IAQ and Pollution labs

A few notes about the IAQ lab and the upcoming water pollution lab.

IAQ:
- This lab was probably the most lopsided so far.  For many people, one mistake in this lab had a domino effect on the rest of the results.  If the rubric has that a value is "correct", it unfortunately does not leave room for partial credit, even if I can trace your work back to the error.

- Many people either mistyped or mis-converted the total heating gain from 280 kBTU/hr, should have been 280000 BTU/hr

- Many people mis-converted the electricity consumed by the chiller by using the BTU to watt-hr given.  However, the Ecooling has units of BTU/hr, and EER has units of BTU/watt-hr, so Ecooling/EER has units of (BTU/hr)*(watt*hr/BTU), or watt*hr/hr or just watt.  The instructions asked for kwatt*hr/hr, which required dividing by 1000.

- There seemed to be some confusion with the flow rates.  Put simply, Qe must always equal Qv.  The equation on the first page that Qv+Qr=Qe+Qr indicates this; if you subtract Qr from both sides of the equation, you're left with Qv=Qe.  Thinking about it physically, if if Qv was > Qe, there space would be pressurized, and if Qv were < Qe, it would be under vacuum.  Since we never want either of these, Qv and Qe will always be equal.  For question 3, the CO2 concentration should have decreased exponentially with increasing ventilation flow rate.


Water pollution lab due this week:
- Please make the memo a sheet in your workbook, formatted in the same way as previous memos, and answer all of the questions as described in the rubric.

- Format section: this is a more important section this time, please remember that your name and date should still be on each page.  On a similar note, organization is extremely important.  Each piece that is on the rubric should be clearly labeled in your document.

- Units are vitally important for this lab.  Make sure you clearly label all the conversions you make and label every result

- During lab, there were a lot of problems with entering the formulas into Excel.  Here's a couple features of your results to make sure you're on the right track:

1. The peak concentration should be about 10^-2, variable to the time step you use and different between Pottstown and Norristown, 
2. The rise and fall of the concentration should have about the same slope - if it is steeper on the upslope than the downslope, you've got a calculation error
3. Both Norristown and Pottstown concentrations should peak and return to virtually zero in the time specified

Again, please let us know if you have any questions!

-Anita