Ben Larson28 September 2010

Ben@ecotope.com4056 9th Avenue NE, Seattle, WA 98105(206) 322-3753 Fax: (206) 325-7270

Background: New Oregon residential energy code proposal

analysis. The OR-BCD has asked Ecotope and the RTF to produce a savings estimate.

Goals Today: Present and discuss methodology Introduce proposed code changes Obtain approval of methodology

Next Meeting: Present results

2

Code revision goal is to reduce whole-house energy use by 10% over the 2008 code.

Code covers single family detached and multi-family dwellings 3 stories or shorter.

3

Determine representative characteristics of housing population including: Climates Single Family (SF) and Multifamily (MF) occupancies HVAC systems Prototype buildings

Compile base case and proposed code requirements

Calculate annual energy use for the representative housing population. End uses considered include: Heating, Cooling, Ventilation, Lighting, DHW, and MELs

Weight calculation outputs together based on housing population data

4

Data used for the weightings include census information for housing starts by county and regional baseline studies Census data: http://censtats.census.gov/bldg/bldgprmt.shtml

Two most relevant sources are the NEEA 2007 residential regional baselines for single and multi-family prepared by RLW.▪ Single Family: http://www.nwalliance.org/research/reports/168.pdf

▪ Multifamily: http://www.nwalliance.org/research/reports/07%20173.pdf

5

Use three representative TMY3 sites for Oregon

Building permit data by county from 2004-2009 gives the following weightings. Counties with like climates were

collapsed onto one the three climate types.

City HDD65 CDD65 Weight

Portland 4187 367 0.78

Redmond

6583 204 0.15

Medford 4530 601 0.076

Housing start data also gives SF to MF breakdown by county (and climate)

Climate Weight

Fraction Within Climate

(Climate Weight ) x

(SF or MF Weight)

(from previous

slide)

Single Multi Single Multi

Portland 0.78 0.75 0.25 0.59 0.19Redmond 0.15 0.94 0.06 0.15 0.01Medford 0.07 0.93 0.07 0.06 0.01

State Average 0.79 0.21

7

Single Family: 1344ft2 – Single story over crawl space (or slab) 2688ft2 – Like 1344, but over a conditioned basement 2200ft2 – 1.5 story split level with garage and bonus room (over crawl)

Multifamily consists of both apartment buildings (≤ 3 stories) and townhouses Apt building is 24 unit double-loaded corridor with 1000 ft2 conditioned

area per unit Townhouse is 12 unit row with 1500 ft2 conditioned area per unit

SF Prototype

Weight

1344 0.15

2200 0.75

2688 0.1

MF Prototype

Weight

1000 apt 0.63

1500 twn 0.37

8

System weightings taken from 2007 baseline study. For multi-family buildings, the apartments are

assigned zonal heating systems. The townhouses use the forced air systems.

System Type Single Family

Multi-family

Gas Furnace 0.26 0.12Gas Furnace with Cooling 0.56 0.2

Heat Pump 0.09 0.05Electric Resistance Zonal 0.09 0.63

9

The existing Oregon Code specifies prescriptive requirements plus the selection of one of nine additional measures. The most common measure used to date is the HVAC system

upgrade to 90 AFUE furnace or 8.5 HSPF heat pump. Therefore, the base case will be modeled with the HVAC system

upgrade. This then sets the baseline energy performance values. The new

code is set to achieve 10% reduction over this baseline energy use.

Existing code does not specify infiltration levels or mechanical ventilation. The base case will use a weighted average of infiltration from the

2007 baseline study Baseline energy use for existing spot mechanical ventilation (bath

& kitchen fans) to be set per discussion with OR-BCD10

Code proposals developed in joint process with multiple stakeholders including OR home builders, NEEA, and others.

Prescriptive requirements in new code will be the same as the old.

The new code savings come from a revised set of additional measure tables. The code will require the selection of two measures. The measures are divided into two categories with one measure being selected from each category. The current proposed measures follow on the next two slides.

11

12

13

Heating and Cooling with SEEM Ventilation with SEEM and side calculations

Building tightness measure requires mechanical ventilation Lighting based on LPD and 1.5 hr/day on time DHW use based on average SF and MF occupancy of 2.9

and 2.74 people per unit respectively Energy of hot water used is ~1150 kWh/yr/person (~22 gal/day)

MELs include all major appliances and plug loads. MELs will be set to a fixed value per housing unit of 4,000 kWh/yr

When complete, the energy use calcs will be combined per the previously discussed weighting scheme to produce a savings estimate. To be presented at next RTF meeting.

14

Not all additional measures will save identical amounts of energy especially when applied to varying climates and house types.

Measure costs also vary giving an indication of which are likely to be selected.

Consideration in final analysis is likely to be given to measure cost which would impact savings estimate. For example, the solar water heating measure might not produce enough savings but it is more expensive than most and therefore not likely to be used with significant frequency. These measure weightings, if appropriate, will be made

clear in the next presentation.

15

The current code proposal also includes provisions for improving the efficiency of remodels / additions in two ways. Prescriptive measure improvements for the building components

altered or added Retrofitting for building components not directly part of addition

(ex: spraying insulation into entire attic - not only the new portion)

These savings will only be evaluated if new construction savings found to be below 10% improvement Approach will require a new methodology. The rough outline is:

▪ Obtain historical permit data for additions and remodels▪ Create new addition prototypes for simulations▪ Determine what fraction of existing buildings would benefit from retrofit style

measures

Full methodology will be presented next time if used

16