CO2 and Indoor Air Quality, school me please

[Poindexter]

I have a CO2 problem. Typically my clean outdoor air carries 200-300 ppm CO2. When I am home and exhaling CO2, I need to run my HRV 40 minutes per hour. At that setting, my indoor CO2 usually runs in the 600s of CO2 ppm.

Today, with hazardous outdoor air quality I am seeing 700s ppm CO2 indoors.

Here is three pics, I'll add discussion in the next post.

 

[Poindexter]

Fundamentally, I am running everything I got at full throttle.

The sensor at "NCore" run by the EPA (and closest to my home) doesn't publish CO2. I don't know if they measure CO2.

Currently two wildfires burning within 30 miles of town. There are a couple directions the wind "could" blow from to relieve the city of wildfire smoke.

The intake filter on the HRV captures 50-100mcg/m3 of PM2.5. The box fan on the floor with one MERV 13 taped to the back draws 0.5 amps continuous. The fridge sized cabinet with 6 of MERV13 in it draws 0.6 amps continuous. My standalone dehumidifier is drawing 5.5 amps on about a 50% duty cycle to maintain 40%RH.

I could turn up the HRV to continuous to flush out more CO2, but my particle counts will start going up.

So I am looking to add some kind of CO2 capture to my IAQ suite.

 

[Poindexter]

Before you start selling me on house plants, please understand that so far this summer I have killed two dill, 2 thyme, one sage, 2 oregano and a rosemary. These were all on my kitchen counter next to my cutting board.

NASA did find that enough plants can scrub CO2 from human habitation, but they needed 10-1000 plants per square meter of floor.

https://en.wikipedia.org/wiki/NASA_Clean_Air_Study

I hear spider plants are tough and hard to kill. I will get one to see if that is true.

 

[Poindexter]

Well fiddlesticks. I have turned the HRV up to continuous.

 

[stoveliker]

I think you don't need to aim for outdoor CO2 levels indoors.

 

[Poindexter]

@stoveliker , in this thread https://www.hearth.com/talk/threads...d-indoor-air-quality-hearth-com-style.198427/ comma, I busted out my google-fu for this post: https://www.hearth.com/talk/threads...y-hearth-com-style.198427/page-2#post-2675304

In my preference less CO2 is better, some is inevitable. Given my previous findings as linked above, my comfort zone is under 700ppm. Ambient outdoor CO2 in Fairbanks, with no wildfire activity seems to run 200-300 ppm.

I think of CO2 <700ppm as the green zone. 700-800ppm, single yellow. 800-1000 ppm double yellow, over 1000ppm is the well accepted red zone.

Like PM2.5 this is an airborne pollutant I would rather keep managed in the green zone rather than try to come up with something from scratch when I am already in the red zone.

I did also have this observation in a thread about HRV systems. Running the indoor CO2 up to 1660ppm (measured) when my first CO2 detector came in the mail got my undivided attention. I had been running the HRV one hour per day as instructed by the landlord. I had been grumpy and not sleeping good and constant headaches for more than a week. Once I got the place aired out and the CO2 level under control all that cleared up save for my baseline cantankerousness.

 

[stoveliker]

Yes but all the URLs there basically say <800 is okay, recommended etc.