ENERGY STAR Laboratory Grade R/F Webinar

transcript

ENERGY STARLaboratory Grade R/F

Webinar

October 23, 2013

Bryan Berringer, U.S. Department of EnergyChristopher Kent, U.S. Environmental Protection Agency

ENERGY STAR Program

Webinar Details • Webinar slides and related materials will be available on the

Laboratory Grade R/F Web page:– www.energystar.gov/newspecs – Follow link to “Version 1.0 is in Development” under “Laboratory Grade

Refrigerators and Freezers”

• Audio provided via teleconference:

– Phone lines will remain open during discussion – Please mute line unless speaking– Press *6 to mute and *6 to un-mute your line

Call in: +1 (877) 423-6338 (U.S.) +1 (571) 281-2578 (International)Code: 356609#

Introductions

• Christopher KentU.S. Environmental Protection Agency

• Bryan BerringerU.S. Department of Energy

• Erica PorrasICF International

• Kurt KlinkeNavigant Consulting

Written Comments

In addition to making verbal comments during today’s call, stakeholders are encouraged to submit written comments to labgraderefrigeration@energystar.gov.

Comment Deadline

Wednesday, October 23, 2013

Webinar Objectives

• Provide overview of DOE validation testing• Present relevant test data, analysis, and

conclusions• Review additional changes from Draft 1 to Draft 2

Test Method

2 Additional Draft 2 Test Method Updates

1 DOE Validation Testing

Agenda

3 Next Steps

Draft 1 Test Method Overview

• Draft 1 Test Method was published Sept. 28, 2012, with comments due Oct. 31, 2012

• Webinar held Nov. 8, 2012

• DOE received significant comments regarding three major issues:– Steady State tolerance– Door opening requirements– Bare vs. weighted thermocouples (TC)

DOE Validation Testing

• Based on comments, DOE decided to perform validation testing

• Several tests performed to evaluate each major issue commented on by stakeholders– Steady State tolerance– Door opening requirements– Bare vs. weighted TCs

DOE Validation Testing• Testing performed at a manufacturer lab • Testing performed on four units

• Units set up per Draft 1 Test Method requirements except– Both bare and weighted TCs used– Weighted TCs placed in 10 mL vial with 50/50 mix of

glycol/water

Unit # Unit Type Configuration1 Lab Grade Freezer Upright

2 Lab Grade Refrigerator Upright

3 Ultra-Low-Temp Freezer Chest

4 Ultra-Low-Temp Freezer Upright

Steady State Tolerance Testing

• Draft 1 Test Method stated that units must reach Steady State prior to testing

• “Steady State: The condition where the average temperature of all TCs changes less than 0.2 °C (0.4 °F) from one 24-hour period or refrigeration cycle to the next.”

• Stakeholders commented that 0.2 °C was too stringent and suggested several other tolerance levels

Steady State tolerance test:• Units set to Draft 1 Test Method set point

temperature• Units run continuously for at least 48 hours• No door openings• Temperature and power measurements taken

every minute– Average Cabinet Temperature and power draw

calculated for each 24-hour period of measurement

Steady State tolerance data:• Temperature – all values in °C

• Not all units could maintain temperature within ± 0.2 °C regardless of TC type

Unit # Max 24-hour Average

Min 24-hour Average

Variation

TC Type Bare Weighted Bare Weighted Bare Weighted

1 -29.81 -29.87 -30.13 -30.15 0.32 0.28

2 4.16 4.36 4.12 4.33 0.04 0.03

3 -80.61 -80.05 -80.72 -80.18 0.11 0.13

4 -79.73 -79.92 -79.94 -80.12 0.21 0.20

Steady State tolerance data:• DOE also evaluated variation in average power draw

for all 24-hour periods

• Maximum variance in average power draw was < 3%

Unit # Overall Avg Power Draw (kW)

Standard Deviation (kW) COV*

1 0.678 0.019 2.7%

2 0.096 0.002 1.6%

3 0.706 0.004 0.6%

4 0.555 0.013 2.4%*COV – Coefficient of Variation – The ratio of the Standard Deviation to the Average

• Testing showed:– Not all units could remain within ± 0.2 °C– Small variations in average temperature did not result in

significant changes in power draw

• Based on testing, DOE has proposed to increase Steady State tolerance to ± 0.5 °C– Reduces test burden by making Steady State easier to

achieve– Does not significantly affect overall variation in energy

consumption of unit

Door Opening Requirements Testing

• In Draft 1, DOE requested stakeholder feedback regarding the door opening (DO) requirements

• DOE received widely varying comments, including:– DOs should not be included and a higher ambient temp

should be used to simulate door openings for ULFs– DO methods not representative of normal operation for

all unit types– DOs may negatively affect repeatability– Agreement with including DOs

• Based on comments, DOE performed testing to evaluate DO

• DOE performed three different tests:– Two using different DO patterns on each unit– One with no DOs in higher ambient temp (32 °C)

• High ambient test only performed on ULF units – Comments specifically suggested this test for ULFs

• Doors opened 1x per hour for 8 hours– Tests performed over two days– Individual door openings and closings performed over

a constant rate of 2 secondsUnits w/ Inner Doors Units w/ Drawers

Day 1 • Open outer door and top inner door• Wait 7 seconds• Close both doors• Use same inner door for each door

opening

• Open main door• Wait 7 seconds• Close main door• Drawers left in “closed” position

Day 2 • Open outer door and top inner door• Wait 7 seconds• Close both doors• Alternate inner door used for each

door opening

• Open main door and top drawer• Wait 7 seconds• Close drawer and main door• Alternate drawer used for each

opening

• DOE tested units 3 and 4 in a higher ambient temp (32 °C vs. 25 °C)– Higher ambient temp meant to simulate increased

load created by door openings– Length of door openings difficult to make repeatable

• Units allowed to reach Steady State• Power measured over course of 8 hours• No door openings

• To evaluate each DO pattern DOE calculated– The average power consumption for each one hour period

and the entire eight hour period– The standard deviation of all eight single-hour periods during

which a door was opened– The Coefficient of Variation (COV, the ratio of standard

deviation to the average power) for all eight single-hour periods

• DOE also compared the overall averages to the average power measured at higher ambient for the two ULFs

Unit 1 Unit 2 Unit 3 Unit 4Day 1 Day 2 Day 1 Day 2 Day 1 Day 2 Day 1 Day 2

Average (kW) 0.767 0.826 0.096 0.095 0.715 0.731 0.647 0.641Std. Dev. (kW) 0.037 0.041 0.003 0.005 0.018 0.014 0.015 0.016COV 4.80% 4.91% 3.63% 6.07% 2.59% 1.97% 2.30% 2.49%

Comparison of Door Opening Patterns

Comparison of Normal vs. High Ambient TempUnit # Average Power Consumption (kW)

Day 1 DO Day 2 DO High Amb.

3 0.715 0.731 0.917

4 0.647 0.641 0.590

• Testing showed that both DO patterns provided relatively consistent results for each 1-hour period– The Day 1 pattern was more consistent than Day 2

• COV < 5% across all units

• High Ambient Temp testing showed no correlation with the DO tests

• Based on this testing, DOE– Does not believe testing at a higher ambient temp to

be a valid method of simulating DOs– Believes that door openings can be performed and

provide consistent results

• As such, DOE has proposed to continue including door opening requirements using the Day 1 pattern

Bare vs. Weighted TCs

• In the Draft 1 Test Method, DOE specified using bare, unweighted TCs– DOE requested feedback regarding the use of bare vs. weighted

• Stakeholders commented that staying within specified Set-Point Temperature tolerances would be difficult with bare TCs

• Based on these comments, DOE performed all testing with both bare and weighted TCs – Weighted TCs placed in 10 mL vials filled with a 50/50 glycol/water

mixture

• DOE compared the average Cabinet Temperature over the course of each test– Both 8-hour DO tests– 48-hour Steady State test

• Testing showed minimal variation between TCs– Average of 0.29 °C difference

• As such, DOE has proposed to continue using bare TCs for all testing– Both types of TCs provide similar values– Reduces test setup burden compared to using weighted TCs

Unit 1 Weighted Bare DifferenceDO Day 1 -30.221 -30.197 0.024

DO Day 2 -30.391 -29.983 0.409

Steady State -29.872 -29.961 0.089

Unit 2 Weighted Bare DifferenceDO Day 1 4.214 4.044 0.170

DO Day 2 4.351 4.156 0.195

Steady State 4.344 4.136 0.208

• Data comparison between TC types for average Cabinet Temperature over course of each test– All values in °C

DO Day 2 -79.945 -80.494 0.549

Steady State -80.121 -80.675 0.554

DO Day 2 -77.922 -77.604 0.318

Steady State -80.027 -79.833 0.194

Additional Comments

Additional Comments?

