Path for Multi-Family (MF) Weatherization and NC Measures

Christian Douglass8/18/2015

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Presentation Objective

• Today we are seeking guidance from the RTF on how to proceed with the calibration and updating of MF weatherization (Wx) and ENERGY STAR UES measures– RTF has an existing multi-family calibration that was

approved in 2012– Need to establish whether this calibration is fine or

updates/modifications are necessary– Cannot update MF Wx and ENERGY STAR measures

until a calibration is agreed upon

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Outline for Today

• Status of upcoming MF UES measures• Status of existing MF calibration• CAT proposal on a path forward• Discussion• Sunset Date Extensions (Decision)

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Status of MF UES Measures

• MF Wx – Sunsets in August (seeking an extension today)– RTF’s last Out-of-Compliance (OOC) measure– OOC recommendation memo written in 2010,

prior to existing calibration– Existing calibration was conducted in response to

the Wx memo and was intended to bring measure into compliance• Existing calibration has not been integrated to date, so

measure is still OOC

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Status of MF UES Measures (continued)

• MF ENERGY STAR for new buildings– Also sunsets in August (seeking an extension today)– Unclear whether this could use same existing calibration

• 2012 RTF decision did not specify whether calibration was intended specifically for existing and/or new buildings

• However, it also did not limit use of the calibration to one or the other

– Note: Some of the buildings used in existing calibration were new MF buildings

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Existing MF Calibration

• Developed in 2012 by Ecotope and accepted by the RTF in September of that year

• Uses updated SEEM simulation model• Details of the calibration:– Based on five small MF billing studies from 1994

to 2010 (pre-dates RBSA)– SEEM heating energy calibrated to billing energy

using thermostat adjustment

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Existing Calibration (continued)

Reference Prototype Location Heating System

Sample Size (n units) Temp setpoints Actual

Heat EUI (kWh/yr-

ft2)

SEEM Heat EUI (kWh/yr-

ft2)% Diff#

units#

bldgsHeat

Low (F)Heat

High (F)

MF MCS 1994. Multifamily Metering Study

- AAHXWoody Walk-Up Seattle Electric

Zonal 42 5 68 68 3.02 2.45 -18.8%

MF MCS 1994. Multifamily Metering Study Woody Walk-Up Seattle Electric

Zonal 38 4 68 68 3.02 3.41 13.0%

ARRA-FG. ARRA Verification - Forest Glen

(Ecotope)Woody Walk-Up Redmond Electric

Zonal 40 6 68 68 3.68 3.39 -7.8%

New MF-2009 Study (Ecotope)

Double Loaded Corridor Seattle Electric

Zonal 700 10 68 68 3.08 3.12 1.4%

ARRA-AV. ARRA Verification (Ecotope) Townhomes Seattle Electric

Zonal 20 5 66 66 3.16 3.08 -2.7%

Total Units &

Buildings: 840 30 Avg: 3.19 3.09 -3.0%

Existing calibration summary:

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Limitations of Existing Calibration

• Based on relatively small sample (30 buildings)• Based entirely on Seattle area• Uses coarse T-stat adjustment across all UAs, heating

types, etc. (may or may not be limitation – we don’t know)

• Never used to compare to savings, or separate estimates of pre- and post-measure consumption– We will soon have the ability to do this – working to get

billing data from Seattle City Light

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CAT Proposal

• Although there are limitations to existing calibration, no reason to believe it is insufficient

• However, given recent RTF decisions on SF and MH calibrations, seems prudent to compare to pre-/post- data

• CAT proposes comparing existing calibration to Seattle City Light pre-/post- dataset

• If comparison checks out, continue to use existing calibration

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Why not use RBSA?!?• RTF’s SF and MH calibrations now based on 2012 RBSA

dataset• RBSA has MF data as well – problem solved!• Not so fast…

– Although RBSA MF dataset looks large (~230 buildings), necessary calibration filters could reduce this significantly

– RBSA calibrations for SF and MH have proven to be very large lifts

– Unlike SF and MH, MF dataset does not have heating energy estimate readily available (only total energy)

– RBSA is observational dataset – would still want to do pre-/post-comparison anyway

– In short, this may be an option, but a resource intensive one

• For all these reasons, CAT proposes testing the existing calibration first

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Discussion?

• Does the RTF support the CAT’s proposed path forward?

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Sunset Date Extension Decisions

“I _________ move that the RTF extend the sunset dates for the following UES measures to December 31, 2015:– Residential Weatherization – Multi-Family– Residential New Construction – ENERGY STAR

Homes Multi-Family.”

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Additional Slides

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Existing Calibration Background

• Constrained to multi-family buildings three stories or less.

• Building types and prototypes:– Townhouse

• Exterior access; shared walls

– Woody walk-up• Exterior access; stacked flats; shared walls, floors, & ceilings

– Double loaded corridor• Interior access; stacked flats; shared walls, floors, & ceilings

15Woody walk-ups:

16Double Loaded Corridor:

Townhouse:

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Available Studies• MF MCS 1994

– SBW Consulting. “Multifamily Metering Study. Impact Evaluation of the Model Conservation Standards.” Prepared for BPA. April 1994.

• MF Wx 2007-2009– SBW Consulting. “Impact Evaluation of Multifamily Weatherization

Program. Program Years 2007-2009.” Prepared for Puget Sound Energy. May 2011.

• New MF 2009– Heller, Geraghty, and Oram, Ecotope. “Multifamily Billing Analysis - New

Mid-Rise Buildings in Seattle.” December 2009• ARRA-FG and ARRA-AV

– Ecotope for King County House Authority. ARRA Verification Project. 2010.

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Process

1. Use building and operation characteristics of available billing study data– Measured and modeled data compared on an area-normalized

basis (kWh/yr/ft2 )– A single prototype is selected to match building types in the

study data

2. Compare SEEM94 output to billing study results3. Adjust input parameters only as appropriate

– For example, cannot adjust insulation levels if they were definitively provided in the billings study.

– Planned to adjust heating setpoint (within reason).

4. Compare again

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Results

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Decision from Sept 2012 Meeting

“Accept the use of SEEM 94 as calibrated for space heat energy consumption in multi-family buildings, 3 stories and less, when using the RTF’s prototypes and a thermostat setting of 68°F for the walk-up and corridor buildings and 66°F for townhouses (independent of heating system type).”

Motion passed with 21 votes in favor, none opposed