Problem Identification for Product Development Opportunities of Wine Refrigerators

EXAMENSARBETE INOM DESIGN OCH PRODUKTFRAMTAGNING, AVANCERAD NIVÅ, 30 HP

STOCKHOLM, SVERIGE 2018

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MALIN ERLANDSSON PETRA NÄSSTRÖM

Master of Science Thesis

Division of Applied Thermodynamics and Refrigeration

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Master of Science Thesis TRITA-ITM-EX 2018:492

Problem Identification for Product Development Opportunities of Wine Refrigerators

Petra Näsström

Malin Erlandsson Approved

2018-06-26 Examiner

Viktoria Martin Supervisor

Viktoria Martin

Commissioner

Electrolux AB

Supervisor at Industry Urban Wählby

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First and foremost, we would like to thank Urban Wählby who was our supportive supervisor throughout this master thesis helping us getting in contact with the right people and give good advice for upcoming tasks. We also want to extend our gratitude to Electrolux for taking us in and all help received from the Global Advanced Development for Food Preservation department, this was an educative experience. Primarily, we want to acknowledge Daniel Fridenäs and Andreas Aschan for the continuous help with understanding how a regular refrigerator is constructed, how it works, and how the system can be improved. Similarly, Tomas Ahlman who helped us with programming throughout the project.

Lastly, we would also want to thank Viktoria Martin that has been our supervisor from KTH.

Malin Erlandsson, Petra Näsström

Stockholm Sweden, 2018-05-31

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Both value and flavor of wines can improve with time if stored properly. The factors with the most profound effect on the wine are light, humidity, temperature, vibrations, and ventilation. Light consisting of shorter wavelengths, under 450 nm, are dangerous for wine and can destroy the structure in wine. The humidity is supposed to be kept between 50-80 %, mainly to prevent the wine cork from drying out, since this would result in a shrinkage that will let in air to the bottle.

When considering temperature, the ideal maturing temperature is 12-14 °C for both reds and whites. It is also essential to keep the wine at a stable temperature; it should not fluctuate more than 1.5 °C per day or 2-3 °C over a year. Larger amplitudes of vibrations cause an increased structural change in wine molecules. Therefore, they should be kept as small as possible.

Ventilation is required since a reasonably small closed space with high humidity leads to a mold- prone environment which could be devastating to the wine.

The wine market is shifting from bulk wine to becoming more wine enthusiast focus where it is believed the importance of a wine refrigerator will increase with this shift. The wine business is not scientifically originated. Several requirements are mainly “hearsay” and “common knowledge”.

The aim of this paper was to identify scientifically founded facts to product develop wine refrigerators for a global market.

Four different wine refrigerators called A, B, C, and D, from different brands, were tested in a laboratory from a wine requirement perspective with a focus on temperature, humidity, and electricity consumption. All tests were conducted for 24 hours. Both temperature and humidity were logged every 10 seconds and results were processed in MATLAB and presented in graphs.

It was found that cabinets with separators held a more accurate temperature than those without one. It was also found that most of them held a temperature within the allowed fluctuation interval. Moreover, the air temperature fluctuation did not significantly affect the temperature inside the wine bottle indicating it is not important to further improve.

The humidity was tested both with and without load but did not give a significant difference, which indicates the cabinets does not have a unique system to add humidity to the cabinet.

Overall, all cabinets except one reached an average of at least 50 % relative humidity, which is the minimum requirement. The functionality of the humidity system of each unit is in question.

Most surprisingly, the high electricity consumption for all of the wine fridges entails potential improvement area of the cooling system that uses more energy than what is thought to be needed.

A comparison with a regular domestic refrigerator shows great potential for improvement, especially since a wine fridge only needs to perform a temperature of 12 °C, while a domestic fridge keeps a temperature of approximately 4 °C. The vast amount of energy use could also be because of inadequate insulation, with leakage through or around the glass door. A closer look at the gaskets showed small unsealed spots where the gasket was not tightly against the cabinet, enabling ambient air to leak in. Overall, the energy consumption results highlighted an inefficient cooling cycle.

The found development opportunity is to include a variable-speed compressor into the refrigeration unit to maintain proper internal climate regarding temperature, humidity, and energy demand. Furthermore, the results of this thesis highlight the light blockage solutions which seem non-considered in the tested refrigerators and what was found in the market.

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Både värde och smak hos vin kan öka över tid om det lagras på ett korrekt sätt. De faktorer som har mest påverkan på vinet är ljus, luftfuktighet, temperatur, vibrationer och ventilation. Ljus som består av korta våglängder under 450 nm är farliga för vinet och kan förstöra dess struktur.

