Path for Multi-Family (MF) Weatherization and NC Measures Christian Douglass 8/18/2015

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 2

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) 3

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 calibrationmemo – 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 4

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 5

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 6

Existing Calibration (continued) 7 ReferencePrototypeLocation Heating System Sample Size (n units) Temp setpoints Actual Heat EUI (kWh/yr- ft 2 ) SEEM Heat EUI (kWh/yr- ft 2 ) % Diff # units # bldgs Heat Low (F) Heat High (F) MF MCS Multifamily Metering Study - AAHX Woody Walk- Up Seattle Electric Zonal % MF MCS Multifamily Metering Study Woody Walk- Up Seattle Electric Zonal % ARRA-FG. ARRA Verification - Forest Glen (Ecotope) Woody Walk- Up Redmond Electric Zonal % New MF-2009 Study (Ecotope) Double Loaded Corridor Seattle Electric Zonal % ARRA-AV. ARRA Verification (Ecotope) TownhomesSeattle Electric Zonal % Total Units & Buildings:84030 Avg: % Existing calibration summary:

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 8

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 9

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 10

Discussion? 11 Does the RTF support the CAT’s proposed path forward?

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.” 12

Additional Slides 13

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 14

15 Woody walk-ups:

16 Double Loaded Corridor: Townhouse:

Available Studies MF MCS 1994 – SBW Consulting. “Multifamily Metering Study. Impact Evaluation of the Model Conservation Standards.” Prepared for BPA. April MF Wx – SBW Consulting. “Impact Evaluation of Multifamily Weatherization Program. Program Years ” Prepared for Puget Sound Energy. May 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

Process 1.Use building and operation characteristics of available billing study data – Measured and modeled data compared on an area- normalized basis (kWh/yr/ft 2 ) – A single prototype is selected to match building types in the study data 2.Compare SEEM94 output to billing study results 3.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 18

Results 19

Decision from Sept 2012 Meeting 20 “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