Rooftop Unit Working Group- RTUG -

January 19, 2010

Up on the Roof…”Up on the roof I've found a paradise that's trouble proof, up on the roof.”

—C. King/G. Goffin 1962

RTUG Agenda 9:30am Objectives/Process for the Meeting

9:45-11:00 Program and Field Lessons Learned/ Recommendations

11:00-11:15 Break

11:15-12:15pm Strawman Discussion Part 1: Protocol/Savings/ Costs/EM&V

12:15-1pm Lunch

1:00-2:30pm Strawman Discussion Part 2: Protocol/Savings/ Costs/EM&V

2:30-3:00pm Decision Summary

3:00-3:30pm Proposed RTUG-NBI Scope of Work

RTUG Jan 19, 2010

Regional Technical Forum Savings Categories

DeemedDeemed Calculated

Not DeemableProvisional

RTUG Jan 19, 2010

Categories of RTF Savings & Cost Estimates

Deemed

Deemed Calculated

Not Deemable

Same as Deemed, but with case- or program- specific calculations to adjust for specific conditions that strongly influence savings such as hours of operation, climate zone, vintage.

Insufficient information to produce deemed savings or deemed calculation. Applies to unique facilities, and situations. Use RTF “Group” or “Site Specific” evaluation and verification protocols to establish savings.

RTUG Jan 19, 2010

Provisional Deemed Estimates

Provisional DeemedInterim estimates where there is not sufficient program evaluation data to deem savings.

But there is some confidence in costs & savings based on limited evaluation, AND

Program operation is designed to provide data that would allow deemed or deemed calculated estimates or lead to an approved M&V protocol.

Provisional Deemed Savings Estimate

Program M&V Plan

“Book” Provisional Deemed Savings

Evaluate Actual Savings per M&V Plan

True-Up Savings

Streamlined M&V Protocol

RTUG Jan 19, 2010

What it Takes to Deem• Annual energy savings can be reliably predicted

– Known variance based on prior program evaluations or generally accepted engineering calculations

• Diurnal & seasonal energy savings reliably predicted

• Current baseline practice is consistent with practice on which prior savings estimates were established

• Measure specifications are consistent with measures evaluated to establish savings or assumptions used in engineering calculations

• Measure is at least as efficient as the measure used to establish savings based on prior program evaluations

RTUG Jan 19, 2010

Additional Considerations

• Overall Savings Potential Matters– The level of effort to determine savings should

match the savings potential

• Deemed Savings Don’t Last Forever– Technology, markets, and programs change –

deemed savings should change with them

RTUG Jan 19, 2010

Savings in MWa 2029 – 6th Power Plan

NewNew NRNR RetroRetro TotalTotal

Package Roof Top Package Roof Top Optimization and RepairOptimization and Repair

44 88 1414 2626

Demand Control Demand Control VentilationVentilation

44 33 1818 2525

TotalTotal 88 1111 3232 5151

TRC Levelized Cost: Mostly $10 to $50 per MWh

RTUG Jan 19, 2010

PNW RTU 2008-09 Count 236 Metered

• Avista = 12 side-by-side metered [2 pair in place]

• Bonneville Power Administration RTU Pilot = 161 metered [45 @ 12 months]

• Energy Trust of Oregon = 94 serviced/13 metered

• Idaho Power = 9 metered [all @ 12 months]

• Puget Sound Energy = 41 metered

RTUG Jan 19, 2010

It takes a village……

RTUG Jan 19, 2010

2009 RTU Savings Results –What We Know

2009 RTU Savings Results What We Know - 2 Bonneville ETO Idaho Power PSE

RTUG Jan 19, 2010

2009 RTU Savings Results –What We Still Need To Know

Initial Analysis kWh/Ton – PECI

RTUG Jan 19, 2010

Initial Analysis kWh/Ton – PECI

RTUG Jan 19, 2010

Tons y = 312x - 784.97 y = 234.02x Mira's Proposal tons Frequency

2 (161) 468 0 500 0 2 0

3 151 702 3510 500 2500 3 5

5 775 1,170 45630 500 19500 5 39

7.5 1,555 1,755 45630 2500 65000 7.5 26

10 2,335 2,340 35100 2500 37500 10 15

15 3,895 3,510 42120 2500 30000 15 12

20 5,455 4,680 23400 2500 12500 20 5

Ton based savings 195390

Large/Small based

savings 1670000.8547008

55 More 0

200kWh per ton

ETO Summary of Electric Savings

CasePre- retrofit

kWhPost- retrofit

kWhKWh

Saved % Saved Treatment

Dentist Back 5,826 1,645 4,181 72% New economizer, new thermostat, implemented setback

Dentist Front 7,827 2,716 5,112 65% New economizer, new thermostat, implemented setback

Pizza Kitchen 3,192 1,159 2,033 64% New economizer, new thermostat, implemented setback

Sandwich Shop 15,131 6,432 8,699 57% New economizer, new thermostat, implemented setback

Shipping Store 2,949 1,255 1,694 57% New economizer, new thermostat, implemented setback

Pub 5,716 3,381 2,334 41%Restored non-functioning economizer, set changeover to 63 deg, new thermostat, implemented setback

Office 4,658 3,759 899 19%New economizer, existing thermostat, implemented setback

Pizza Front 12,941 10,632 2,309 18% No economizer, new thermostat, implemented setback

Vet Front 3,561 3,150 411 12%Restored non-functioning economizer, set changeover to 63 deg, new thermostat, implemented setback

Hair Salon 4,026 3,922 104 3%New economizer, new thermostat, implemented setback, increased ventilation

Retail Front 2,421 2,371 49 2%Existing economizer was functional, set changeover to 63 deg, new thermostat, implemented setback

Vet Back 4,231 4,169 62 1% New economizer, new thermostat but no setback

Retail Back 316 323 -7 -2% Cleaning but no other treatment, unit is seldom in use

Average5,600 3,455 2,145 38%

All units (15 cases) 2,074 37%

Idaho Power RTU Results

RTUG Jan 19, 2010

Overview of Air Care + Energy Savings:Overview of average energy savings per measure per unit: *

* kWh savings based on results in prior California IOU Air Care Plus programs by PECI. * Average unit size: 7.62 tons (except refrigeration: 4.7 tons single compressor; 12.6 tons multiple compressor).* Energy savings per measure are deemed and supported by approved workpapers, and Avoided Cost Calculator Workbook (E3) calculations.* Actual energy savings will vary with each customer’s situation, including but not limited to the actual measures or equipment installed, building construction, customer operation, age of existing equipment, and location.

By Measure:Measures rebated kWh total

kW total

Therms total

Average kWh/unit

Average kWh/ton

Average Therms

Basic Package Without Economizer 5,026 490,538 0 0 98 12.8 0.0

Basic Package With Economizer 3,424 7,455,994 0 0 2,178 285.8 0.0

Economizer Refurbish 699 1,578,479 0 0 2,258 296.4 0.0

Economizer Control Package 188 265,035 0 0 1,410 185.0 0.0

Refrigerant Pre-Test 7,499 0 0 0 0 0.0 0.0

Refrigerant/Airflow (1 Comp.) 3,446 4,017,692 1,344 0 1,166 248.1 0.0

Refrigerant/Airflow (2 Comp.) 1,739 3,418,919 1,207 0 1,966 156.0 0.0

Thermostat Modification 1,685 1,551,392 0 18,492 921 120.8 11.0

Thermostat Replacement 206 1,075,717 0 14,037 5,222 685.3 68.1

Totals by Measure: 23,912 19,853,767 2,551 32,529      

RTUG Jan 19, 2010

Detailed Findings

RTUG Jan 19, 2010

BPA Pilot Evaluation Elements

Pilot evaluation approach:

– Measure cooling and fan energy use at individual RTU level

– Larger sample size

– Two week pre/post metering with annualization

– Energy signature (kWh and OA temperature) and TMY3 weather data to annualize cooling and fan energy savings

– Compare metered savings to estimated savings

Report results and lessons learned to improve estimation, measurement, and realization of energy savings

Recommend improvements to direct BPA’s 2010 Performance Tested HVAC program

RTUG Jan 19, 2010

Performance Tested HVAC Thermostat measures

– Replacement

– Setpoint and schedule changes

Economizer measures

– Economizer commissioning

Setpoint changes

Fixing dampers

Replacing or repairing broken parts

– Minimum and maximum ventilation adjustment

Refrigeration cycle measures

– Condenser and evaporator coil cleaning

– System airflow adjustment

– refrigerant charge adjustment

RTUG Jan 19, 2010

Premium Service PackagesPremium Service Packages

• Each RTU received a package of measures

• Basic Diagnostic package (A):

Other packages:– B (basic diagnostics plus fix damper)– C (basic diagnostics plus new thermostat)– D (basic diagnostics plus new controller)

RTUG Jan 19, 2010

BPA On-Site Data CollectionBPA On-Site Data Collection

• 161 RTUs metered

• Minimum two weeks baseline and post-servicing

• One-minute data

• Site characteristics recorded

• On-site data collection HOBO U30 loggers/CDA– Basic metering package:

Total unit power Outside air temperature/RH

– Modified basic package: Supply air temperature Y-1 call for cooling

– Full package: Return air temperature Supply air temperature Mixed air temperature

RTUG Jan 19, 2010

BPA Sample Distribution

24RTUG Jan 19, 2010

BPABPA Metered SavingsMetered Savings Average savings by unit age

Average savings by RTU type

Average savings by existing servicing contract

RTUG Jan 19, 2010

Savings Algorithm

Energy signature: used with TMY3 data to annualize energy– Horizontal line = fan energy– Sloped line = fan + compressor energy– Balance point = intersection of horizontal and sloped lines

26RTUG Jan 19, 2010

Metered Metered Savings 161 RTUs metered

102 RTUs in Puget Sound, Tri-Cities and Spokane areas with complete post-servicing data

Mean cooling and fan energy savings:

1,615 per RTU and 172 kWh/ton

RTUG Jan 19, 2010

BPA Metered Savings

• Total cooling and fan energy savings

RTUG Jan 19, 2010

RTUG Jan 19, 2010

53 units with ± 10% savings; avg 199 kWh

RTUG Jan 19, 2010

RTUG Jan 19, 2010

BPA Metered Savings

Compressor and fan savings (kWh/ton)

32RTUG Jan 19, 2010

BPA Thermostat Measure Savings Operating schedules

– Average savings for 30 RTUs: 3,307 kWh

– Average savings 7 tons and greater: 5,198 kWh

– 83% of the units realized savings

– Maximum savings: 15,408 kWh

RTUG Jan 19, 2010

Straw RTU RetroCx Program Elements

• Preliminary screening for program eligibility

• Contact customer and get permission for service

• Determine serving utility

• Fill out and submit program application

• Train technician, purchase, maintain and calibrate tools

• Submit all required documentation

RTUG Jan 19, 2010

Straw RTU RetroCx Program Eligibility Elements • Constant volume rooftop unit (RTU) with economizer • Constant volume rooftop unit (RTU) without economizer• Constant volume rooftop unit (RTU) with economizer less

than 5 years old • Constant volume rooftop unit (RTU) with economizer over 20

years old (essentially obsolete) • Split systems • Variable Volume Temperature • RTUs 3 tons and under • RTUs over 20 tons • RTUs over 60 tons • RTUs controlled by EMS • Ongoing PM service contract

RTUG Jan 19, 2010

Straw RTU Package ServicesPkg A1: Replace sensor

A2: Add OSA relay for morning warm-up Pkg B: Fix Damper Pkg

B1: Fix Damper + Replace sensor B2: Fix Damper + Add OSA relay for morning warm-up

Pkg C: New Tstat Pkg C1: New Tstat + Replace sensor PkgC2: New Tstat + Add OSA relay for morning warm-up

Pkg D: New Economizer Controller (replace snap disk, C7650 or broken controllers) D1: New Economizer Controller + Replace sensor D2: New Economizer Controller + Add OSA relay for morning warm-up

Pkg E: DCV Pkg F: New Economizer Controller + New TstatPkg F: New Economizer Controller + New Tstat

F1: New Economizer Controller + New Tstat + Replace sensor Pkg G: New Economizer RTUG Jan 19, 2010

Straw Basic Diagnostics 1 RTU operational check -does everything work? 2a Document existing conditions (25 fields) 2b Document existing conditions (50 fields) 3 Clean coils 4 Test and document existing economizer and operation5 Document existing economizer equipment6 Test and document existing economizer operation 7 Check thermostat: stages, setpoints and schedules and adjustment 8 Minimum outside airflow measurement and adjustment 9 Maximum outside airflow measurement and adjustment 10 System airflow measurement and adjustment 11 Refrigerant system check 12 Refrigerant system adjustment 15a Document final conditions (50 fields) 15b Document final conditions (100 fields)

RTUG Jan 19, 2010

Straw RTU RetroCx Program Elements

• Trade Ally Network • Training and outreach • Subsidize cost of tools • Require technician certification -if yes specify type • Quality control • Refresher training • Performance specification • Follow-up with owner

RTUG Jan 19, 2010

Straw RTU RetroCx EM&V• Sampling plan for site specific M&V to provide additional data to

support deeming

• Provide pre- and post- metering on 10% of RTUs, up to 50 Annual M&V

• Provide analysis to:

1) Verify M&V methodology

2) Calculate error bounds for local temp vs TMY3 data

3) Observe schedule persistence, heating performance and NLL fan operation

4) Report results winter of 2011 to RTUG.

