Anybody monitor their home oxygen levels?

softdownsoftdown Solar Expert Posts: 3,494 ✭✭✭✭
Figuring that the off grid solar crowd may tend to build air tight energy efficient structures to reduce their needs for heating and cooling.

Had thought that my own needs for "fresh air" would be reduced with a 400 sq ft bedroom adjoining an equally sized sunroom. Well it turns out that oxygen levels go from 20.9 (normal) to 20.5 pretty easily. That happened in four hours - without a heater being on. Plus the replacement doggie door doesn't have a good seal - it is just a rubber flap covering most of the doggie door hole. Max is an energetic one dog demolition machine. So much fun and so expensive.

Gave the door a 4" gap and oxygen went back up to 20.9. Closed the door and oxygen fell to 20.5. Opened the door 4" and oxygen remains at 20.5 with a heater running. 

My Macurco oxygen meter sounds an alarm at 19.5 percent oxygen levels. Now I expect to hear that once or twice. Humans can normally live down to "~13% oxygen levels".  I might imagine that "guideline" is also determined by altitude. 

FWIW - portable oxygen meters costs about $115 and up. They last for two years. Some have rechargeable batteries but it seems that sensors only last about two years. Macurco's, for example, are solidly built in S Dakota and costs about $140. 

Miners often wear such meters for oxygen levels and hydrogen sulfide levels. Hydrogen sulfide is possibly rare but can be lethal.
First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries

Comments

  • jonrjonr Solar Expert Posts: 1,384 ✭✭✭✭
    Any tightly sealed space needs an ERV or HRV to bring in fresh air.   More people monitor CO2, but it's also about other pollutants.

    I am available for custom hardware/firmware development

  • softdownsoftdown Solar Expert Posts: 3,494 ✭✭✭✭
    Indoor O2 levels are now 20.5 while outdoor is 20.9. I leave a window open during the day. Guessing I'm not going to worry unless 02 drops some more. Not much difference between 20.9 and 20.5 - which may be ~20.72. The meter rounds out readings to ".5".

    I have CO2 alarms. But one has to simply trust that they work. I like to have a digital readout. 

    Also think they all quit in a couple years due to limited lifespan of the sensors. 

    At close to 8000' altitude, I lose a lot more 02 due to elevation than to the current indoor variance.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • mike95490mike95490 Solar Expert Posts: 9,091 ✭✭✭✭✭
    I can't even begin to imagine how you can construct a dwelling that is so airtight (sick house syndrome), you can actually drop O2 levels in it.  A couple of % could very well be meter variation over time. 
    In order to avoid constant testing expenses, use engineering principals to allow enough passive air exchange to prevent meaningful O2 reduction. 
    And you have to remember there is % and there is O2 pressure.  You could have 100% O2 @ 0.5psi, and be in serious trouble.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
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  • mcgivormcgivor Solar Expert Posts: 3,602 ✭✭✭✭✭✭
    Heat recovery ventilators, HRV, are commonly used in airtight structures especially in the case where they have a high occupancy, such as portable buildings used as classrooms where there is lack of makeup air, the air to air type are pretty efficient and make a substantial difference in air quality. Then again with a low occupancy its probably easier to allow an air change once in a while, certainly less expensive.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
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  • softdownsoftdown Solar Expert Posts: 3,494 ✭✭✭✭
    I get an 02 meter and now feel like I should get a Masters degree in home air circulation. Must be at solar-electric.com.  :)


    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
     worked in a building from ~1982 to 1987 that was built in ~1980-1982.....  It was a brand new design and Completely Sealed according to the engineers BUT that was  more true than they knew...  after about 6 months, those people that had respiratory issues started complaining of severe headaches that would set in by morning coffee time and would not stop till a few hours after leaving the building... Plans were reviewed and a complete cleansing of all the blowers and air ducts, etc... no change...  then they noted that the 'make-up air' % was a bit low.....  after much searching they found that some  i****  brick-layer had closed in the opening destined for the Ventilation Air Vent !  The only fresh air  was coming in the exterior doors when people entered the office....  I will never work or live in a 'sealed building' again..  If you are concerned open a window or 2...
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
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    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • softdownsoftdown Solar Expert Posts: 3,494 ✭✭✭✭
    ^^We built a custom home for/with our parents and did a good job sealing and insulating. So good that mom always left the bathroom window open several inches during the winter, much to dads consternation. I don't think sealing a cold weather home is always totally productive.