Luftfuktigheten bör hållas mellan 50 - 80 %, detta framförallt då korken annars kan torka ut vilket då kan leda till att korken krymper och luft kommer in i vinflaskan. Gällande temperaturen, är det ideala intervallet vid åldring av vin är 12 - 14 °C för både vitt och rött vin. Det är även viktigt att hålla vinet på en stabil temperatur, det bör inte fluktuera mer än 1,5 °C per dygn eller 2 - 3 °C över ett år. Ett forskningsarbete om vibrationer påvisar att ökade vibrationsamplituder orsakar ökade strukturella förändringar i vinets molekyler, därför bör de vara så små som möjligt. Ventilation är nödvändigt eftersom ett litet slutet utrymme med hög luftfuktighet leder till en miljö med mögelbenägenhet, vilket kan vara förödande för vinet.

Vinmarknaden skiftar från bulkviner till att bli mer vinentusiast-fokuserade i köp där vikten av vinkyl tros öka i detta skifte. Hela vinindustrin är inte tungt forskningsgrundad där mycket tillgänglig kunskap ”hörsägen” och ”allmän kunskap”. Målet med denna studie var därmed att identifiera vetenskapligt grundade fakta för att produktutveckla vinkylar på en global marknad.

Fyra olika vinkylar från olika märken, kallade A, B, C och D, testades utifrån ett vinperspektiv i ett laboratorium med fokus på temperatur, luftfuktighet och energikonsumtion. Samtliga tester utfördes under en period på 24 timmar där temperatur och luftfuktighet loggade var 10e sekund där resultaten sedan behandlades i MATLAB och presenterades i grafer. Det kom fram att skåp med separatorer höll en mer exakt temperatur än dom utan. Majoriteten av skåpen höll temperaturen inom det tillåtna fluktuationsintervallet under ett dygn. Slutligen visade resultaten att temperaturfluktuationerna i luften inte påverkade temperaturen i vinet inuti en vinflaska marginellt varpå slutsatsen blev att detta inte skall vara ett fokusområde vid fortsatt utveckling.

Alla vinkylar testades med och utan last och påvisade inte en signifikant skillnad vilket indikerar att respektive kabinett inte inkluderas av ett unikt luftfuktighetssystem som tillför fukt till skåpet.

Alla kylar utom en uppnådde ett genomsnitt av minst 50 % relativ luftfuktighet som definierades till minimikravet. Funktionen av respektive fuktighetssystem är ifrågasättbar där lite eller noll information gås att få.

Mest överraskande, resultaten indikerade en hög energikonsumtion för alla vinkylar vilket indikerar en förbättringspotential av kylsystemet då den förbrukar mer energi än vad som är nödvändigt. Vid en jämförelse med ett vanligt konsumentkylskåp vidare indikerar samma slutsats då den ofta använder mindre energi trots att den skall åskakomma temperaturer runt 4 °C i jämförelse med en vinkyl som skall hålla temperaturer runt 12 °C. Stora energikonsumtionen kan också härstamma från bristfällig isolering med läckage genom och runt glasdörren. Empiriskt syntes små hålrum genom isolerande packningen där luft kunde läcka igenom. Däremot tros den största energikonsumtionen vara ett resultat av en ineffektiv kylcykel.

Funna utvecklingsmöjligheten är att inkludera en variabel-hastighetskompressor i kylcykeln för att upprätthålla lämpligt internt klimat med avseende på temperatur, luftfuktighet och energikonsumtion. Avhandlingen påvisar även att ljusblockeringslösningen verkar ogenomtänkt i respektive testad kabinett och vad som är funnet på marknaden.

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Abbreviation

AI Artificial Intelligence

CFC Chlorofluorocarbon

COP Coefficient of Performance

GWP Global Warming Potential

IoT Internet of Things

KPI Key Performance Index

LED Light-Emitting Diode

RFID Radio Frequency Identification

RH Relative Humidity

rpm Rounds per minute

TEC Thermoelectric cooling

UPC Universal Product Code

UV Ultraviolet

VCC Vapor Compression Cycle

Units

dB Decibel

Gal Galileo [0.01 m/s²]

