Hotter+Than+Hell

Brad Hosfeld, Nick Peterson, Emery Hunt, Tyler Graves


 * __Abstract:__**

The objective of this semester long project is est the occupant’s thermal comfort of a space. The space is a seating commons area in the Arts and Journalism building of Ball State University. It is our belief that this space, located directly next to a glazed (glass) curtain wall is thermally uncomfortable during periods of direct solar radiation exposure. In order to test this hypothesis we plan on using multiple methods, including electronic data collection, and survey of users. We believe that further analysis will find that the space is uncomfortable during periods of direct solar exposure causing individuals to actively avoid sunny areas, preferring to sit in the shaded seats within the space.

__**Introduction:**__

This hypothesis was developed through our subjective experience as users of the space. This problem could have been avoided if the designers would have taken greater care in the initial design phase. We plan to test our hypothesis with more than one method, to understand if different methods could yield different results.

__**Hypothesis:**__

The seating areas near the large glass curtain wall of the interior food court commons of the atrium becomes thermally uncomfortable for users when exposed to direct solar radiation.




 * __Methodology:__**

In order to test our hypothesis, we have given great thought to two methods we feel will yield the best results. Out first method is an occupant survey to gather data directly from those who use the space. The survey instrument is ASHRAE thermal sensation scale. The surveys will enable us to plot the periods of time in which seating areas near the glazing are thermally uncomfortable or comfortable for the occupants being surveyed.

The second method planned is use of the infrared thermometer gun to directly measure the temperature of the glass itself, a table directly next to the glass, and then, tables further away from the glass, proceeding table by table, farther into the atrium. Once data has been collected from both methods, we plan on placing the results from both methods together, occupant surveys and temperature collection, and comparing them side by side. We hypothesize that a table top temperature greater than 78 degrees Fahrenheit, or lower than 70 degrees Fahrenheit, will produce a thermally uncomfortable sensation for the occupant, the hypothesis is that a temperature between 70 and 78 degrees is the optimal thermal comfort area.Using the psycometric chart from ASHRAE, Chat 1 The area shaded in blue is what we have determined as our projected thermally comfort area.

From this we will be able to tell if the data from both methods yields a similar conclusion, or does not. In addition to these methods we also are looking at the possible use of a thermal comfort calculator found at ( [] ).

Chart 1.


 * __Process __**

To collect data that is relevant and can either prove or disprove our hypothesis.

Hypothesis

The seating areas near the large glass curtain wall of the interior food court commons of the atrium becomes thermally uncomfortable during the period of the day, in which it is exposed to direct solar radiation.

Methodology of the process

1. Occupant Survey

2. Temperature Collection

3. Direct Observation

Survey times will be from 11am to 1pm, Mondays through Fridays, any day that there is direct solar exposure on the area of study. A minimum of five (5) days of observation is required to get a reasonable result for the survey.

1A. Occupant Survey:

Survey: ASHRAE Thermal Sensation Scale

Please circle a choice that best describes how you feel.

Hot

Warm

Slightly Warm

Neutral

Slightly Cool

Cool

Cold

Using this basic survey tool will be able to pole the most honest answer from the occupants of the “sunny” zone. To get a good base of opinions of the thermal comfort of the study area, a minimum of one hundred (100) surveys need to be returned.

1B. Protocol for approaching Occupants.

“Hello, I am, I am from the School of Architecture and we are surveying occupants of the Atrium, to determine their level of individual Thermal Comfort. Would you like to participate in our survey? What I would like you to do is to circle one of the values that best describes how you are feeling right now.

1C. Variable Information on Person being surveyed.

After receiving the occupant’s survey, it will be noted if the occupant is male or female, and also what level of clothing are they wearing, jacket or no jacket.

A jacket wearing occupant will be counted as a plus one (+1) and a non-jacket wearing occupant will be counted as a zero (0).

2A. Temperature Collection

Collection times should be from 11am-1pm on sunny days. Thermal temperatures will be of the study area, and as a control from an area of the Atrium that has no solar exposure, to best chart the thermal differences between the sunny area and the non-sunny area. Temperature readings will need to be taken every fifteen (15) minutes to best track temperature changes.

Wet Bulb

Dry Blub

Hot Wire Anemometer

Temperature

3A. Direct Observation.

Attempt to discern any pattern of where patrons to the Atrium are sitting realative to the amount of solar radiation that is falling on them and the table top.

__**Analysis**__

When analyzing the data, we found no concrete evidence that solar heat gain or glare from the large curtain wall dictated where occupants of the space would sit. According to an occupant survey that utilized the ASHRAE thermal sensation scale, the majority of people felt either warm, slightly warm, neutral or slightly cool regardless of their location in relation to the curtain wall. Clo value and sex affected the occupant survey very little. According to our survey, 66% of males felt slightly warm, neutral, or slightly cool. The percentage of females that responded in the same fashion was 64%. Also there were no people, male or female, that chose hot or cold (the two extremes of the scale). || 0  ||
 * Male Thermal Sensation Scale || 1 clo value  ||  .5 clo value  ||
 * Hot ||  ||  0  ||  0  ||  0  ||
 * Warm ||  ||  13  ||  5  ||  8  ||
 * Slightly Warm || 18  ||  12  ||  5  ||
 * Neutral ||  ||  9  ||  5  ||  4  ||
 * Slightly Cool || 8  ||  2  ||  7  ||
 * Cool ||  ||  5  ||  0  ||  5  ||
 * Cold ||  ||  0  ||
 * Cold ||  ||  0  ||

Figure 1: Male Thermal Sensation Scale




 * Female Thermal Sensation Scale || 1 clo value  ||  .5 clo value  ||
 * ||  ||   ||  1  ||  0.5  ||
 * Hot ||  ||  0  ||  0  ||  0  ||
 * Warm ||  ||  14  ||  6  ||  8  ||
 * Slightly Warm || 13  ||  10  ||  3  ||
 * Neutral ||  ||  8  ||  3  ||  5  ||
 * Slightly Cool || 9  ||  5  ||  4  ||
 * Cool ||  ||  3  ||  1  ||  2  ||
 * Cold ||  ||  0  ||  0  ||  0  ||

Figure 2: Female Thermal Sensation Scale



While our occupant survey focused more on a qualitative means to determining thermal comfort, we also used more quantitative methods to attempt to determine whether the occupants of the space were comfortable. This method consisted of measuring the exterior temperature, the wet-bulb and dry-bulb interior temperature, the temperature of the curtain wall itself, the temperature of the tabletops that occupants were sitting at, and the airspeed inside the space. As stated before, we used the infrared thermometer, the dry-bulb anemometer, and the dry-bulb/wet-bulb temperature gauge to compile this data. Our measurements were recorded in five relatively sunny days in November. For our measurements in both wet-bulb and dry-bulb interior temperature, we found the temperature to consistently remain at a comfortable level throughout our testing period. The lowest wet-bulb temperature was 66 degrees Fahrenheit while our highest was 73 degrees Fahrenheit. In regards to dry-bulb temperature, our lowest measurement was 69 degrees Fahrenheit while our highest was 75.5 degrees Fahrenheit. The exterior temperature remained fairly consistent between the five days ranging from 55 degrees to 58 degrees. Our measurements for airflow in the space also fluctuated very little and remained at a comfortable level somewhere between 1cfm and 2cfm.





In order to get a better feel of the temperature directly where the occupants were sitting, we used the infrared thermometer to measure the temperature of the tabletops in the testing area. While these temperatures were slightly higher than the wet-bulb and dry-bulb temperatures, they also fluctuated very little. There was also very little change from the temperature of tabletops in the shade to the temperature of tabletops in the sun. All the measured tabletop temperatures fell somewhere between 72 degrees Fahrenheit and 82 degrees Fahrenheit.



