IS428 2016-17 Term1 Assign3 Tan Kee Hock

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To be a Visual Detective: Detecting spatio-temporal patterns

Overview

After the successful resolution of the 2014 kidnapping at GAStech’s Abila, Kronos office, GAStech officials determined that Abila offices needed a significant upgrade. At the end of 2015, the growing company moved into a new, state-of-the-art three-story building near their previous location. Even though the employee morale rose somewhat with the excitement of the new building, there are still a few disgruntled employees in the company.

The new office is built to the highest energy efficiency standard, but as with any new building, there are still several HVAC issues to work out. The building is divided into several HVAC (heating, ventilation, and air conditioning) zones. Each zone is instrumented with sensors that report building temperatures, heating and cooling system status values, and concentration levels of various chemicals such as carbon dioxide (abbreviated CO2) and hazium (abbreviated Haz), a recently discovered and possibly dangerous chemical. CEO Sten Sanjorge Jr. has read about hazium and requested that these sensors be included. However, they are very new and very expensive, so GAStech can afford only a small number of sensors.

With their move into the new building, GAStech also introduced new security procedures, which staff members are not necessarily adopting consistently. Staff members are now required to wear proximity (prox) cards while in the building. The building is instrumented with passive prox card readers that cover individual building zones. The prox card zones do not generally correspond with the HVAC zones. When a prox card passes into a new zone, it is detected and recorded. Most, but not all, areas are still open to staff members even if they forget their prox cards. People are somewhat careless with their prox cards, but some diligent staff members will go to the security desk and pick up a new prox card if their old one is mislaid. As part of the deal to entice GAStech to move into this new building, the builders included a free robotic mail delivery system. This robot, nicknamed Rosie, travels the halls periodically, moving between floors in a specially designed chute. Rosie is equipped with a mobile prox sensor, which identifies the prox cards in the areas she travels through.


The Task

As an expert in visual analytics, you have been hired to help GAStech understand its operations data. In this assignment, you are given two weeks of building and prox sensor data. Can you use visual analytics to identify typical patterns of and issues of concern?

You will be asked to answer the following types of questions:

  1. What are the typical patterns in the prox card data? What does a typical day look like for GAStech employees?
  2. Describe up to ten of the most interesting patterns that appear in the building data. Describe what is notable about the pattern and explain its possible significance.
  3. Describe up to ten notable anomalies or unusual events you see in the data. Prioritize those issues that are most likely to represent a danger or a serious issue for building operations.
  4. Describe up to five observed relationships between the proximity card data and building data elements. If you find a causal relationship (for example, a building event or condition leading to personnel behavior changes or personnel activity leading to building operations changes), describe your discovered cause and effect, the evidence you found to support it, and your level of confidence in your assessment of the relationship.

Background

Heating, ventilation and air conditioning (HVAC) is the technology of indoor and vehicular environmental comfort. Its goal is to provide thermal comfort and acceptable indoor air quality.
Key Measurement attributes and their significance

