Page 3 of 3 FirstFirst 123
Results 27 to 39 of 39
  1. #27
    Join Date
    Mar 2005
    Posts
    997
    Post Likes
    Again check the co2! This will tell you how much outside air you are getting!

  2. #28
    Join Date
    Aug 2006
    Location
    Canada
    Posts
    8
    Post Likes
    A three year old house is pretty new. New homes are built tighter than ye' old days. Newer homes are built with composite materials such as particle board that emit VOCs, and larger amounts when the material is humid. When you come home after being away for a few days do you get hit with that "new house" smell? This would be the off-gassing construction materials including kitchen cupboards, flooring material, carpets, furniture etc.
    The HRV was a good addition. By constantly bringing in fresh air it will dilute the pollutants. However if the HRV (or your furnace) return air is routed using floor joists as make-shift plenums, again constructed of off-gassing construction materials, you may be distributing more VOCs and that may explain the spikes, coincident with the furnace fan cycling.

  3. #29
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    9,702
    Post Likes
    Quote Originally Posted by tfwalsh View Post
    The negative pressure idea is very interesting. It would explain why things are worse in the winter. If this is the problem, is there a way to fix it? If it is sewer gas, how can we stop it from coming in? We already have a Lennox Heat-recovery ventilator installed, and I thought that was supposed to create a positive pressure in the house.
    Clothes drier, kitchen hood, bathfans, and stack effect cause negative pressure at the lowest levels in the home. Wind is the biggest negative pressure generator. HRVs are balanced flow devices at best. Most are installed poorly. Balancing the in/out flow and distribution are issues most contractors do not deal with.
    The most effective ventilation is make-up air distributed low in the structure. Most air leaves your home high in the structure and down wind. The idea of low water in traps, marginal vent stacks, and burping when flushing toilets also allows soil gases to enter the home. Keep in mind stack effect is at it's high middle of the night.
    More make-up air ventilation and tape the drains that are not used regularly. Maybe block the inlet of HRV and operate the make-up air on high speed. High vocs should be able to be identified with air sampling by a good industrial hygienest. If high vocs are and occasional-why worry. Most people are leaving in under ventilated homes epesially during the summer a/c season because of the lack of stack effect. More proof is that any home in a green grass climate geting an air change every 3 hours requires mechanical ventilation. Also they would get damp after an evening of 3 air changes. ---Unless they have supplemental dehumidification. Regards TB
    Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
    Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
    Use +Merv 10 air filter. -Don't forget the "Golden Rule"

  4. #30
    Join Date
    Aug 2006
    Location
    Canada
    Posts
    8
    Post Likes
    If it were sewer gasses causing a VOC measurement device to show readings off the charts, I would think that the house might have a sewer gas smell. Probably not the cause...

  5. #31
    Join Date
    Mar 2005
    Posts
    997
    Post Likes
    Why doesn't your IAQ company test for methane! If they think it is sewer gas. Plus with out a carbon dioxide reading, you have no idea how much fresh air you are getting This should be a baseline test and should be with the first test you would take!!!

  6. #32
    Join Date
    Mar 2007
    Location
    Myrtle Beach, SC
    Posts
    2,970
    Post Likes
    Quote Originally Posted by pmeunier View Post
    Is the Airadvice sensitive to "digestive emissions"? The Oregon Scientific "air quality monitor" is quite sensitive to them. It's not necessarily bathroom sessions; perhaps one of the water traps in your plumbing system has become dry (e.g., basement) and you're getting sewer gas in the house.
    I have bought stuff from Oregan Scientific. I have never seen an "Air Quality Monitor" listed. Do you have a model number? TIA.
    Remember, Air Conditioning begins with AIR.

  7. #33
    Join Date
    Aug 2003
    Posts
    907
    Post Likes
    Quote Originally Posted by Kevin O'Neill View Post
    I have bought stuff from Oregan Scientific. I have never seen an "Air Quality Monitor" listed. Do you have a model number? TIA.
    ar112, not available anymore, probably didn't sell well.

    http://www.amazon.com/Oregon-Scienti.../dp/B00006J047
    Availability: Currently unavailable. We don't know when or if this item will be back in stock.

  8. #34
    Join Date
    Jan 2008
    Location
    Cincinnati Oh
    Posts
    3
    Post Likes
    You say that the monitor spikes on vocs at different times at those times what are the humidity readings and the temperatures. Are they different than others. It has been my experience that voc presence will rise if the humidity is too low,and that may be the reason they are more acceptable in the summer when the humidity is higher. However the chemicals in your home such as paints and glues will off gas for 7 years. Check the low humidity. 40 to 50% is a good range.

  9. #35
    Join Date
    Jan 2019
    Posts
    39
    Post Likes
    Did you ever discover the culprit of the sporadically high VOCs?