h Hour

Pa Pascale

pH Potential of Hydrogen

V Voltage

W Watt

Prefix

k Kilo

M Mega

Other

|𝜀𝑘| Compressor energy

|q1| Heat rejected from the condenser

|q2| Heat collected from the fridge compartment

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ACKNOWLEDGEMENT ... IV

ABSTRACT ... V

SAMMANFATTNING ... VI

NOMENCLATURE... VII

TABLE OF CONTENTS ... IX

LIST OF FIGURES ... XI

LIST OF TABLES... XIV

1. INTRODUCTION ... 1

1.1 BACKGROUND ... 1

1.2 AIMS & OBJECTIVES... 1

1.3 LIMITATIONS ... 3

1.4 METHODOLOGY ... 3

2. LITERATURE REVIEW ... 5

2.1 WINE SCIENCE ... 5

2.1.1 Market ... 5

2.1.2 Supply Chain ... 6

2.1.3 Wine Requirements ... 8

2.1.4 Storage... 9

2.1.5 Serving ... 10

2.2 COOLING TECHNOLOGY ... 12

2.2.1 Absorption... 12

2.2.2 Thermoelectric Cooling ... 13

2.2.3 Vapor-Compression Cycle... 14

2.2.4 Comparison ... 18

3. CUSTOMER ... 20

3.1 CUSTOMER REVIEWS ... 20

4. MARKET ... 22

4.1 WINE STORAGE FEATURES ... 23

4.1.1 Temperature Zones ... 23

4.2.2 Light ... 23

4.2.3 Humidity and Ventilation... 27

4.2.4 Vibration ... 28

4.2.5 Noise... 29

4.2 MAPPING ... 29

4.4 PROSPECTS ... 31

5. LABORATORY METHODOLOGY ... 34

5.1 TEMPERATURE MEASUREMENT ... 35

5.1.1 Temperature Measurement 1 ... 35

5.1.2 Temperature Measurement 2 ... 35

5.1.3 Temperature Measurement 3 ... 36

5.1.4 Expectations... 37

5.2 HUMIDITY MEASUREMENT ... 37

5.2.1 Expectations... 38

5.3 ELECTRICITY CONSUMPTION MEASUREMENT ... 38

5.3.1 Electricity Consumption Measurement 1 ... 38

5.3.2 Electricity Consumption Measurement 2 ... 38

5.3.3 Expectations... 38

5.4 SENSITIVITY ANALYSIS ... 39

6. RESULTS AND DISCUSSION ... 40

6.1 CUSTOMER ... 40

6.2 MARKET... 41

6.3 LABORATORY RESULTS ... 41

6.3.1 Temperature Measurement ... 42

6.3.2 Humidity Measurement ... 60

6.3.3 Electricity Consumption Measurement ... 69

6.3.4 Sensitivity Analysis ... 73

6.4 IMPROVEMENT AREAS ... 74

7. CONCLUDING REMARKS ... 76

7.1 FUTURE WORK... 77

BIBLIOGRAPHY ... 78

APPENDICES ... I

APPENDIX I ... I

APPENDIX II ... IV

Unit A ... IV

Unit B ...V

Unit C ... VI

Unit D ...VIII

APPENDIX III ... X

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FIGURE 1. THE THREE FOUNDATIONS FOR THE THESIS WHERE THE AIM IS TO FIND THE SOLUTION IN THE FIGURE DISPLAYED

IN THE MIDDLE WHERE THE CUSTOMER, MARKET, AND TECHNOLOGY IS CORRELATED. ... 2

FIGURE 2. VISUALISATION OF THE METHODOLOGY USED TO ATTACK RESEARCH PROBLEM AND WHERE RESPECTIVE PHASE IS REPRESENTED IN THE THESIS. ... 3

FIGURE 3. SUPPLY CHAIN FROM GRAPE TO CONSUMPTION (GONCHARUK, 2017). ... 7

FIGURE 4. A GRAPH REPRESENTING THE AMOUNT OF OXYGEN THAT REACHES THE WINE FOR DIFFERENT STOPPERS (SCHMITT, 2017). ... 10

FIGURE 5. SENSORY INTENSITY IN WHITE WINES DEPENDING ON SERVING TEMPERATURE WHERE THE DIFFERENT LETTERS INDICATE SIGNIFICANT DIFFERENCES (P ≤ 0.05); N = 72 (ROSS ET AL., 2008). ... 11

FIGURE 6. SENSORY INTENSITY IN RED WINES DEPENDING ON SERVING TEMPERATURE WHERE THE DIFFERENT LETTERS INDICATE SIGNIFICANT DIFFERENCES (P ≤ 0.05); N = 72 (ROSS ET AL., 2008). ... 12

FIGURE 7. AN ILLUSTRATION OF THE ABSORPTION REFRIGERATOR (GRANRYD, 2014). ... 13

FIGURE 8. THE PRINCIPAL OF A THERMOELECTRIC MODULE (THE ELECTRIC ENERGY, 2015). ... 14

FIGURE 9. SCHEMATIC FIGURE OVER A VAPOR-COMPRESSION CYCLE (EKROTH ET. AL, 2013). ... 15

FIGURE 10. PRESSURE AND ENTHALPY DIAGRAM OF THE REFRIGERATIVE PROCESS (GRANRYD ET. AL, 2011). ... 15

FIGURE 11. THE LINES SHOW THE UV PROTECTION PERFORMANCE FOR THE DIFFERENT SINGLE GLASSES CONSERNING THE WAVELENGTHS. C STANDS FOR CLEAR GLASS, UVG STANDS FOR UV GLASS, COL REPRESENTS COLORED GLASS, AND C + UVF REPRESENTS CLEAR GLASS INCLUDED WITH AN UV FILM (KIM ET AL., 2010). ... 24

FIGURE 12. VISUALIZATION OF THE PERFORMANCE FOR THE PAIR GLASS COMBINATIONS IN RELATIONS TO THE WAVELENGTHS. C STANDS FOR CLEAR GLASS, UVG STANDS FOR UV GLASS, UVF REPRESENTS UV FILM, AND COL REPRESENTS COLORED GLASS (KIM ET AL., 2010). ... 25

FIGURE 13. THE TRANSMITTANCE FOR DIFFERENT LEVELS OF LIGNIN IN COMBINATION WITH CELLULOSE (SADEGHIFAR ET, AL., 2017). ... 25

FIGURE 14. LIGHT EMITTANCE FROM THREE DIFFERENT LIGHT SOURCES COMPARED TO SUNLIGHT IN IN RELATIONS TO THE WAVELENGTH IN (NM) AND IN THE INTENSITY IN ARBITRARY UNITS (ARB) (SMITH, 2016). ... 26

FIGURE 15. RELATIVE SPECTRAL RADIANCE DISTRIBUTION FOR COMMON LED LIGHT SOURCES AND THEIR WAVELENGTH (KHANH ET AL., 2014). ... 27

FIGURE 16. THE BOX WITH CLAY BALLS THAT IS USED TO HUMIDIFY SINGLE TEMPERATURE ZONE WINE FRIDGES (EUROCAVE, N.D.). ... 28

FIGURE 17. A CLAY CYLINDER FILLED WITH WATER TO MAKE SURE THE HYGROMETRY WITHIN THE CABINET IS CORRECT (EUROCAVE, N.D.). ... 28

FIGURE 18. DIMENSIONS OF A STANDARD BORDEAUX BOTTLE IN INCHES (SARAH, 2014). ... 30

FIGURE 19. GRAPH OF THE TEMPERATURES INSIDE UNIT A AT AMBIENT TEMPERATURE OF 10 °C. ... 43

FIGURE 20. THE TEMPERATURES PROFILE INSIDE CABINET A AT AMBIENT TEMPERATURE OF 22 °C. ... 43

FIGURE 21. GRAPH OF THE TEMPERATURES INSIDE UNIT A AT AMBIENT TEMPERATURE OF 38 °C... 44

FIGURE 22. GRAPH OF THE TEMPERATURES INSIDE UNIT B AT AMBIENT TEMPERATURE OF 10 °C. ... 45

FIGURE 23. THE TEMPERATURE PROFILES INSIDE UNIT B AT AMBIENT TEMPERATURE OF 22 °C. ... 46

FIGURE 24. GRAPH OF THE TEMPERATURES INSIDE CABINET B AT AMBIENT TEMPERATURE OF 38 °C ... 46

FIGURE 25. THE TEMPERATURES INSIDE THE C CABINET AT AMBIENT TEMPERATURE OF 10 °C... 48

FIGURE 26. GRAPH OF THE TEMPERATURES INSIDE CABINET C AT AMBIENT TEMPERATURE OF 22 °C. ... 48

FIGURE 27. PLOT OF THE TEMPERATURES INSIDE CABINET C AT AMBIENT TEMPERATURE OF 35 °C. ... 49

FIGURE 28. RESULTS FROM THE TEMPERATURES INSIDE UNIT D AT AMBIENT TEMPERATURE OF 10 °C ... 50

FIGURE 29. GRAPH OF THE TEMPERATURES INSIDE UNIT D AT AMBIENT TEMPERATURE OF 22 °C. ... 51

FIGURE 30. THE TEMPERATURES INSIDE UNIT D CABINET AT AMBIENT TEMPERATURE OF 32 °C. ... 52

FIGURE 31. THE CABINET A TEMPERATURES WELL AS THE AMBIENT AND BOTTLE TEMPERATURES DISPLAYED AT THE LEFT Y-AXIS IN RELATION TO RELATIVE HUMIDITY ON THE RIGHT Y-AXIS THROUHGOUT 24 HOURS. ... 53

FIGURE 32. A GRAPH OF THE CABINET B, AMBIENT, AND BOTTLE TEMPERATURES IN RELATION TO RELATIVE HUMIDITY AND TIME. ... 54

FIGURE 33. THE CABINET, AMBIENT, AND BOTTLE TEMPERATURES IN RELATIONS TO RELATIVE HUMIDITY THROUGHOUT THE 24 HOUR PERIOD FOR UNIT C. ... 55

FIGURE 34. A GRAPH OF THE CABINET, AMBIENT, AND BOTTLE TEMPERATURES IN RELATIONS TO THE RELATIVE HUMIDITY THROUGHOUT A 24 HOUR PERIOD. ... 56

FIGURE 35. TEMPERATURE MEASUREMENT 3 WITH A 50 % BOTTLE CAPACITY LOAD FOR UNIT A. THE LEFT Y-AXIS

DISPLAYS THE TEMPERATURE AND THE RIGHT Y-AXIS THE HUMIDITY... 57

FIGURE 36. TEMPERATURE PROFILE FOR THE B UNIT FOR A 50 % BOTTLE CAPACITY LOAD. THE LEFT Y-AXIS DISPLAYS THE

TEMPERATURE AND THE RIGHT Y-AXIS THE HUMIDITY. ... 58

FIGURE 37. UNIT C WITH A 50 % BOTTLE CAPACITY LOAD. THE LEFT Y-AXIS DISPLAYS THE TEMPERATURE AND THE RIGHT Y-AXIS THE HUMIDITY. ... 59

