1. Test procedure development Mobile Air Conditioning (MAC) Stakeholder meeting, Brussels, 07-10-2010

2. 2 Contents Project overview Draft of the test procedure Chassis dynamometer tests Influence of glazing quality Test Evaluation Preliminary results Next steps Fonts: blue = Option green = suggestet

3. 3 Project overview Goal: To develop test conditions and procedures for MAC Main evaluation parameter: impact on fuel consumption Procedure should be clearly discriminative of different systems Target accuracy and repeatability need to be clearly established

4. 4 Project overview Test conditions based on typical European: Climatic conditions (temperature, humidity) Operational conditions Consumer habits Three basic operational modes: Cool down To simulate vehicle interior cool-down after heat soak Constant temperature To simulate operation with a constant temperature interior Simulation based or HIL (Hardware in the Loop) E.g. COP map with duty cycle

5. 5 Project overview Definition of a test procedure(s) for MAC performance at type approval Focus on physical testing: Cost efficiency Realistic representation of MAC efficiency Use previous experience (ADAC 2007)

6. 6 Simulation of “Seasonal Performance” of MAC system to determine most important ambient conditions Analysis of Weather Data Simulations by means of “Seasonal Performance” (LCCP) MAC test conditions Results presented in last meetings for Athens, Frankfurt, Helsinki Summary: main share in additional fuel consumption between 20°C and 30°C ambient temperature  25°C at 50% RH defined. 21°C interior temperature defined as representative. 700 W/m² suggested as solar radiation (higher than EU average to consider heat up during parking, which is not part of the test procedure).

7. 7 Factors to be considered in test procedure 1.Test cycle („easy to drive” for repeatable results at small fuel consumption effects) 2.Ambient temperature and humidity 3.Interior temperature to be reached with MAC 4.Mass flow of the MAC system 5.Simulation of heat from sun radiation 6.Evaluation method for test results Option for test procedure: Test vehicle on the chassis dynamometer with and without MAC. Difference is the additional fuel consumption from the MAC system. Define following settings:

8. 8 Chasis dyno tests Test cycle: Options tested = 2-step, 3-step, NEDC Selected: 3-Step cycle (developed by ACEA) MAC test cycle Advantages: Covers 3 speed ranges (different rpm for compressor) Tests MAC-on and MAC-off within same analysers calibration  less uncertainty

9. 9 Chassis dyno test MAC test cycle 1960 - 2220 2320 - 2580 2710 - 2970 3090 - 3350 3450 - 3710 3840 - 4100 Evaluation periods suggested: MAC on MAC off MAC on measurement MAC off measurement 1) Preconditioning as defined in EC 692/2008 for emission tests 2) Soak >8h at 25°C (+/-2°C) at 50% RH (+/-5%RH) 3) start MAC test, until second 1400 the MAC setting shall be found for 21°C cabin temperature (alternative 15°C vent outlet) MAC on, m >230 kg/h Pre conditioning (t i = 21°C) Additional MAC FC = Weighted average [kg/h] MAC on - Weighted average [kg/h] MAC off

10. 10 T C3 T a,  a To CVS, exhaust gas analyser  g CO 2 /km Chassis dynamometer blower Positions of sensors “ambient temperature” 25°C and 50% RH measured at testbed-blower inlet Vehicle temperature measured in the cabin (details see next slide) mama mlml 330 mm to roof 30 mm Chassis dyno tests airstream

11. 11 Option a): weighted average of 3 positions for cabin temperature This avoids special optimisation of vent(s) for one temperature sensor position. Sensors position in the vehicle as shown in the picture: Chassis dyno tests 330 mm to roof 30 mm Option b): highest vent outlet temperature shall be <15°C. Effect of option b): vehicle size has nearly no influence on test results. No effort necessary to optimise flow in vehicle for the sensors positions. Not guaranteed that this setting would reach 21°C in the cabin. What we suggest: option c = a+b gain experience in pilot phase where temperatures are recorded for both options Positions of sensors for cabin temperature

12. 12 4 x „vent outlet temperature Chassis dyno tests Set up of option „vent outlet“

13. 13 Chassis dyno tests Other options to be discussed: Conditioning of the state of charge (SOC) of the battery Background: basically air conditioning could be driven electrically only from battery  no additional fuel consumption if battery not charged during test. Option a): measure energy flow and correct for difference kWh in/out with constant efficiency (e.g. 50% hel at 230 g/kWh). Option b): as a) but with measured efficiency. Option c): start one test with minimum SOC and a second test with maximum SOC. In actual tests SOC differences were small, future technologies may behave different. Suggestion: default = Option a), alternative = Option b) on OEM demand

14. 14 Chassis dyno tests Other options to be discussed: Test of low ambient temperature behaviour Background: According to (Weilenmann et.al., 2010) “two-thirds of CO 2 and fuel consumption from MAC activity could be saved without discomfort by switching off the MAC below 18 °C. Option: First preconditioning before soaking at <18°C with MAC in automatic position. If MAC is not activated with engine start a “bonus” for the MAC fuel consumption could be granted (20% to 50% of the MAC fuel consumption measured later?) Question: any important disadvantages) MAC activation for de- fogging, defrosting etc. shall not be prohibited. Ambient conditions need to be specified to avoid condensation issues

15. 15 Glazing Tests with solar lamps are expensive In-Use tests are not repeatable  laboratory tests of glazing quality according to ISO 13837 & Simulation Good glazing quality can save MAC energy demand  Incentive for good quality shall be given in test procedure Simulation of heat entrance into the vehicle cabin Consider this heat entrance by Option a) with a correction value in the evaluation Option b) during tests by adapting the MAC mass flow or Option c) during tests by adapting the test cell temperature

