1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Indoor air quality measurement

  1. Aug 14, 2012 #1
    Hi guys
    I am assigned to do the indoor air quality measurement in 5 buildings which are 2 academic buildings, one residence, a library and a gym. I have to establish a methodology to measure CO2, temperature, humidity, air movement as well as particulates. I have 2 months time to measure and analyse data to represent buildings with poor indoor air quality. My problem is establishing the time and duration of measurement for each parameter in these buildings. Moreover I do not have any idea in which areas it would be better to do the measurements (for example one classroom in first and top floor?). I got confused because I think 2 month is not enough for measuring all these parameters in 4 buildings.Do you have any idea?I appreciate your help!
  2. jcsd
  3. Aug 15, 2012 #2
  4. Aug 15, 2012 #3


    User Avatar
    Gold Member

    I am just wondering if you would need to measure occupied and unoccupied, so as to have some sort of baseline for comparison.
    And perhaps keep of record of conditions exterior to the building to explain any glitches that could occur in the data.

    Just my 2 cents.
  5. Aug 15, 2012 #4
    Basically, the great outdoor is about 400 PPM CO2 that is our base line. Indoors 600 to 800 PPM is very well ventilated. There are standards for the acceptable levels. The data logger are used to measure over a long enough period to determine the occupied/ not occupied levels for CO2, Temperature & relative Humidity. There is more on this at http://www.co2meter.com and http://www.co2meter.com/pages/indoor-air-quality-links.
  6. Aug 17, 2012 #5
    Here are a few things to consider: Some of your parameters, like CO2, air movement, and indoor temperature, should give a pretty good data set when monitored over a relatively short period, though long enough to include several occupied, unoccupied, and perhaps weekend type time periods. I say this because outside ambient conditions are not likely to affect these three much--the HVAC system controls the temp and air movement, and the CO2 baseline is pretty stable. (Note that the HVAC system might be programmed to save energy during unnoccupied/weekend periods, and so would automatically alter temp settings and run times--coordinate with the facilities dept. to determine that.)
    On the other hand, indoor humidity and particulates are often quite dependent on outdoor conditions, as controlling these tightly is an expensive proposition and typically only done for cleanrooms used in manufacturing of computer chips, films and emulsions, etc. So weather and wind, as well as the occupied/unoccupied cycle, will cause wide swings in these data. Particulates can also be greatly affected by routine maintenance procedures like HVAC filter changes, and even floor vacuuming. Any large 'glitches' will need to be correlated with these sorts of events. Also, the room volume will certainly have an effect on the magnitude of these variations, as will occupancy level.
    Bottom line is--analyze the reasons behind this study and the accuracy required, and also whether you have multiple pieces of test gear that can be deployed concurrently--for example temp/humidity chart recorders that can be placed in every room/area, as these are relatively inexpensive. This should give you a fair assessment of the time frame required and validity of your final results. I have done all of these sorts of measurements over the years as a facilities engineer while studying 'sick building syndrome' and the like, and I do believe you can get a pretty good data set in 60 days.
    Last edited: Aug 17, 2012
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook