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  1. #40
    Join Date
    Aug 2004
    Location
    North Richland Hills, Texas
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    Quote Originally Posted by tagb0000 View Post
    Today's Blower Door Test results: 3300 CFM @ 50 Pa.

    Test was done at single exterior door. The independent assessor did not believe doing a test at the third floor (attic) area would give any usable data. Further, he estimates there are about four (4) air changes per hour.
    The 4 ACH number is not remotely consistent with the 3300 cfm50 test result.
    In your size house, 3300 cfm50 would likely equate to less than 1 ACH under natural conditions, as long as the still existing PAV is not running.
    When that PAV runs, it likely jacks your ACH up quite a bit.

    The foam installer doesn't seem to have a clue as to where the foam should be sprayed.

    You have a rather schizophrenic building envelope...
    If you are going to spend the large sum of money to foam the under side of the roof, the effort needs to be made, and verified via blower door testing to completely seal the attic, making everything under it part of the conditioned space.
    With a properly sealed attic, there really isn't any point to spraying foam on the knee walls, it is just a waste of very expensive foam.

    All of the vented combustion appliances will also need to have their own source of combustion air piped to them.
    This can either be accomplished by building an insulated mechanical room around them, that has combustion air ducted into it, or by replacing them with sealed combustion appliances.

  2. #41
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
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    9,765
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    Quote Originally Posted by tagb0000 View Post
    I truly appreciate the knowledge about missed opportunities. This will be helpful if/when we build another house. Meanwhile, we still seek strategies to correct or compensate the current conditions.

    Early in this thread Teddy Bear wanted to know CO2 levels along with temp and RH. A glitch in the meter caused the loss of a several day’s worth of data. Without further ado, here is the graph. Raw data is available for anyone who requests it. Sample rate was one minute, temp, RH and CO2. The next sampling will be a longer rate, such as every ten minutes. I am open for suggestions for different sample rates.

    Data was collected over a five day period, on first floor, near center of home, a few feet from thermostat.

    Highlights of the captured data, (highest/lowest):
    Temp: 74.2/68.7
    CO2: 669/404
    RH: 35/22.1

    Attachment 470851
    My internet was down for a couple days, sorry.

    Looks like you outside is about 400 to 450 ppm CO2 because that is the lowest readings when the home is not occupied. Getting up to 550 suggest you are getting 50 cfm of fresh air when the home is occupied. If you have 2 occupants, you getting about 100 cfm of fresh air infiltrating the home. This is a minimal amount for a home your size. 150 cfm of fresh air would be ideal.
    I would expect more infiltration during colder or winder weather. Like wise, less fresh air infiltration during calm warmer weather.
    How many occupants do you have at the stable higher CO2 levels? Is the home unoccupied during the lower levels? Also open a couple doors in the house to obtain outside CO2 levels.
    Keep us posted. I am willing to review the data if you email it to me. Big homes getting enough fresh air during low outside dew points with only a couple occupants need humidifiers. They also need dehumidifiers during high outdoor dew points and low/no cooling loads.
    Post more graphs.

    Regards TB
    Data collection at 10 mins. intervals is just fine.
    Ne
    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"

  3. #42
    Join Date
    Jan 2014
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    16
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    Thread Starter
    Quote Originally Posted by teddy bear View Post
    Looks like you outside is about 400 to 450 ppm CO2 because that is the lowest readings when the home is not occupied. Getting up to 550 suggest you are getting 50 cfm of fresh air when the home is occupied. If you have 2 occupants, you getting about 100 cfm of fresh air infiltrating the home. This is a minimal amount for a home your size. 150 cfm of fresh air would be ideal.
    I would expect more infiltration during colder or winder weather. Like wise, less fresh air infiltration during calm warmer weather.
    How many occupants do you have at the stable higher CO2 levels? Is the home unoccupied during the lower levels? Also open a couple doors in the house to obtain outside CO2 levels.
    Keep us posted. I am willing to review the data if you email it to me. Big homes getting enough fresh air during low outside dew points with only a couple occupants need humidifiers. They also need dehumidifiers during high outdoor dew points and low/no cooling loads.
    Post more graphs.

    Regards TB
    Data collection at 10 mins. intervals is just fine.

    Thanks for the information and offer for continued help. Clearly, my deal with the foam installer was not pristine. (I know, understatement of the year.) Meanwhile, I am trying to salvage what I can of the situation.

    I have been in New York City at a client site, therefore, I have not been tending to my home as much as necessary. However, the CO2 meter has been recording, and I have posted a graph of March (March 9th through April 6th anyway). Through out the posted recording time, the house was occupied by at least one person. As a general rule, our house is occupied by one or two people all day every day. [This is kind of sad when I type it.] This month's graph will be different due to my travel. Also, given the outside temperature is going up, we will soon know if the indoor RH is going to follow the outside RH.

    The first weekend of March four family members stayed with us over the weekend. Sunday morning the CO2 meter started alarming (it was set to factory defaults). CO2 levels were <1000 PPM. While shutting off the alarm, I somehow lost the data. My brother-in-law commented that everyone needed to stop talking (we both agreed on that statement). My point is, that the CO2 level went up sharply when the occupant level increased (from 2 to 6). The meter was in an open room, adjacent to the room where everyone was waiting on breakfast - and apparently jawing too much.

    Name:  TIM12_March.jpg
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  4. #43
    Join Date
    Jul 2008
    Location
    Rochester NY
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    PAV possibly causing depressurization danger, some thermal boundary confusion, two ND water heaters, non sealed combustion furnaces, major humidity issues, and apparently no qualified local help.

    Hmmmm.


    Fly erla or tips in to pm this. Some process thoughts:

    In your climate the ventilating dehumidifier will be a wise investment no matter how much further you go fixing this house. Get fresh air and some dehumidification control.

    Next I'd consider sealed combustion or better, electric (or hp) water heater(s).
    Next I'd consider multi stage heat pumps. Size aggressively small. Smaller is better.
    Now you can fix the holes erla mentioned, and the holes that were required by the crappy equipment you replaced.
    ​Energy Smart Home Performance client process -
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  5. #44
    Join Date
    Nov 2004
    Location
    SW FL
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    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  6. #45
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
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    Good graph. Talking does not raise the CO2 levels. It is breathing that causes CO2 to rise. So, stop breathing.
    Keep tracking. The amount of air change changes with wind and inside temp vs. outside temp. Track outside dew point verses inside dew point verses the number of occupants. No occupants = inside and outside dew point will equalize. As the number of outside occupants increase, the inside dew point will rise above outside dew point. With a very small amount of air change, the inside dew point will be much higher than the outside dew point. You see the effect wind and stack on the house.
    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"

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