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A6 – HVAC Selection – Grader’s Comments

• Everyone had good summaries on the relevant systems.
• It appears that most students believe that VAV is the "magic" system type and is good for almost every type of building. This results its constant winning in some team's matrices, which could be easily rejected under certain trivial scenarios (i.e. single-zone small building). To avoid such situation, a good approach is to try multiple cases and raise design scenarios to see if the result indeed makes sense. (2 points off for problematic logics)
• Only few teams commented on the eQUEST results. Students should at least explain or identify some of the numbers from the nice output files using your engineering judgment, not just putting them there for the sake of presentation. (3 points off for not explaining or identifying the eQUEST results.)

Shanghai Expo Pavilions

To continue the theme of the second assignment take a look through these buildings at the current World Exposition in Shanghai. Courtesy of Popular Science.

• How would you make them stand up?
• How would you heat and cool them?

There’s still lots of challenge in the building world!

Jim Mitchell

A5 – HVAC Variety – Grader Comments

• 
  Students have done a very good job in the numeric parameter part. All teams were able to find an extensive range of parameters for their systems.
  
• 
  The system descriptions show that students have difficulties understanding how each piece of the equipments in the systems work together. A good way to understand them is to look at the circulating path of working fluid (medium such as air, water or refrigerant that delivers heating and cooling). For this purpose, I have created a summary table for the major systems presented in class. Hopefully this will be helpful to students in developing the decision matrix for the next assignment.
  

A4 Grader Comments

The following (edited) comments from the grader may be useful.

• Students showed their best efforts in summarizing various types of structural systems and were able to select the "best solution" using a set of logical procedures.
  
• Every team was able to develop an extensive list of criteria to "grade" each plausible system.

The role of Numeric Decision Matrices

Ellen offered the following comments on decision matrices.  I’d note that you were not required to use a decision matrix on this assignment and did not lose points if you did not use one.  These comments are particularly useful for A6. [JEM]

• The following Wikipedia entry and article address why and how to develop such a numeric decision matrix.
  "Decision-matrix method" (http://en.wikipedia.org/wiki/Decision-matrix_method)
  
• "How to use a decision matrix to streamline your decision making process" (http://www.time-management-guide.com/decision-matrix.html)
  

If using a decision matrix avoid using any contradicting statements in the document such as the decision matrix shows one best alternative but another is proposed in the recommendation.

Teamwork

• All students have worked well with their teammates.

A3 Grader Comments

• Students presented a wide range of applications for the particular structural system assigned.
  
• Most students lost points due to the lack of detail discussion or comments in the following sections:
• system appropriateness for the typical uses
• typical values for the chosen numeric parameters
  
• Some teams forgot to look at the full range of applicable loads on the structural system. (Not all the loads are applicable for certain structural systems.)

A2 – Grader Comments

Grader comments for A2:

1. I was very impressed to see students going in depth studying the building of choice.

2. Not all the images are clearly labeled on the websites.

3. Only half the teams were able to identify the foundation type for the building. I suspect this is due to the fact that they have not taken courses in this area and it was not emphasized in previous courses. (Maybe we should turn this particular question into a multiple choice question?)

4. No team issues arise in this assignment.

 

Student suggestion summaries:

Students found making sense of the calculated numbers most difficult in this assignment. They would like to have a sample building with the required parameters to compare their numbers with. (JEM Nice idea – but why not ask me in class?)