[Bldg-sim] Low-flow Fixtures and LEED

Kendra Tupper ktupper at rmi.org
Wed Jul 1 09:32:43 PDT 2009


You can only take credit for hot water flow fixtures - I typically only
consider restroom lavatories, showers, and dishwashers (assuming clothes
washers may be run with cold water). I use the following procedure for this,
although I'm sure there are other approaches:


   1. Determine all hot water flow fixtures in projects
   2. Create realistic hourly schedules for each distinct usage (i.e. one
   schedule for lavatories, one for showers, one for dishwashers)
   3. Determine peak and baseline gpm for actual design for each distinct
   usage

So in eQUEST, I have 3 separate process loads with different peak gpms and
schedules.

Kendra Tupper, PE, LEED AP
Senior Consultant
Built Environment Team

Rocky Mountain Institute  |  T  303-567-8641 |  F  303-245-7213  |
www.rmi.org


On Wed, Jul 1, 2009 at 10:23 AM, Gregg Liddick
<gliddick at theepstengroup.com>wrote:

>  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® AP
>
>
>
> The Epsten Group, Inc.
>
> 429 Edgewood Avenue
>
> Atlanta GA 30312
>
> Phone: 404-577-0370  ext. 102
>
> Fax: 404-577-1739
>
> www.theepstengroup.com
>
>
>
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> *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® 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® AP
>
> *Mechanical Engineer***
>
> direct: 206.788.4571
>
> cell: 206.354.2721
>
> *www.*rushingco.com <http://www.rushingco.com>
>
> [image: Logo_B&W_1]
>
>
>
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