    Nonetheless, I went ahead and sealed this place pretty well while fantasizing about energy efficiency. Last night the O2 dipped to 20 from 20.5 while outside air is 20.9. That concerned me a bit since no heater was on. Then I got  beeps twice later on. When those things waken you there is no way to know if it is just a low battery in a smoke alarm. Or maybe it is the carbon monoxide detector? The second beep made it hard to sleep. In a groggy state I couldn't find the offending smoke alarm. Or whatever it was. I love gadgets, there are many battery operated devices around.

    Now I am pretty sure that low O2 levels are possible without more ventilation. Have not even started using a heater until awakening. 

    Feeling good about the investment in the quality O2 meter though. O2 issues may be more common than we know. Which would go over like a lead balloon while "they" are preaching to us about our carbon footprint. Imagine if everyone started opening windows during the winter. Heating bills could double.

    Guess Max possibly did me a favor when he blew out the doggie door that had a magnetic seal.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • softdownsoftdown Solar Expert Posts: 3,494 ✭✭✭✭
    Thinking it was possibly the O2 monitor that goes off at 19.5% since I did see 20% around midnight. I've always used a lot of O2 - a weird amount for a healthy guy.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • bill von novakbill von novak Solar Expert Posts: 891 ✭✭✭✭
    softdown said:
    Figuring that the off grid solar crowd may tend to build air tight energy efficient structures to reduce their needs for heating and cooling.

    Had thought that my own needs for "fresh air" would be reduced with a 400 sq ft bedroom adjoining an equally sized sunroom. Well it turns out that oxygen levels go from 20.9 (normal) to 20.5 pretty easily. 
    That's nothing; similar to driving someplace 500 feet higher.  (When I bike to work, my elevation changes 400 feet along the way, and it's really not noticeable.)

    The bigger problem is increase in CO2 in enclosed spaces, since people generate it, and we are sensitive to lower concentrations.  An increase from .04% (normal concentration*) to .1% can cause noticeable drowsiness, and .2% can cause headaches and restlessness while sleeping.  So a change of just .06% of CO2 is noticeable, whereas a change of .4% of oxygen generally isn't (at least for a healthy person.)

    (* - it should also be noted that that is rising steadily, so in the future it won't take as much trapping of CO2 to cause air quality issues.)
  • softdownsoftdown Solar Expert Posts: 3,494 ✭✭✭✭
    edited October 2018 #11
    softdown said:
    Figuring that the off grid solar crowd may tend to build air tight energy efficient structures to reduce their needs for heating and cooling.

    Had thought that my own needs for "fresh air" would be reduced with a 400 sq ft bedroom adjoining an equally sized sunroom. Well it turns out that oxygen levels go from 20.9 (normal) to 20.5 pretty easily. 
    That's nothing; similar to driving someplace 500 feet higher.  (When I bike to work, my elevation changes 400 feet along the way, and it's really not noticeable.)

    The bigger problem is increase in CO2 in enclosed spaces, since people generate it, and we are sensitive to lower concentrations.  An increase from .04% (normal concentration*) to .1% can cause noticeable drowsiness, and .2% can cause headaches and restlessness while sleeping.  So a change of just .06% of CO2 is noticeable, whereas a change of .4% of oxygen generally isn't (at least for a healthy person.)

    (* - it should also be noted that that is rising steadily, so in the future it won't take as much trapping of CO2 to cause air quality issues.)

    CO2 is carbon dioxide. Yet a search for CO2 meters always yields carbon monoxide alarms and meters. We all know that carbon monoxide is lethal. Generally a product of inefficient combustion like a defective propane heater or most any internal combustion engine such as a generator or auto engine. I knew someone who died in her garage while her Cadillac was idling away. 

    We should all have carbon monoxide and smoke alarms as a bare minimum.

    My O2 level is currently down to 20.0 with a small heater on. I suspect it may dip lower as winter weather marches forward. Losing 10% of O2 concentration at 8000' may start to approach significance for some.

    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • Ralph DayRalph Day Solar Expert Posts: 927 ✭✭✭✭
    I've got an always on battery box fan, sometimes range hood, sometimes bathroom fans, propane range and water heater to contend with..plus the wood heat in winter.  There's a 3" dryer vent open year round (screened for bugs), and in the winter I open a basement window a bit in the basement where the wood stove is.  No idea about O2 levels, but not stuffy (since I started opening the window too).  Healthier sinuses, less colds...but that might be because I stopped driving a school bus.  As I called it "the big yellow incubator".

    Ralph
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