16. 16 Glazing: simulation of heat entrance Energy balance from radiation and convection E interior = T Ts x E total sun radiation in [kW/m²] for defined solar radiation (700W/m²) E total sun radiation = E absorbed + E transmitted + E reflected 100% =  e + T Ds + R Ds Measured according to ISO 13837 Share of re-emission into cabin from heat transfer coefficients h i and h e Heat entrance to cabin = E transmitted + to cabin re-emitted part of E absorbed Details see presentation from Volkmar Offermann (Saint-Gobain Sekurit)

17. 17 Calculation of heat entrance into the cabin due to sun radiation Options for application of the approach discussed with Saint-Gobain Sekurit and NSG, calculation tool provided by Saint-Gobain Sekurit (V. Offermann and F. Manz) Option a): Application of calculation tool. Complex validation of tool necessary before it becomes standard. Option b): Provide look up table for W/m² as function of glazing (T Ts value and angle of installation). Interpolation from table and multiplication with pane m². We suggest option b. Draft table could be veryfied by all stakeholders. Eventually diverging results may need further discussion.

18. 18 Summary on suggested procedure for glazing 1.Heat entrance from solar radiation [kW] from look up table 2.Additional fuel consumption calculated from other look-up table [kg/h] as function of [kW] 1. 2. k

19. 19 Test evaluation i….single speed steps (0, 50, 100 km/h) Additional MAC fuel consumption in [kg/h] Idling = 15% 50 km/h = 65% 100 km/h = 20% Total result = weighted average according to real world shares: C Pei, C COPi ….Correction factors (details next slide) Basic problem of MAC tests: Small value is gained from difference of 6 large values Accurate measurements and affective correction for deviations in settings necessary

20. 20 Test evaluation Suggested correction factors: Correction for variations in vehicle speed during the test (according to ratio of chassis braking power) Correction for variations in test cell temperature, humidity and cabin temperature (according to ratio of variation in cooling capacity) C COPi-T1 Test bed temperature  C COPi-RH Test bed RH  C COPi-TC3 Cabin temperature 

21. 21 Test evaluation COP-Correction factors multiplication of the single correction factors is simple and no loss in accuracy against detailed simulation  Suggested look-up table for type approval

22. 22 Some test results ACEA (PSA) tested the method on 6 vehicles and found good repeatability: TUG performed 3 repetitions with final test procedure and had one outlier: Test 2 had a DPF regeneration during preconditioning but this hardly explains the difference Option: define maximum standard deviation from >3 tests

23. 23 Utility parameters Possible need to relate additional fuel consumption to vehicle size Depending on outcome of a pilot period Depending on the final goal of the procedure If needed, a proxy for vehicle size will be required. This proxy should be: Easy to measure Unambiguous If possible already included in the vehicle type approval Encouraging to fuel efficient MAC technology Continuous to avoid optimisation at utility steps

24. 24 Utility parameters (2) Possible utility parameters could be: Glazing area and inclination Footprint Interior volume (possibly based on footprint X height) Pan area Etc Or a combination of the above Pan area

25. 25 Utility parameters (3) Proposed approach: Collect a multitude of vehicle parameters during the pilot phase to enable the calculation of the correlation between these parameters and the additional fuel consumption This would of course need a means of correcting for various MAC technologies in some way  MAC and powertrain parameters also needed during pilot phase

26. 26 Utility parameters (4) Proposed parameters to be collected in the pilot phase: MAC component data Compressor swept volume Compressor type (piston, rotary vane, scroll, swash plate, swivel plate) Compressor displacement control (fixed or variable displacement) Compressor control type (internal control, external control) Clutched compressor (yes / no) Expansion valve type (fixed expansion valve (FXV), thermostatic expansion valve (TXV)) Receiver type (integrated / non integrated receiver) Internal heat exchanger, IHX (yes / no) Number of evaporators (single / double) Cabin airflow fan control (PWM / dropping resistor) Condenser airflow fan control (PWM / dropping resistor) Refrigerant type Refrigerant fill quantity Cabin air recirculation strategy description[1][1] MAC control strategy at low ambient temperatures (Auto MAC off at low ambient T/ MAC remains on at low ambient T) Vehicle data Vehicle body type (sedan, hatchback, stationwagon, SUV) Number of seats Interior volume[2][2] Vehicle footprint Vehicle height Glazing data; for every pane of glass / transparent plastic Size Inclination Thermal properties (Solar transmittance Tts according to ISO 13837) Tire size[3][3] Powertrain data Engine fuel type (petrol, diesel, CNG, LPG, etc.) Engine maximum power Engine displacement Engine number of cylinders Compressor drive method (belt, electric) Compressor drive ratio if belt driven (crank / compressor pulley ratio)3 Gearbox type (manual, automatic with torque converter, dual clutch, robotized manual)3 Base idle speed3 Gearbox ratios3 Final drive ratio3 [1][1] Possibly, in a follow-up project a control system strategy checklist could be defined which can be used in a “tick-box” manner to describe the control strategy. This would ensure that the control system strategy descriptions would all be in a similar format which should enable easier data handling and analysis. [2][2] Possibly calculated from a CAD model, (in or excluding seats and trim?) [3][3] This influences the time-speed pattern of the compressor over the test cycle as well as provide an estimate of the difference in CAP at idle and during the other phases of the test. List will be included in the final report

27. 27 Main open options Best preconditioning before soaking (NEDC?) Test low temperature behavior? How to handle battery SOC? Use cabin temperature or vent outlet temperatures as target? Which tolerances are reasonable for T’s and RH? How many test repetitions are necessary for stable result? (>2) Take glazing quality into consideration by correction factor or by change in MAC air mass flow? Start a pilot phase?

28. 28 Thank you for your attention and for the support in this project! MAC test cycle