5) Oct 1, 2011 recommended sunset date for provisionally deemed savings (22 months)

RTUG Jan 19, 2010

PTHVAC Protocol Package Costs

– $360 A (basic diagnostics)– $360 B (+ fix damper)– $660 C (+ new thermostat)– $560 D (+ new controller)– $760 E (+ DCV)– $810 F (+ new controller/thermostat

RTUG Jan 19, 2010

ETO Program Cost Effectiveness

Cases Average KWh Average Thermstudied Savings Savings13 Directly monitored 2,145 38% 2.4 0.6%15 Including all units 2,074 37% 2.5 0.6%Unit cost $1,685

PV of electricity, per kWh $0.980 $0.702PV of Gas, per therm $7.872 $6.078PV of Benefits $2,052 $1,471BCR 1.22 0.87Discount Rate 5.2% 5.2%Lifetime 15 10Levelized Cost, per kWh $0.078 $0.105

RTUG Jan 19, 2010

Idaho Power Easy Upgrades

• Economizer controls $75

• Economizer system repair $250

• Two-stage T-stat $40

• Variable speed drive, fan $60

• Pre-cooler added to condenser $100/ton

PNW RTU Results Database Summary

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

RTUG Jan 19, 2010

2009 PNW RTU Outcomes

• Critical Body of Knowledge being assembled

• Measurement & analysis continuing >12 months

• Results database being established for additional analysis

• Provisional deemed savings potential

RTUG Jan 19, 2010

RTU Efficiency Measures that are NOT Measured by EER, SEER & IEER

• Economizer and damper effectiveness

• Damper seals

• Demand Controlled Ventilation (DCV)

• Variable speed fan; low speed during idle

• Ventilation lockout during warmup

RTUG Jan 19, 2010

Premium Ventilation Package

• Start with a Western Premium Economizer

• Upgrade the Economizer module with

– DCV capable economizer control module

– CO2 Sensor; Min air set to 0% = leakage

• Add variable speed fan motor

– Full (or near full) speed in heating or cooling

– Low (30%) speed in idle mode

• Field testing currently underway

RTUG Jan 19, 2010

Economizer Control “Hysteresis” Problem

• A study organized by Northwest Power and Conservation Council Regional Technical Forum

• For the most common economizer controller and sensor– A wide hysteresis [6-10degF] was found in

2008 bench testing; manufacturer concurred– Economizing will not occur unless night time

temperatures fall to the low set point, which may not happen

Earlier tune-up adjustments to existing packaged systems did not achieve expected savings

• Two investigations showed – economizers did not work as

expected – even after proper adjustment

procedures were followed

RTUG Jan 19, 2010

Manufacturer Cooperated in Replacement

Manufacturer has redesigned dry-bulb sensor: Honeywell C7660 replaces C7650

Sensor controls controller [W7459]

Digital functionality

New sensor will minimize the control deadband and improve precision.

Can be retrofit toexisting controllers – same form factor

Approx. $4 incremental cost

RTUG Jan 19, 2010

Outside Air Sensor Placement

RTUG Jan 19, 2010

Rooftop Unit Working Group Time Line

NEEA2002-2004

RTFPhase I

2004

RTFPhase II

2006-2007

RTFPhase III

2009-2010

• Pilot Field Work• Inconclusive savings• Identified potential deadband issues• Not ripe for Market Transformation • Lab Testing

• Limited Field Test• Honeywell Redesign• Develop Protocol to Measure Savings• Scope Next Phase

• Secondary Source Review• Frequency of Problems• Scope Next Phase

• Test Protocol to Measure Savings• Large Field Test• Goal: Prov Deemed, Deemed Calc/MV Protocol• Scope Next Phase

RTUG Jan 19, 2010

2010 RTUG Workplan• Establish recommended directions for regional RTU service

program work in 2010– Report to RTF at February 2 meeting

• Results database up and running- BPA data first; data dictionary development [Cadmus]- Primary/summary datasets with a R&A section- Integrate 12-month Idaho Power results; ETO initial results- Ongoing storage of annual data• Ongoing results analysis including:

– Schedule/fan/temperature/economizer persistence– Winter results– Additional analyses TBD

RTUG Jan 19, 2010

2010 RTUG Workplan -2• Annualized analysis of BPA and Idaho Power units

– Substantiate/revise annualized savings methodology– Reconcile temperature measurements w/site & TMY– True up Provisional Deemed Savings as appropriate– Incorporation of Idaho DCV data

• Align regional modeling to data/results: prove that modeling can produce a signature• Next generation, including, but not limited to: DOAS Add economizers Premium Ventilation & DCV Early replacement• Manage and support RTUG activities

RTUG Jan 19, 2010

Total US Cooling Solution

50 ZILLON TONS @ SEER 726

CTU - Country Top Unit

RTUG Jan 19, 2010