PNW RoofTop Unit Working Group - RTUG –

RTU Savings Research ProjectPhase 3

December 15, 2009

RTUG Agenda 12/15/09• 9:30-9:45am - Presentation on expected RTU savings and potential from

the NW Power and Conservation Council’s 6th Power Plan- NW Energy efficiency Alliance Service Assistant Project Update

• 9:45-10:45 Results: Bonneville RTU Savings Research

>> 10:45-11:00 Break

• 11:00-12:00pm Discussion: Bonneville Results

• 12:00-12:15pm Results: Idaho Power RTU Savings Research

>> 12:15-1:15pm Lunch Break - WEB shows agenda; telcomm off line

• 1:15-1:30pm Results: Energy Trust of Oregon RTU Pilot Savings

• 1:30-1:45pm Results: Puget Sound Energy RTU Savings Evaluation

• 1:45-2:00pm Results: AirCare Plus℠ in California

• 2:00-3:30pm Discussion: Next Steps- Use of the data for additional analysesOptions for Assessing Expected Value SavingsRecommendations to the RTF - January 5, 2010

PNW Regional Summary 226 RTUs Serviced/Measured!

• Avista = 6 pairs to be metered

• Bonneville Power Administration RTU Pilot = 150 metered + 11 from Avista - 2008

• Energy Trust of Oregon = 15 metered/94 total

• Idaho Power = 9 metered

• Puget Sound Energy = 41 metered

Idaho Power RTU

• 3 sites, 3 units per site, 12 months all units (Sept. 09 – Sept. 10)

• Level 1 monitoring 2 per siteLevel 2 monitoring 1 per site

• Heating signal at 1 unit per site• Heavy equipment supply/repair; title

insurance company; wholesale beverage

Idaho Power RTU Summary Results

Summary weather compressor Savings Pre Post Pre

site ID RTU ID size tons data Stages kWh/yr kWh/yr kWh/yr

t'stat stages Econo?

Bigelow #1 5 BOISE 1 -2,145 8,193 10,339 Yes Bigelow #2 7 BOISE 2 0 6,236 6,236 Yes Bigelow #3 10 BOISE 2 6,479 38,710 32,231 Yes Cesco #1 7 BOISE 1 86 14,351 14,265 yes Cesco #2 7 BOISE 1 0 12,072 12,072 no Cesco #3 6 BOISE 1 -7,905 7,827 15,733 yes Nampa #1 5.5 BOISE 1 -180 7,162 7,342 yes Nampa #2 7 BOISE 1 -7,227 2,853 10,080 yes Nampa #3 5.5 BOISE 1 6,161 10,652 4,490 yes

Interpretation of Results - Idaho

• 2 units fan power increase due to filter cleaning

• 1 unit incomplete economizer damper opening

• 2 units fan schedule increase to 24 hours, major losses

• 1 unit fan schedule reduction, major savings

• 1 unit properly operating in pre-retrofit

• 2 units failure to set back schedule

Take Away Results - Idaho

• Net savings all RTUs: - 4,700 kWh/yr• Savings target for refined settings: 23,000 kWh

dependent on schedule settings

Favorable Schedule Change - Idaho

Time Series

0

2

4

6

8

10

12

2016

6

2064

6

2112

621

606

2208

6

2256

6

2304

6

2352

6

2400

6

2448

6

2496

6

2544

6

2592

6

2640

6

2688

6

2736

6

2784

6

2832

6

2880

6

2928

6

2976

6

3024

6

3072

6

3120

6

3168

6

3216

6

3264

6

3312

6

3360

6

3408

6

3456

6

3504

6

3552

6

3600

6

3648

6

3696

6

3744

6

3792

6

3840

6

3888

6

3936

6

3984

6

4032

6

4080

6

4128

6

Hour of Day

Pow

er k

W kW #3OSA/10max

A Puzzle - IdahoEnergy Signature

0

20

40

60

80

100

120

140

160

180

200

220

40 45 50 55 60 65 70 75 80 85 90 95 100

Mean Month Temperature

Ener

gy, k

Wh/

day

mod postmod predata predata post

This unit had a significant economizer improvement.

Why did slope increase?

Maximum Power Signatures - Idaho

• Fan power decreased from ~1.5 kW to 1.4 kW due to filter replacement because flow increased

• Post-retrofit power increased for both stages due to flow increase, more cooling delivered

• Increased cooling doesn’t reduce cooling energy because thermostat setting not achieved

Compressor Usage

0

2

4

6

8

10

12

14

40.0 45.0 50.0 55.0 60.0 65.0 70.0 75.0 80.0 85.0 90.0 95.0 100.0

Average Hourly Temperature, deg F

Com

pres

sor k

Wh

or M

ax k

W

pre comppost comppre maxpost max

Next Steps - Idaho

• Properly set schedules• Monitor winter operation –consider morning

warm up• Next summer establish improved post-retrofit

performance and savings

California RTU Monitoring

• About 300 RTU new replacements instrumented for post-retrofit air-side output and electrical input

• No pre-retrofit measurement – “empirical pre-retrofit baseline drawn from selected samples”

• Monitored for 1-2 summer months

• Differ from NW monitoring by inclusion of return RH and Supply Air Temp with hourly data structure not average daily structure

• Results are normalized to performance efficiency

• Reconciliation with DEER modeling

California Results Example 1Analytic Target: Monitored performance as EER vs. Temperature

EER Performance Model

0.002.004.006.008.00

10.0012.0014.0016.0018.0020.00

70.00 80.00 90.00 100.00 110.00

Hourly Temperature, deg F

EER

model

hi

mxt

lo

California Results Example 2Monitored performance Compared to DEER

EER Performance

0.00

2.00

4.006.00

8.00

10.00

12.00

14.0016.00

18.00

20.00

70.00 80.00 90.00

Hourly Temperature, Deg F

EER

observed SEER 10 ref SEER 13 ref

Summary Results - CA

• Results to be published 12/21/09• Observed performance generally lower than

modeled expectation

Regional Results Database• Results from all programs will be entered• Primary structure a directory tree with each

program results as a separate directory• Each directory: unit raw data/template +

results summary for each units + site/unit characteristics & service measures

• Uniform format not being designed• Summary data will include selected site/unit

characteristics

Database Summary View

Site Summary• Site ID• RTU ID• Weather data• Annual kWh pre• Annual kWh post• Compressor stages• Compressor max duty (frac of

full load)• Economizer (y/n)• Monitoring level

Pre- and Post- Service Summary• Fan kW• Fan duty (frac of full load)• Baseload kWh/day• Balance point temp• Slope kWh/day/degF• Demand @ 80 deg F, Stage

1&2 kW• Compressor trigger degF

Database Format Refinements

• The format will change to accommodate the economizer analysis made possible by the Y1 signal most recently being monitored

• The format will change to accommodate more detailed descriptions of measures applied

• The summary row proceeds from the current template. Other analysis approaches and revised templates may have different summary row formats

Use of Regional RTU Data

• Data to be available through NPCC site• Getting 8760 results/analysis/EER vs Temp• EUI per conditioned sf• Sensitivity analysis on methodology• IPMVP Method B analysis: 2 week data only• Correlating data to building characteristics -

partial data available• Annual savings methodology using signatures

RTUG Next Steps

• Prepare presentation to RTF• Discuss with NPCC staff, RTU database implementation

+ integration with other regional buildings-related database(s)

• Further development of ‘Expected Value Savings’ [aka Deemed Savings]

• Continue communications with California organizations