  1. Lights Power [W]
  2. Power used by the lights in the zone
  3. Equipment Power [W]
  4. Power used by the electric equipment in the zone
  5. Thermostat Temp [C]
  6. Temperature of the air inside the zone
  7. Thermostat Heating Setpoint [C]
  8. Heating set point schedule for the zone
  9. Thermostat Cooling Setpoint [C]
  10. Cooling set point schedule for the zone
  11. VAV Availability Manager Night Cycle Control Status
  12. On/off status of the HVAC system during periods when the system is normally scheduled off. The night cycle manager cycles the HVAC system to maintain night and weekend set point temperatures.
  13. VAV_SYS SUPPLY FAN:Fan Power [W]
  14. Power used by the HVAC system fan
  15. BATH_EXHAUST:Fan Power [W]
  16. Power used by the bathroom exhaust fan
  17. VAV REHEAT Damper Position
  18. Position of the zone's air supply box damper. 1 corresponds to fully open, 0 corresponds to fully closed
  19. REHEAT COIL Power [W]
  20. Power used by the zone air supply box reheat coil
  21. VAV_SYS HEATING COIL Power [W]
  22. Power used by the HVAC system heating coil
  23. VAV_SYS Outdoor Air Flow Fraction
  24. Percentage of total air delivered by the HVAC system that is from the outside
  25. VAV_SYS Outdoor Air Mass Flow Rate[kg/s]
  26. Flow rate of outside air entering the HVAC system
  27. VAV_SYS COOLING COIL Power [W]
  28. Power used by the HVAC system cooling coil
  29. VAV_SYS AIR LOOP INLET Temperature [C]
  30. Mixed temperature of air returning to the HVAC system from all zones it serves
  31. VAV_SYS AIR LOOP INLET Mass Flow Rate [kg/s]
  32. Total flow rate of air returning to the HVAC system from all zones it serves
  33. VAV_SYS SUPPLY FAN OUTLET Temperature [C]
  34. Temperature of the air exiting the HVAC system fan
  35. VAV_SYS SUPPLY FAN OUTLET Mass Flow Rate [kg/s]
  36. Total flow rate of air delivered by the HVAC system fan to the zones it serves
  37. RETURN OUTLET CO2 Concentration [ppm]
  38. Concentration of C02 measured at the zone's return air grille
  39. SUPPLY INLET Temperature [C]
  40. Temperature of the air entering the zone from its air supply box
  41. SUPPLY INLET Mass Flow Rate[kg/s]
  42. Flow rate of the air entering the zone from its air supply box
  43. Mechanical Ventilation Mass Flow Rate [kg/s]
  44. Ventilation rate of the zone exhaust fan
  45. Hazium Concentration
  46. Something
  47. Drybulb Temperature [C]
  48. Drybulb temperature of the outside air
  49. Water Heater Tank Temperature [C]
  50. Temperature of the water inside the hot water heater
  51. Water Heater Gas Rate [W]
  52. Rate at which the water heater burns natural gas
  53. Supply Side Inlet Mass Flow Rate [kg/s]
  54. Flow rate of water entering the hot water heater
  55. Supply Side Inlet Temperature [C]
  56. Temperature of the water entering the hot water heater
  57. HVAC Electric Demand Power [W]
  58. Total power used by the building's HVAC system including coils, fans and pumps.
  59. Total Electric Demand Power [W]
  60. Total power used by the building
  61. Loop Temp Schedule
  62. Temperature set point of the hot water loop. This is the temperature at which hot water is delivered to hot water appliances and fixtures.
  63. Water Heater Setpoint
  64. Water heater set point temperature
  65. DELI-FAN Power [W]
  66. Power used by the deli exhaust fan
  67. Pump Power [W]
  68. Power used by the hot water system pump Water Heater


The data

You will have the following data and supporting information at your disposal:

  • A building layout for the GAStech offices, including the maps of the prox zones and the HVAC zones
  • A current list of employees, roles, and office assignments
  • A description of the data formats and fields provided
  • Proximity sensor data for each of the prox zone regions
  • Proximity sensor data from Rosie the mobile robot
  • HVAC sensor readings and status information from each of the building’s HVAC zones
  • Hazium readings from four sensors.

The datasets have been zipped and uploaded into the dropbox of e-learn (LMS).

Data Cleaning

Visualisation

The visualization is based on the category of the data. The breakdown of the proposed visualization is as shown below.

  1. Homepage
  2. Building Data Explorer : Air Supply Controls / Water Supply Controls / Fan Controls / Coil Controls / Additional System Controls
  3. Employee Movement Explorer
  4. Variable Explorer

The original dataset is overwhelming. There are over 400 different columns. To make the analysis more meaningful, the data columns has to be group logically based on the purpose of the sensor/data point. I have grouped the data into 6 different categories, namely;

  1. Air Supply data
  2. Water Supply data
  3. Fan data
  4. Coil data
  5. Additional System data
  6. Employee Proximity Card data
MA2 image 69.PNG

Homepage
Purpose / Description
The homepage is the landing page you will see when you use this Visualisation tool. The data explorery tools are all displayed on the homepage. This homepage makes use of the Tableau Dashboard and its action functions to enable interactivity. It is to serve as a "Home" panel for this visualisation and it would enable the user ease of navigation betweent the dashboards.
MA2 image 69.PNG

Building Data Explorer : Air Supply Controls / Water Supply Controls / Fan Controls / Coil Controls / Additional System Controls
Purpose / Description
Interactive Technique
Employee Movement Explorer
Purpose / Description
Interactive Technique
Variable Explorer
Purpose / Description
Interactive Technique

Use Case

Findings - Task #1

What are the typical patterns in the prox card data? What does a typical day look like for GAStech employees?

Findings - Task #2

Describe up to ten of the most interesting patterns that appear in the building data. Describe what is notable about the pattern and explain its possible significance.

Serial Measurement Category Description and Significance
1 Thermostat Setting The general setting for the thermostat heating and cooling setpoints tend to be opposite of each other. When the heating set point is being set to a higher point, the cooling setpoint will be set to a lower point. This is normally because the user is trying to adjust the temperature of the air within the zone. Naturally, when you want the place to be cooler, you will set the heating point at a lower point, and the cooling point to be at a higher point. This is to produce an equilibrium temperature within the zones. You see that the temperature of the air is between the two setpoints.

MA2 image 69.PNG
However in the month of June, the period of 7th to 10th. The behaviour of the thermostat setting seems to be off the norms. It betrays the general behaviour which is shown in the rest of the month. As the heating setpoint increases, the cooling setpoint increases as well. The general temperature of the air within the zones seems to increase significantly during mid-day. It peaks up as much as to 28.88°C. The average temperature of the air in the zones hovers around 24°C. This is approx. 4°C above the norm. The average temperature in Singapore, especially during the hottest month,February, is around 27°C. The observation here is definitely something worth investigating
MA2 image 69.PNG
The behaviour is consistent throughout all the floors and its zone.
MA2 image 69.PNG
There are potential reasoning to this cause.

  1. Inappropriate handling of the thermostat controls
  2. Severe weather conditions - eg Extremely Cool/Hot Weather (Unlikely)

Significance
The thermostat settings are vital to ensure that the building is properly heated. If the temperature gets too high in the building, and without properly ventilation, will pose potential safety risks to the employees. If the temperature is unable to be regulated induce flavour working conditions, it will likely to cause not just unhappiness but health issues to the employees.

2 Mechanical Ventilation Mass Flow Rate This measurement tells us how much air is flowing through the zone exhaust fan. In the month of June, in particular, there is some inconsistency for the readings on two particular weekends, namely 4th-5th June and 11th-12th June. In general, the readings of this specific measurement has its own cycle within the day. Naturally, it would be lower on the weekends. However, the 2 weekends in June, displays very different reading. The first weekend shows a reading that is below the average while the second weekend shows a reading that is significantly higher than the average.

MA2 image 69.PNG
You can also observe that the readings are consistent throughout the weekdays and weekends. During the weekday, the flow rate generally increases during mid-day (Possibly due to the hot weather). On the weekend the pattern is very different. MA2 image 69.PNG
Significance
The readings of the amount of air flowing through the zone exhaust fan can tell us if the building is well ventilated. It indicates the movement of air. Since this observation happens on the weekend, potentially the lack of human activity may be correlated to the lower flow rate. But the difference of flow rate in two separate weekends remains questionable. The flow rate indicates blockage and ventilation of the building. If there is build-up of dust/blockages or animal movement, the flow rate inevitably will be affected. A higher flow rate in the weekend without human activity can potentially indicate faulty sensors or errors in the equipment which results in abnormal control of the ventilation.

3 Bath_Exhaust:Fan Power This is the measurement of the power used by the bathroom fans. The power indicates usage of the bathroom. There is consistent use of the bathroom throughout the weekday. On the weekend, especially Saturdays (4th and 11th), the usage drops drastically after 1600H.

MA2 image 69.PNG
Significance
The power usage indicates the use of the bathroom. You notice that during the weekday, the bathrooms are consistently used at a similar rate. As explained by the consistent colour throughout the working day. This reading tells us the employee's movement and activity of a typical day in the company. The consistent use of bathrooms, indicate human activity in the building as well. Furthermore, it can be used to indicate the employee's productivity, if there are potential cases of "slacking off"/"malingering".

4 Dry Bulb Temperature The dry-bulb temperature (DBT) is the temperature of air measured by a thermometer freely exposed to the air but shielded from radiation and moisture. DBT is the temperature that is usually thought of as air temperature, and it is the true thermodynamic temperature. Thus, this reading tells us the relative weather condition of outside of the building.

MA2 image 69.PNG
As shown in the picture, the readings are very consistent throughout the month of June, you can see that the temperature generally goes up during noon. This reading strongly correlates to the time of the day. Generally, you would expect the temperature to go up during mid-day.
Significance
The dry bulb temperature is essential for the HVAC system, as the reading can be used to evaluate the effectiveness of the HVAC system within the building. We can measure how effective the HVAC system is, in regulating the internal building temperature.

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Findings - Task #3

Describe up to ten notable anomalies or unusual events you see in the data. Prioritize those issues that are most likely to represent a danger or a serious issue for building operations.

Priority Measurement Category Description and Significance
1 VAV_SYS Supply Fan Outlet Mass Flow Rate This reading tells us the total rate of air delivered by the HVAC system fan to the zone it serves. The data collected in the month of June is not showing consistent results.

The readings do tally with the VAV_Sys Supply Fan Outlet:Power.
MA2 image 69.PNG
MA2 image 69.PNG
The readings intensify in 2 particular periods, 7th-8th June and 10th-13th June. During 7th-8th June (Tuesday to Wednesday), the reading intensifies in the early hours and late night. This is an abnormal phenomenon. This is telling us that more air is being delivered by the HVAC system fan when there is no supposed employee during this period. The second period, 10th-13th June, shows intensified readings consistently from 10th June evening to 13th June Morning (Friday to Monday).
Signifiance
The readings do not seem to tally with the supposed work shifts of employees. There seems to be an increased flow of air during the period where no one supposed to be there. There are multiple possibilities which may have caused such data readings.

  1. Faulty Sensors causing false readings (Unlikely)
  2. Faulty Equipment

This reading is important because it will indicate the overall system health of the HVAC fans. It tells us if the HVAC fans are working harder. It also indicates if the HVAC system's ability to maintain the building's internal temperature/ventilation.

2 Deli-Fan Power This reading tells us the power used by the deli exhaust fan. There are some suspicious data points with regards to the use of Deli-Fan.

MA2 image 69.PNG
The fan usage seems to be consistently high during a Sunday(5th and 12th June). The readings do not seem to tally with the increased human activities during the weekday. The inconsistent readings do not seem to establish any form of correlation with the human activity. But rather, the pattern of seem to be established by other unknown factors. Signifiance
Exhaust fans are health indicators of the overall HVAC systems. Should the exhaust fans power usage display sporadic patterns, they indicate abnormalities within the HVAC system. Furthermore, they help to regulate the airflow for the HVAC system. The poor performance of Exhaust fans will significantly hamper the HVAC's ability to regulate internal building temperature.

3 VAV_SYS Heating Coil Power There is completely 0 power used for the heating coil. This is entirely not possible as the HVAC system seem to be working properly. Thus, there is very little prove that the Heating Coil is broken/faulty.

MA2 image 69.PNG
Signifiance
This is very likely to be a faulty Power Usage sensor. Although this reading does not seem to affect the rest of the system, an investigation in the faulty sensor is recommended. If there are external forces in play which results in the faulty sensor, then it is very likely this cause will impact other parts of the HVAC system. For example, water leakage in specific part of the building which caused the sensor to be spolit, etc.

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Findings - Task #4

Describe up to five observed relationships between the proximity card data and building data elements. If you find a causal relationship (for example, a building event or condition leading to personnel behavior changes or personnel activity leading to building operations changes), describe your discovered cause and effect, the evidence you found to support it, and your level of confidence in your assessment of the relationship.

Conclusion

My initial work - https://public.tableau.com/views/MA_3_Final/Overview?:embed=y&:display_count=yes

Visualisation Software

To perform the visual analysis, students are encouraged to explore any one or a combination of the following software:

  • Tableau
  • JMP Pro
  • Qlik Sense
  • Microsoft Power BI

One of the goals of this assignment is for you to learn to use and evaluate the effectiveness of these visual analytics tools.


Submission details

This is an individual assignment. You are required to work on the assignment and prepare submission individually. Your completed assignment is due on 24th October 2016, by 12.00 noon.

You need to edit your assignment in the appropriate wiki page of the Assignment Dropbox. The title of the wiki page should be in the form of: IS428_2016-17_T1_Assign3_FullName.

The assignment 3 wiki page should include the URL link to the web-based interactive data visualization system prepared.


Assignment 3 Q&A

Need more clarification, please feel free to pen down your questions.

  1. What is Hazium? Hazium is a (fictitious) chemical that has become a recent concern on the island of Kronos. Not much is known about its effects, but it is suspected that Hazium is not good for people.
  2. There are a few extra building file data fields in the .json dataset that do not appear in the .csv data. These extra data fields are actually valid for the building for the dates and times they were recorded, but they will not add significantly to your analysis. So for this assignment, please just use the data fields included in the .csv file.
  3. Can you provide more info on the data provided in the mobile proximity card data? Are the x,y coordinates bound to a normal (x,y) plane, where in this case the plane is the floor maps? The (x,y) coordinates are bound to a normal plane. The (x,y) plus the floor number would identify a specific location. The lower left of the provided map is (0,0) and the upper right is (189,111).
  4. In some cases, data is reported for some sensors and not others, or it is documented but not reported. Where can we find this data? Please use the data fields you have available to perform your investigation. In general, the documented set of attributes may not be reported for all zones.
  5. What does the (x,y) coordinates represent for the mobile robot sensor? The (x,y) coordinates for these reading represent the location of the mobile sensor.
  6. Sometimes, mobile prox data for a prox card repeats multiple times in a minute. Does this indicate the number of seconds that the prox card was within range of the sensor? No. Multiple readings do not indicate what fraction of the minute that the mobile sensor was in proximity of the prox card.
  7. In some cases, the value of the VAV Availability Manager Night Cycle On/Off is 2. Is this a valid value? Yes.
  8. Does F_3_Z_9 VAV Damper Position mean F_3_Z_9 VAV REHEAT Damper Position? Yes.