FIGURE 38. TEMPERATURE MEASUREMENT 3 WITH A 50 % BOTTLE CAPACITY LOAD. THE LEFT Y-AXIS DISPLAYS THE

TEMPERATURE AND THE RIGHT Y-AXIS THE HUMIDITY. ... 60

FIGURE 39. HUMIDITY AND TEMPERATURE FOR THE AMBIENT ROOM AND INSIDE THE A UNIT. THE RIGHT Y-AXIS SHOWS THE TEMPERATURE, LEFT Y-AXIS SHOWS THE RELATIVE HUMIDITY AND X-AXIS IS TIME. ... 61

FIGURE 40. HUMIDITY AND TEMPERATURE WITH 50 % LOAD THROUGHOUT 24 HOUR PERIOD BOTH FOR THE AMBIENT ROOM AND INSIDE UNIT A. THE RIGHT Y-AXIS SHOWS THE TEMPERATURE, LEFT Y-AXIS SHOWS THE RELATIVE

HUMIDITY, AND X-AXIS IS TIME. ... 62

FIGURE 41. HUMIDITY AND TEMPERATURE FOR THE AMBIENT ROOM AND INSIDE UNIT B. THE RIGHT Y-AXIS SHOWS THE TEMPERATURE, LEFT Y-AXIS SHOWS THE RELATIVE HUMIDITY AND X-AXIS IS TIME. ... 63

FIGURE 42. HUMIDITY AND TEMPERATURE WITH 50 % LOAD THROUGHOUT 24 HOUR PERIOD BOTH FOR THE AMBIENT ROOM AND INSIDE UNIT B. THE RIGHT Y-AXIS SHOWS THE TEMPERATURE, LEFT Y-AXIS SHOWS THE RELATIVE

HUMIDITY, AND X-AXIS IS TIME. ... 64

FIGURE 43. HUMIDITY AND TEMPERATURE WITH 0 % LOAD FOR THE AMBIENT ROOM AND INSIDE UNIT C. THE RIGHT Y-AXIS SHOWS THE TEMPERATURE, LEFT Y-AXIS SHOWS THE RELATIVE HUMIDITY AND X-AXIS IS TIME. ... 65

FIGURE 44. HUMIDITY AND TEMPERATURE WITH 50 % LOAD THROUGHOUT 24 HOUR PERIOD BOTH FOR THE AMBIENT ROOM AND INSIDE UNIT C. THE RIGHT Y-AXIS SHOWS THE TEMPERATURE, LEFT Y-AXIS SHOWS THE RELATIVE

HUMIDITY, AND X-AXIS IS TIME. ... 66

FIGURE 45. THE RIGHT Y-AXIS SHOWS THE TEMPERATURE, LEFT Y-AXIS SHOWS THE RELATIVE HUMIDITY AND X-AXIS IS TIME. ... 67

FIGURE 46. THE RIGHT Y-AXIS SHOWS THE TEMPERATURE, LEFT Y-AXIS SHOWS THE RELATIVE HUMIDITY, AND X-AXIS IS TIME FOR THE UNIT D WITH 50% LOAD. ... 68

FIGURE 47. A GRAPH OF THE CABINET HUMIDITY COMPARED TO THE AMBIENT HUMIDITY. ... 69

FIGURE 48. ELECTRICITY CONSUMPTION OF UNIT A FOR DIFFERENT AMBIENT TEMPERATURES AND A HORIZONTAL LINE FOR THE RATED CONSUMPTION. ... 70

FIGURE 49. ELECTRICITY CONSUMPTION OF UNIT B FOR THE RESPECTIVE AMBIENT TEMPERATURES AND A HORIZONTAL LINE FOR THE RATED CONSUMPTION... 70

FIGURE 50. ELECTRICITY CONSUMPTION OF UNIT C FOR DIFFERENT AMBIENT TEMPERATURES AND A HORIZONTAL LINE FOR THE ASSUMED RATED CONSUMPTION. ... 71

FIGURE 51. ELECTRICITY CONSUMPTION OF UNIT D FOR DIFFERENT AMBIENT TEMPERATURES AND A HORIZONTAL LINE FOR THE RATED CONSUMPTION. ... 72

FIGURE 52. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT A AT AMBIENT TEMPERATURE OF 10 °C ... IV

FIGURE 53. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT A AT AMBIENT TEMPERATURE OF 22 °C ... IV

FIGURE 54. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT A AT AMBIENT TEMPERATURE OF 38 °C ...V

FIGURE 55. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT B AT AMBIENT TEMPERATURE OF 10 °C ...V

FIGURE 56. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT B AT AMBIENT TEMPERATURE OF 22 °C ... VI

FIGURE 57. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT B AT AMBIENT TEMPERATURE OF 38 °C ... VI

FIGURE 58. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT C AT AMBIENT TEMPERATURE OF 10 °C ...VII

FIGURE 59. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT C AT AMBIENT TEMPERATURE OF 22 °C ...VII