We used this same piece of equipment to measure the temperature of the glazing to determine whether this would affect people’s thermal comfort. These values were slightly lower than the tabletop temperatures and had about the same amount of fluctuation. The lowest measured glazing temperature was 67 degrees Fahrenheit and the highest was 79 degrees Fahrenheit.



Located below are our specific measured data on exterior temperature, glazing temperature, tabletop temperature, wet-bulb interior temperature, and dry-bulb interior temperature on the specific dates and at specific times.
 * 2-Nov ||   || Weather: Sunny || Ext Temp: 56 ||   ||   ||
 * || Tabletop Temp  ||  Glazing Temp  ||  Wet Blub  ||  Dry Blub  ||  Airflow  ||
 * || 72  ||  73  ||  66  ||  69  ||  1.2  ||
 * || 72  ||  71  ||  66.5  ||  70  ||  1.2  ||
 * || 71  ||  74  ||  68  ||  71  ||  1.5  ||
 * || 73  ||  70  ||  69  ||  71  ||  1.6  ||
 * || 74  ||  71  ||  69.5  ||  72.5  ||  1.3  ||
 * || 71  ||  69  ||  68  ||  70  ||  1.2  ||
 * || 75  ||  72  ||  68  ||  70  ||  1.4  ||
 * || 73.5  ||  71.5  ||  70  ||  72.5  ||  1.2  ||
 * || 74.5  ||  72  ||  70.5  ||  73  ||  1.7  ||
 * 4-Nov ||   || Weather: Sunny || Ext Temp: 58 ||   ||   ||
 * || Tabletop Temp  ||  Glazing Temp  ||  Wet Blub  ||  Dry Blub  ||  Airflow  ||
 * || 70  ||  71  ||  68  ||  71  ||  1.1  ||
 * || 70.5  ||  73  ||  68.5  ||  71.5  ||  1.4  ||
 * || 71  ||  73  ||  68  ||  71.5  ||  1.4  ||
 * || 71  ||  73.5  ||  71  ||  73  ||  1.7  ||
 * || 72  ||  72  ||  72  ||  73.5  ||  2  ||
 * || 72  ||  72.5  ||  71  ||  72.5  ||  1.8  ||
 * || 73  ||  72  ||  71  ||  72  ||  1.3  ||
 * || 72  ||  71  ||  70  ||  71.5  ||  1.3  ||
 * || 71.5  ||  72  ||  71  ||  72.5  ||  1.5  ||
 * 5-Nov ||   || Weather: Sunny || Ext Temp: 55 ||   ||   ||
 * || Tabletop Temp  ||  Glazing Temp  ||  Wet Blub  ||  Dry Blub  ||  Airflow  ||
 * || 81  ||  78  ||  71  ||  73.1  ||  1.7  ||
 * || 82  ||  79  ||  72  ||  75  ||  1.4  ||
 * || 78  ||  75  ||  73  ||  74.5  ||  1.3  ||
 * || 77  ||  74.8  ||  72  ||  74  ||  1.2  ||
 * || 76  ||  74.5  ||  72  ||  75.5  ||  1.3  ||
 * || 74  ||  73  ||  72  ||  74.5  ||  1.6  ||
 * || 73.5  ||  71  ||  72  ||  75.2  ||  1.2  ||
 * || 73.5  ||  71.5  ||  72.8  ||  74.5  ||  1.2  ||
 * || 72  ||  71  ||  72  ||  75.5  ||  1.1  ||
 * 6-Nov ||   || Weather: Sunny || Ext Temp: 56 ||   ||   ||
 * || Tabletop Temp  ||  Glazing Temp  ||  Wet Blub  ||  Dry Blub  ||  Airflow  ||
 * || 74  ||  71  ||  69  ||  71  ||  1.2  ||
 * || 74.5  ||  72  ||  69  ||  72  ||  1.3  ||
 * || 74  ||  69  ||  69  ||  72  ||  2  ||
 * || 71  ||  69  ||  69  ||  70  ||  1.4  ||
 * || 71.5  ||  67  ||  68  ||  70  ||  1.3  ||
 * || 72.5  ||  69  ||  68  ||  70  ||  1  ||
 * || 72  ||  69  ||  68  ||  70  ||  1.2  ||
 * || 73.5  ||  70.5  ||  67  ||  70  ||  1.3  ||
 * || 74.5  ||  72  ||  67  ||  70  ||  1.7  ||
