The following is posted as an announcement in VistaBB, but is repeated here.
Jim Mitchell
As of 11/27/2010 at 5PM I updated the calculated grade. It is now based on:
As before these are “raw” grades without corrections for the “free” attendance and dropped lowest grades.
Jim Mitchell
The final discussion topic is to write on something we learned relating to our major. Since I am a B&E studying operations management the material has not directly related to this course. Any suggestions for those in the "other" category?
If you think there hasn’t been anything that relates to your major you might want to write about what you think your major could offer to Civil, Architectural or Environmental engineers.
Jim Mitchell
“I noticed in cell F36 of the results tab has the amount of CO2 in tons but in cell F37 it divides cell H27 over F36. This would be incorrect because in cell F36 the units are in tons and not Megatons like in cell H27. So I changed the units in cell F36 to Megatons. Am I right by doing this or was it just some kind of typo with the units that were labeled.? “
There is a typo for the units for cell F36. Dr. Spatari meant metric tons. The results from the eio-lca model are given in metric tons (not megatons).
I am having problems with question two in the lab. the equation for Ecooling is E-cooling.=,E-heatgain.+,E-ventilationair.−,E-exhaustionair. The problem with this is Qe and Qv are always equal to each other. Therefore, when you find their mass by multiplying by density their are always equal. Then when you find their energies by multiplying each by their masses then they are equal again. So, E-ventilationair ends up being equal to E-exhaustionair end up being equal to each other and cancel each other out when calculating for Ecooling and Ecooling ends up being equal to E-heatgain. When calculating utility cost you multiply the E-lectricty by the Electricity price. So, the electricity consumed and the utility cost ends up not being dependent on a change in Qe or Qv. Please let me know if I have some part of this equation wrong because when I am changing my Qv nothing is happening to the utility cost or the electricity consumed.
The difficulty you’re having stems almost certainly from the fact that you’re not incorporating the fact that the temperature coming in is not the same as the temperature leaving. If you use those temperatures the energy is different and you’ll have meaningful numbers.
Jim Mitchell
In Question 2, are you assuming that the ventilation airflow rate, Qv, is equal to the total airflow rate, Qt? And then again, similiar to Question 1, assuming that Qv is equal to Qe?
The total air flow rate is defined in the problem definition to be a constant, 7,200 m^3/h. As the ventilation (and therefore exhaust since they are equal) increases the recirculated air must therefore decrease.
In the instructions sheet, you gave us an equation for the energy carried by airflow which I understand. But what do the T and W in the equation stand for?
T is the temperature in degrees Fahrenheit
W is the air humidity in lb-water/lb-dry-air
Yes, there will be a lecture on Monday 11/22. A panel of faculty and graduate students, led by the department head Dr. Haas, will discuss graduate study and research.
Jim Mitchell
If you’d like to have your own hard hat (with a CAEE logo I believe), they are available for $10 from Dr. Robert Brehm in his office - Alumni Engineering 273G
Email – rfb23@drexel.edu
Jim Mitchell
“What is the unit for the emission rate of CO2, the hand out stated it is 15 ppm-h/people, but for quest 1, when I have to calculate Number of people *(E CO2/ V), the unit for the result is ppm/h. I cannot understand how the unit for ppm-h/people * people is ppm/h, not ppm-h.”
Kinman Leung has sharp eyes and has learned to check units – bravo! He caught a typo. The correct units are indeed ppm/h*people.
“One of the grading criteria in lab 7 for the memo is "Relation to site visit", however we never visited the site as apart of the lab? Are you asking how does this relate when we go to the recreation center on our own time? Thanks for your time.”
Oops. When we did this last spring we matched the site visit to the hydrology computation. This fall we pushed it back a week. You may ignore that question. Apologies.
I’ve updated the gradebook calculation and made the all the graded discussions and assignments to date visible. The calculated grade (unadjusted for allowed misses) is composed of:
Jim Mitchell