FIGURE 60. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT C AT AMBIENT TEMPERATURE OF 35 °C ... VIII

FIGURE 61. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT D AT AMBIENT TEMPERATURE OF 10 °C ... VIII

FIGURE 62. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT D AT AMBIENT TEMPERATURE OF 22 °C ... IX

FIGURE 63. ZOOMED GRAPH OF THE TEMPERATURES INSIDE UNIT D AT AMBIENT TEMPERATURE OF 32 °C ... IX

FIGURE 64. UNIT A WHERE THE BOTTLE TEMPERATURE IS VISLUALISED IN RESPECT TO AIR TEMPERATURE FLUCTUATIONS.X

FIGURE 65. UNIT B WHERE THE BOTTLE TEMPERATURE IS VISLUALISED IN RESPECT TO AIR TEMPERATURE FLUCTUATIONS. X

FIGURE 66. UNIT C WHERE THE BOTTLE TEMPERATURE IS VISLUALISED IN RESPECT TO AIR TEMPERATURE FLUCTUATIONS. ... XI

FIGURE 67. UNIT D WHERE THE BOTTLE TEMPERATURE IS VISLUALISED IN RESPECT TO AIR TEMPERATURE FLUCTUATIONS. ... XI

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TABLE 1. THRESHOLD QUALITIES FOR THE FOUR PHYSICAL REQUIREMENTS. ... 8

TABLE 2. CLIMATE CLASSES WITH THEIR RESPECTIVE TEMPERATURE RANGE (EUROPEAN UNION, 2010). ... 22

TABLE 3. SPECIFICATIONS OF TEST MODELS TOGETHER WITH THEIR SPECIFICATIONS. ... 34

TABLE 4. ATTRIBUTES AND FEATURES FOR RESPECTIVE WINE REFRIGERATOR. ... 35

TABLE 5. DISTRIBUTION OF THERMOELEMENTS IN TEMPERATURE MEASUREMENT 1... 35

TABLE 6. DISTRIBUTION OF THERMOELEMENTS IN TEMPERATURE MEASUREMENT 2... 36

TABLE 7. THE LOAD BOTTLE VOLUME FOR 50 % FILLED UNIT... 36

TABLE 8. DISTRIBUTION OF THERMOELEMENTS IN TEMPERATURE MEASUREMENT 3... 37

TABLE 9. DIRECT INACCURACIES DETECTED IN THE TEST RIG FOR THE RESPECTIVE MEASUREMENT DEVICE. ... 39

TABLE 10. FOUND REVIEWED FEATURES WITH KPIS FOR STANDARD AND PREMIUM WINE REFRIGERATORS RESPECTIVELY. ... 40

TABLE 11. UNIT A RESULTS FROM TEMPERATURE MEASUREMENT 1, MINIMUM (MIN), MAXIMUM (MAX), AND AVERAGE (AVG) TEMPERATURE INSIDE THE UNIT FOR THE RESPECTIVE AMBIENT TEMPERATURE SETTING. ... 42

TABLE 12. UNIT B WITH ITS MINIMUM (MIN), MAXIMUM (MAX), AND AVERAGE (AVG) TEMPERATURE INSIDE THE UNIT FOR THE RESPECTIVE AMBIENT TEMPERATURE SETTING. ... 45

TABLE 13. RESULTS FROM TEMPERATURE MEASUREMENT 1 FOR THE UNIT C WITH MINIMUM (MIN), MAXIMUM (MAX), AND AVERAGE (AVG) TEMPERATURE INSIDE THE UNIT FOR THE RESPECTIVE AMBIENT TEMPERATURE SETTING ... 47

TABLE 14. UNIT D WITH RESULTS FROM TEMPERATURE MEASUREMENT 1, WITH MINIMUM (MIN), MAXIMUM (MAX), AND AVERAGE (AVG) TEMPERATURE INSIDE THE UNIT FOR THE RESPECTIVE AMBIENT TEMPERATURE SETTING... 50

TABLE 15. MINIMUM (MIN), MAXIMUM (MAX) TEMPERATURE TOGETHER WITH THE RESULTING TEMPERATURE FLUCTUATION DETECTED DURING THE TESTING PERIOD FOR RESPECTIVE WINE REFRIGERATOR. ... 56

TABLE 16. RELATIVE HUMIDITY, AVERAGE (AVG), MINIMUM (MIN), AND MAXIMUM (MAX) IN THE A CABINET AND IN THE AMBIENT ROOM FOR THE RESPECTIVE LOAD LEVEL. ... 61

TABLE 17. RELATIVE HUMIDITY, AVERAGE (AVG), MINIMUM (MIN), AND MAXIMUM (MAX) IN UNIT B CABINET AND IN AMBIENT ROOM. ... 63

TABLE 18. RELATIVE HUMIDITY, AVERAGE (AVG), MINIMUM (MIN), AND MAXIMUM (MAX) IN UNIT C CABINET AND IN AMBIENT ROOM. ... 65

TABLE 19. RELATIVE HUMIDITY, AVERAGE (AVG), MINIMUM (MIN), AND MAXIMUM (MAX) IN THE UNIT D CABINET AND IN AMBIENT ROOM. ... 67

TABLE 20. ENERGY CONSUMPTION PER DAY FOR EVERY AMBIENT CONDITIONS AND FOR EVERY WINE REFRIGERATOR UNIT. ... 69

TABLE 21. THE ELECTRICITY CONSUMPTION FOR BOTH LOADS WITH A UNIFIED INTERNAL TEMPERATURE OF 12 °C FOR RESPECTIVE BRAND. ... 72

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There are several active wine refrigeration companies on the 2018 market. Some of the current wine refrigerator actors in the market that sells wine fridges are experienced in manufacturing and home appliance companies such as Miele, Liebherr, Severin among others. Some of the actors are wine enthusiasts striving for a great wine experience such as Climadiff and Tastvin. Moreover, some actors enter the market with a kitchen design perspective such as EPOQ. All are highlighting the importance to understand the thermodynamic competences applied to the wine refrigeration units where some units might have optimization opportunities.

1.1 BACKGROUND

Wine is a traditional beverage with a long history. One can find different wines and wine styles produced throughout the world including still table wines, sparkling wines, and fortified wines.

(Tao et al., 2013). The earliest archaeological evidence has been found in China 7000 B.C, and the Romans were the first empire of which wine was stored (Hames, 2012). Chapmans initially handled wines which excluded and narrowed the wine storage market. However, wine fridges became increasingly common in the mid-20th century (Johnson, 1989). It is essential to maintain a constant temperature, humidity, and minimize the light reaching the bottles to pursue a proper aging process for proper long-term aging. Majority of wines are aimed to be consumed within 24 hours of purchase whereas premium wines can age and improve both its flavor and value with time (Baldy, 2009). Premium, luxury, and fine wines all aims to describe similar wine types whereas bulk and commercial wines are of the other end. Even though the wine types are often mentioned, there is no precise definition of which wines are of which type. Premium wines are not directly linked to a higher price but rather the aging potential in comparison to the commercial table wines (Werdelmann, T, 2014). However, if premium wines are not stored in optimum conditions, the wines can deteriorate. The interest of fine wines has continued to increase and the need for proper storage is therefore high (Cusin et al., 2015 & Thanh et al., 2018).

Wine refrigerators come in a variety of configurations, from a whole wine cellar to small refrigeration units in a tabletop size. Further, the models can be divided into; Under counter, which means their height is the same as a typical height countertop; Freestanding, meaning a stand-alone unit that is not dependent on its surroundings. Moreover, Built-in solutions; where the wine refrigerator is meant to be a part of the other interior and have the same outer design as the kitchen for example. A wine fridge is attractive for a variety of customer groups including restaurants, private housing societies, and consumer on both professional and novice level.

Suitability for the units differs with customer requirements. How accessible the bottles shall be, how much wine shall one be able to store, slidable shelves etcetera. Private customers will most likely not have the same behavior as restaurants or professional wine investors. Restaurants have a higher turnover of its wine which shall be displayed for the restaurant customers whereas wine investors are more likely to nurture their wines with time with less turnover (Wine Spectator, 2011).

1.2 AIMS & OBJECTIVES

The market, customers, and technology for wine refrigerators will constitute the foundation of this thesis where the aim is to identify development opportunities within the current refrigerators and improve the future solutions. The foundations are correlated and interact with

each other which is why the primary competitive product is believed to consider all of these aspects as seen in Figure 1.

FIGURE 1. THE THREE FOUNDATIONS FOR THE THESIS WHERE THE AIM IS TO FIND THE SOLUTION IN THE FIGURE

DISPLAYED IN THE MIDDLE WHERE THE CUSTOMER, MARKET, AND TECHNOLOGY IS CORRELATED.

The principle technology will be studied to understand the whole system of the cooling cycle and the parameters, required by the wine, of which are problematic to fulfill will be determined. Four wine refrigerators from different brands with differentiating internal volume and features will be tested to understand the current market situation. For example, they are featured with different number of temperature zones. One of them is a single zone, one is a dual zone without a separator, one is a dual zone with a separator, and the last one has three zones.

The market will be mapped by analyzing the current wine refrigerators available on the market today (2018). A state-of-the-art looks into current technologies from several brands to get an overview of the possible differentiation. It is also essential to understand the customer experience for different customer segments to determine the needs and demands.

The expected impact of the study is to find knowledge and innovation opportunities within wine fridges for Electrolux. To see how it is in line with their values and goals towards the consumer market. The project will present proposed development areas with measurable parameters regarding temperatures, humidity, and energy performance. The expected outcome is to use the proposed development areas of this thesis and develop solutions to create a more competitive product.

Therefore, the key research question is as follows:

What are the critical improvement areas for wine refrigerators?

- The objectives can be divided into the following:

- Outline the best conditions for storage of wine and if it differs depending on wine sort.

- The primary customer needs for a wine fridge.

- Map the current market situation.

- Current features of wine refrigerators.

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- The correlation between current wine fridges and the needs of wine.

1.3 LIMITATIONS

The study is strictly limited to still table wines where other wine types might occur but is not of primary focus. Similarly, standalone wine coolers are of primary focus whereas other technologies will be mentioned but not in-depth analyzed. However, to not discard other designs entirely, will one built in solution be tested. The tests performed in this thesis are limited to four wine refrigerators, all from different brands.

The market mapping is conducted with 76 different wine refrigerators from 16 different brands.

1.4 METHODOLOGY

The study has been divided into four different phases to meet the outlined thesis objectives in a structured manner. The process is displayed Figure 2.

FIGURE 2. VISUALISATION OF THE METHODOLOGY USED TO ATTACK RESEARCH PROBLEM AND WHERE RESPECTIVE PHASE

IS REPRESENTED IN THE THESIS.

PHASE 1

Firstly, an in-depth analysis of wine science and wine fridge cooling technologies will be conducted. Furthermore, the cooling cycle within the wine refrigerator with its components will be analyzed. Lastly, the requirements of the wine for storage purposes will be recognized. See chapter 2. Literature Review.

PHASE 2

In this phase, a state of the art analysis of wine fridge technologies and the cooling cycle together with innovative features will be identified. An analysis will be performed to understand the current market situation. Lastly, customer needs will be analyzed via customer reviews, to

understand what is of importance for potential customers. See chapters 3. Customer and 4.

Market.

PHASE 3

Tests will be carried out to see how well the current wine fridges live up to the needs of wine, determining problem areas in need of improvement. Thermoelements, hygrometers, and an energy-meter will be used with different configurations to map the performance of the wine refrigerators. The data will be processed in MATLAB_R2016b. See chapters 5. Laboration Methodology and 6.3 Laboration Results.

PHASE 4

Phase 4 is set aside for revision work and overall finalizing tasks for the master thesis work. The customer needs and requirements correlated to the tested technology findings will constitute the foundation for improvement possibilities of the wine fridge. See chapters 6. Results and Discussion and 7. Concluding Remarks.

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The foundation in a wine refrigerator is built on requirements of wine. Therefore, it is essential to understand the factors that are crucial for wine to mature correctly, especially if it is an expensive wine seen as an investment. By recognizing the importance of external influence as well as where the market is now, a better ground to build “the future” can be made. Furthermore, to achieve the essential storing condition, cooling is acquired. There are different types of cooling cycles available on the market where refrigeration systems mainly use vapor-compression cycle.

2.1 WINE SCIENCE

Wines can, if stored correctly, improve its flavor and value with time and if stored incorrectly, deteriorate rapidly. The factors with the most profound effect on the wine are light, humidity, vibrations, and temperature. If wine is exposed to these factors within damageable levels, the compound of wine will change, lose its structure and hence decrease its quality. The technical difference between a wine cooler and a food fridge is mainly drawn from the climatic requirements of the wine, and the difference is usage. Wine refrigerators are often designed with a more appealing design since it is a hobby object often placed in homes to be displayed.

Wine is a complex fluid where the aging process is difficult to predict fully. Red wine contains water, alcohol, phenolic compounds, sugar, and other compounds (Fernandes et al., 2017).

2.1.1 MARKET

Historically, the wine was consumed geographically close to the production where the majority of the share was located in Europe. Even though globalization, migration waves after the World Wars, and increasing continental trades the wine market exports did not flourish until the 1990s.

Nowadays more than two-fifths of all wines consumed globally are produced outside of Europe still owning the market lead. The majority of the production volume originates in France, Italy, Portugal, and Spain emphasizing the European market lead to a more specific region. However, the European share of the world's production volume has dropped from 77.3 % to 50.1 % between 1860-2016 in the prominent wine producing countries France, Italy, Portugal, and Spain.

Similarly, the wine consumption has dropped throughout the years where an average yearly consumption per capita was 120.3 liters in 1860 in France, decreasing to 44.0 liters per year in 2016. The decreasing consumption trends are similar for the prominent wine producing countries. However, wine consumption per capita is increasing in the non-traditional wine countries in Europe such as Sweden, Germany, Croatia, and the Netherlands among others (Anderson et al., 2017).

The North American average yearly wine consumption has increased from 1.1 liters per capita to 10.6 between the 1860s and 2016. North America is also increasing its production volume share from 0.4 % in 1870 to 11.1 % in 2016 emphasizing a market interest (Anderson et al., 2017). It is believed the wine consumption will continue to increase in North America and shift from regular wines to premium wines (Kelley et al., 2015).

Asia, and most prominently China, has an evolving market growing each year. However, there has been a distinction where one should not view the future in the eyes of a western market. The country has no deep tradition in drinking wine with food as westerners do. On the demand side one can see a shift of wine consumption from ‘government wealth’-driven to 'private wealth'- driven. The growing income makes fine wines accessible to the middle class which further increases the demand. Furthermore, red wine is in China socially perceived as of higher status; it