 * 9-Nov ||   || Weather: Sunny || Ext Temp: 55 ||   ||   ||
 * || Tabletop Temp  ||  Glazing Temp  ||  Wet Blub  ||  Dry Blub  ||  Airflow  ||
 * || 79  ||  79  ||  70.5  ||  73  ||  1.7  ||
 * || 81  ||  77.5  ||  69.5  ||  73.5  ||  1.4  ||
 * || 79  ||  76.5  ||  71  ||  73  ||  1.3  ||
 * || 78  ||  77  ||  70.5  ||  73.5  ||  1.2  ||
 * || 77  ||  75  ||  73  ||  75  ||  1.3  ||
 * || 75  ||  74  ||  71.5  ||  74  ||  1.6  ||
 * || 76.5  ||  74.5  ||  70  ||  73.5  ||  1.2  ||
 * || 74.5  ||  70  ||  73  ||  75  ||  1.2  ||
 * || 74  ||  73  ||  71  ||  73  ||  1.1  ||
 * || 72  ||  69  ||  68  ||  70  ||  1.2  ||
 * || 73.5  ||  70.5  ||  67  ||  70  ||  1.3  ||
 * || 74.5  ||  72  ||  67  ||  70  ||  1.7  ||
 * 9-Nov ||   || Weather: Sunny || Ext Temp: 55 ||   ||   ||
 * || Tabletop Temp  ||  Glazing Temp  ||  Wet Blub  ||  Dry Blub  ||  Airflow  ||
 * || 79  ||  79  ||  70.5  ||  73  ||  1.7  ||
 * || 81  ||  77.5  ||  69.5  ||  73.5  ||  1.4  ||
 * || 79  ||  76.5  ||  71  ||  73  ||  1.3  ||
 * || 78  ||  77  ||  70.5  ||  73.5  ||  1.2  ||
 * || 77  ||  75  ||  73  ||  75  ||  1.3  ||
 * || 75  ||  74  ||  71.5  ||  74  ||  1.6  ||
 * || 76.5  ||  74.5  ||  70  ||  73.5  ||  1.2  ||
 * || 74.5  ||  70  ||  73  ||  75  ||  1.2  ||
 * || 74  ||  73  ||  71  ||  73  ||  1.1  ||
 * || 75  ||  74  ||  71.5  ||  74  ||  1.6  ||
 * || 76.5  ||  74.5  ||  70  ||  73.5  ||  1.2  ||
 * || 74.5  ||  70  ||  73  ||  75  ||  1.2  ||
 * || 74  ||  73  ||  71  ||  73  ||  1.1  ||

In conclusion, the original thought was that a two story, East facing, floor to ceiling glass curtain wall would make the Arium thermally uncomfortable to be in certain locations during the day. The next step was to define “uncomfortable.” Things that we tried to address were temperature, humidity, air speed, as well as patterns of sun and shade. We hoped that since glare is subjective, that we could deduce it by observing “comfortable” people who were sitting in the shade versus “comfortable” people who were sitting in the sun. The surveys we made up were to gauge the thermal comfort level of the atrium occupants. The results were not quite as expected. Even though our data showed some would-be influential information (a table top temperature fluctuation of 10 degrees) It did not seem to dictate where people sat. This led us to believe that while glare was definitely being experienced (being an entity of degree) it was overcome by the air quality control systems (dry/wet bulb temperature, air speed, humidity) that can be seen in our data as much more stable. Thus glare, in itself, is not enough of an issue to make patrons sit in the sun versus the shade in this particular situation.
 * __Conclusion__**


 * __References__**

//Mechanical and Electrical Equipment for Buildings//, 11th edition: Grondzik, Kwok, Stein, and Reynolds; John Wiley & Sons, Hoboken, NJ, 2010