    We have this EXACT problem. We all wake-up ill nearly every night... Is been 4 months since we moved in: Our airthings monitor shows crazy VOC spikes. Always, and only, at night.

    Was it the negative pressure? Or stuff coming from the furnace? If you found any answers, it would be a huge help to us!

  10. #36
    Join Date
    Dec 2015
    Location
    Austin
    Posts
    121
    Post Likes
    Quote Originally Posted by tfwalsh View Post
    Hi,

    We recently had an AirAdvice installed to measure the air quality in our house. Everything was good (particulate levels, carbon monoxide, humidity, etc) except for the VOC's, which are through the roof. They averaged around 3000. We then had a PureAir filter installed, which is supposed to reduce VOC levels by 50%. It did not help much. Then, we had a ventilator installed, which continuously brings fresh air into the house and removes stale air from the house. That helped a little, but we still get these spikes that go over 3000. The ventiltor then seems to work a little, in that it starts bringing the levels back down, but then they spike to 3000 again.

    These spikes are not from cleaning, etc., since many of them happen at night when we are sleeping, and some have happened when we were out of the house.

    Any ideas on what could be causing these spikes? Could it be our HVAC system?
    I'd be very skeptical of readings on the AirAdvice unit. They use a Honeywell ppbRAE3000 to calibrate at their shop and calibration, even on a ppBRAE3000 is touchy. Much less 1 step removed on the Air Advice. I speaking from direct experience with the ppBRAE3000. I've used this device many times for testing I've done

    Also do you know if the *3000* reading is in ppb or ug/m^3. If it's in ppb the readings are exceptionally high and I would suspect you would smell something. If the readings are in ug/m^3 the readings are still high but not as bad.

    Also if the AirAdvice is not using PID technology it's next to useless.

    If you can take the AirAdvice outside. Readings should be very, very low - close to zero. If anyone tells you differently - they don't know what they are talking about (assuming you don't live under a freeway or next door to a unregulated chemical refinery or in S. Cal in the summer when ozone levels are very high). If readings are high outside the Air Advice is unreliable. Indoor VOCs are generated by what's indoors not outside. Particulate pollution is just the opposite.

    Here a couple of suggestions to get accurate VOC readings:
    1. Check out Home Air Check -https://homeaircheck.com/products/
    For about $150.00 - 210 they will provide a test kit to take a calibrated sample your air. The sample is returned to Prism Labs and tested via Gas Chromatography/Mass Spectrometry. This is the gold standard for VOC testing.

    Another provider is: : www.fikeanalytical.com. Fike is more expensive, but probably more accurate. One advantage of using Fike is that it includes a discussion with a PHD analytical chemist.

    2. You can rent a real calibarted PID meter from Pine Environmental: http://www.pine-environmental.com/. They've got about 30 locations in the US. Price is about 150.00 for the weekend. This would immediately indicate if the Air Advice is misreading. If you do rent from Pine send me a PM for some tips on proper calibration before accepting the device.

    My recommendation would be (1). This would provide the most accurate info. Also GC/MS testing indicates what types of VOC are detected. PID meters only indicate Total VOC levels without regard to type of VOCs. Also PID meters can not detect many VOC that GC/MS can.

    If you do any of the test above and find a discrepancy with the Air Advice - I'd get my money back.

    Here's a link to a pdf on the basics of VOCs, measurement and abatement:
    https://www.dropbox.com/s/i6eor9zfh0...n%206.pdf?dl=0

    Good Luck and I'd be very interested on what you find.

  11. #37
    Join Date
    Dec 2015
    Location
    Austin
    Posts
    121
    Post Likes
    Sorry, my bad. Just discovered this post originated in 08.
    In any case - the info in my post still applies to your query.

    If you're using one of the recently available consumer air monitor i'd be suspicious.
    Check out HomeAirCheck. You might also want to see if your particulates high. See Dylos - http://www.dylosproducts.com/

  12. #38
    Join Date
    Feb 2009
    Location
    Home Energy Products: 170 DW Hwy, Belmont, NH 03220
    Posts
    56
    Post Likes
    I hope we get a root cause on the complaint this time. I'm darn curious.

  13. #39
    Join Date
    Apr 2003
    Location
    St. Louis
    Posts
    1,269
    Post Likes
    Would like to see what a ozone generator would do for your voc but wouldn't use one in a condo being afraid of ozone transfered to your neighbor. Built one with two plates from ebay and other parts put it in my crawl space and within 20 minutes could feel the o3. But with a sealed house and running it for 2 hours or overnight then ventilating the house then vacuum.Wondered if that would knock down the voc.

Page 3 of 3 FirstFirst 123

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •