table G3.1 in the current version of the Standard.

4. Residential Designed Lighting Baseline
Will USGBC for LEED 2.2 adopt the same rules adopted under LEED 2.1 CIR rulings that established a residential lighting baseline, for designed fixed lighting? ASHRAE 90.1-2004 still treats residential living area lighting as exempt (9.1.1 Exception b), and Appendix G does not define a baseline for this lighting. The rulings defined a process of mapping from the designed lighting to baseline lighting with conventional incandescent lighting, with a maximum baseline lighting power density of 2.0 W/s.f. The rulings also established a 750 hour full load equivalent operating schedule to be the same in design and baseline.

5. Residential Receptacle Lighting
Will USGBC for LEED 2.2 accept 90.1 Addendum a) change to table G3.1 Design 6 (d) so that receptable lighting energy usage is not subtracted out from the design and baseline models. This is an inconsistency the addendum corrects, and is the only case where non-regulated energy is not counted under the new standard.

6. Lighting Controls
Will USGBC for LEED 2.2. allow Exceptional Calculations regarding energy savings for occupancy sensor and time-of-day controls that exceed ASHRAE 90.1 code requirements that are greater than the Appendix G Table G3.2. For example, LEED 2.1 rulings appeared to allow greater than 10% allowed by Appendix G for occupancy sensors controlling normally 24 hour interior stair lighting in a multi-family high-rise that would be occupied only a small fraction of the time.

7. Exterior Lighting
Will USGBC for LEED 2.2 allow credit for exterior lighting that is more efficient than the new mandatory provision for exterior lighting in 90.1-2004 section 9.4. Appendix G does not address how exterior lighting should be modeled for the baseline, and therefore the default is that it should be modeled the same as the design and no credit for savings could be taken.

8. Residential Appliances and Exhaust Fans
Will USGBC for LEED 2.2. allow for Energy Star rated appliances and exhaust fans an Exceptional Calculation approach (similar to previous LEED 2.1 rulings for an appliance ID credit) to calculate energy cost savings for EAc1? Exceptional calculation would be based on Energy Star data to define design and baseline energy usage?

9. DHW Usage Reduction
Will USGBC for LEED 2.2. allow the approach to claim domestic hot water energy cost reduction based on low flow fixtures, relative to EPACT standard allowed fixture flows from earlier LEED 2.1 rulings. Another approach would be to adopt 90.1-2004 addendum a) revision to Table 3.1 Baseline 11. labeled as a revision to G4.3 under the older numbering convention.

10. Heat Recovery from Condenser Loop
Will USGBC for LEED 2.2 allow the baseline adjustment for heat recovery from condenser loops to DHW as required in section 6.5.6.2 to be done with assistance of spreadsheet analysis outside of the model, or will the provision at Appendix G Table 3.1 Baseline 11 (f) exception that requires the proposed design to actually include the heat recovery equipment in the real building, if the modeling software cannot model it. The design feature cannot be modeled under DOE-2.2 and its interface eQuest, one of the most widely used and otherwise versatile programs. This provision, if enforced, requires a significant expense for the project that may not be cost effective compared to alternatives. This would be a penalty on the subset of projects that fall under the rules at 6.5.6.2. Normally, the design does not have to meet the prescriptive requirements of ASHRAE, but is allowed to make trade-offs to achieve overall energy cost savings.

11. Solar Hot Water-Clarify Eligibility for EAc1&2
Will USGBC state that solar hot water generation, that does not generate any electricity is eligible for credit under EAc1 and EAc2? Requirements language paragraph 1 for EAc2 does not state if energy generated from a renewable source is electric or thermal, although other parts of the chapter allow for solar hot water, but the second paragraph refers to a method to just estimate electricity generation. Just want to be sure there is no question that solar hot water generation is eligible for both EAc1&2.
  4/25/2007 -  Ruling
[REVISED 10/30/07 to allow energy savings for exterior lighting.]

1. No. Since multiple projects are already in process and the LEED-NC v2.2 Reference Guide specifically mentions that ASHRAE 90.1-2004 is applicable without addenda; any addenda not included in the completed standard will not be accepted at this time.

2. No. The Appendix G method of distributing the glazing equally on all orientations normalizes this issue. The question raised by Appendix G is - Is your building designed to respond to the specific solar orientation?

3. No. See points 1 and 2 above.

4. Yes. The calculation methodology should be considered equivalent for LEED-NC v2.2.

5. The LEED modeling protocol addresses this issue by setting the process load as 25% of total energy by default, unless it is a process dominated building. For a typical residential building, process loads will never be above 25% and therefore should not be an issue.

6. Exceptional Calculation for any measure that is not accounted for in the modeling protocol is accepted on a case-by-case basis.

7. Yes, project teams can take credit for efficient exterior lighting within ASHRAE 90.1 Appendix G. Credit may only be taken for the tradable surfaces listed in ASHRAE 90.1-2004 Table 9.4.5. All other exterior lighting must be modeled identically in the Baseline and Proposed case. The Baseline case exterior lighting power allowance should be calculated using the methodology outline in Section 9.4.5.

8. Yes. Page 184 of the LEED-NC v2.2 Reference Guide describes Exceptional Calculations for residential appliances.

9. No. Credit for saving water is already granted in the Water Efficiency section of the LEED Rating System. The Domestic Hot Water (DHW) loop will be sized for design flows and the PRM does not allow credit for changing loop flows for DHW.

10. No. The requirements for the loop sizing have been set in Appendix G and to maintain integrity of the modeling protocol, such exceptions cannot be taken.

11. Yes. On-site energy generated can be taken credit for using the Exceptional Calculations under EAc1, Optimize Energy Performance, and as percent of total energy for EAc2, On-Site Renewable Energy.


Note: ASHRAE Addenda have been approved for use in LEED projects, as stated on our website: http://www.usgbc.org/ShowFile.aspx?DocumentID=2664"

Robby Oylear, LEED(r) AP
Mechanical Engineer
direct: 206.788.4571
cell: 206.354.2721
www.rushingco.com<http://www.rushingco.com/>

From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Robby Oylear
Sent: Wednesday, July 01, 2009 9:09 AM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Low-flow Fixtures and LEED

Based on a LEED CIR dated 4/25/2007 (see below) domestic hot water savings cannot be claimed for the use of low-flow plumbing fixtures, even though Appendix G addendum a specifically states that credit may be taken through calculations.   Have there been any changes to LEED review methodology since this CIR was released that allows credit to be taken?  Previously we have taken credit for low-flow fixtures and it has been accepted by the reviewer, but have recently come across this CIR which seems to state otherwise.

The reasoning behind not allowing it doesn't make a whole lot of sense.  Water efficiency and energy efficiency are two separate animals, and getting credits under WEc3 Water Use Reduction does not equate to getting energy efficiency credit under EAc1.  It's not like this would be the first time LEED has allowed double dipping (EAc2 Renewable Energy is allowed to be used under EAc1 as well).

Is there a legitimate way to take credit for the energy reduction of low-flow fixtures for LEED?

Robby Oylear, LEED(r) AP
Mechanical Engineer
direct: 206.788.4571
cell: 206.354.2721
www.rushingco.com<http://www.rushingco.com>
[cid:image001.jpg at 01C9FA46.C62AACB0]

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20090701/d1101e5d/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.jpg
Type: image/jpeg
Size: 1804 bytes
Desc: image001.jpg
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20090701/d1101e5d/attachment-0001.jpg>