Written Comments are due by October 23

Agenda

3 Next Steps

Additional Draft 2 Updates

• DOE made additional updates to the Draft 2 Test Method regarding the following topics– Ambient Test Conditions– Volume Measurement Requirements– Defrost Adequacy Test– Reporting Requirements

Ambient Test Conditions

• In the Draft 1 Test Method, DOE included lighting and radiant heat ambient condition requirements– Draft 1 Requirements based on ASHRAE 72

• Stakeholders commented that these requirements were unnecessary and increased burden– Lighting and radiant heat have no noticeable effect on

unit energy consumption

Ambient Test Conditions

• After further evaluation, DOE does not believe these requirements are applicable to Lab Grade R/F

• As such, DOE has proposed to remove the lighting and radiant heat requirements– Requirements do not affect Lab Grade R/F– Reduces test burden by easing the preliminary test

setup requirements for labs

Volume Measurement Requirements

• After publication of Draft 1, DOE reevaluated the volume measurement requirements– Requirements were not based on known industry

standards

• Based on its evaluation, DOE has proposed to update the volume measurement requirements to reference ANSI/AHAM HRF-1-2008– Common industry standard used for R/F– Provides standardized method of determining volume

Volume Measurement Requirements

• Stakeholders also requested that CAD drawings be allowed when determining net useable volume

• DOE agrees that CAD drawings be allowed– If used, all measurements and calculations must meet

HRF-1-2008’s requirements

• As such, DOE has proposed to update the requirements to allow the use of CAD drawings

Defrost Adequacy Assurance Test

• The Draft 1 Test Method included a test to evaluate the adequacy of any automatic defrost

• DOE received multiple stakeholder comments agreeing that the test:– Is extremely subjective– Significantly increases total test time

• After evaluation, DOE agrees with the stakeholder comments and has proposed to remove the test– DOE requests feedback regarding alternative methods

Reporting Requirements

• DOE received stakeholder comments requesting the reporting of additional values– Uniformity– Stability– Peak Variance

• DOE agreed with stakeholder comments and has proposed requiring the reporting of the listed values– Values are calculated for a 3-hour period, not including

any part of the 8-hour DO period

Reporting Requirements

• Uniformity: The difference between the maximum and minimum temperature measured inside of a unit’s cabinet at any given time

• Stability: The difference between the maximum and minimum temperature measured by a given thermocouple over the course of the entire test period

• Peak Variance: The difference between the maximum and minimum temperatures measured across all thermocouples over the course of a given measurement period

Additional Comments

Additional Comments?

Written Comments are due by October 23

Agenda

3 Next Steps

Test Method Development Timeline

Draft 2 Version 1.0 Test Method to stakeholders September 2012

Draft 2 Version 1.0 Test Method comments due October 2012

Draft 3 Version 1.0 Test Method to stakeholders (if needed) December 2013

Draft 3 Version 1.0 Test Method comments due January 2014

Final Draft Version 1.0 Test Method to stakeholders Spring 2014

Final Draft Version 1.0 Test Method comments due Spring 2014

Final Version 1.0 Test Method Summer 2014

Written Comments

In addition to making verbal comments during today’s call, stakeholders are encouraged to submit written comments to labgraderefrigeration@energystar.gov.

Comment Deadline

Wednesday, October 23, 2013

Contact Information

Please send any additional comments to labgraderefrigeration@energystar.gov or contact:

Thank you for participating!

Bryan BerringerDOE ENERGY STAR ProgramBryan.Berringer@ee.doe.gov

Kurt KlinkeNavigant Consulting, Inc.Kurt.Klinke@navigant.com

Christopher KentEPA ENERGY STAR ProgramKent.Christopher@epa.gov

Erica PorrasICF InternationalErica.Porras@icfi.com

www.energystar.gov/productdevelopment

ENERGY STAR Laboratory Grade R/F Webinar

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