Quote:
Originally Posted by theworldtrekker
What I see however, is a variety of different rates and unexplained drops.
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I think that people assume that I live like they live. I don't.
I am only conditioning one room.
As I said previously, it is not a large room.
The kitchen is not heated and not conditioned and not subject to CO2 monitoring.
The bathroom is not heated and not conditioned and not subject to CO2 monitoring.
The room I sleep in is not heated and not conditioned and not subject to CO2 monitoring.
The big drop was because I left my house to run some errands. There was no one home to generate CO2. The CO2 started climbing higher when I returned... The smaller drop was when I went next door to visit a neighbor. CO2 climbed much higher when a friend dropped by.
I was pretty sure that I had explained all that before.
Quote:
Originally Posted by theworldtrekker
Why, if you were in the house all night do you start out at ~440ppm yet end the day at 1050ppm?
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See above... ("...not heated and not conditioned and not subject to CO2 monitoring...")
Quote:
Originally Posted by theworldtrekker
Why is the rate increase different between data point 2-3 and 5-6 vs 3-5 and 6-9? Why the drastic drop while you're gone until 1330, but not the same slope of drop when you go to the neighbor with soup? And finally, why when there are two people in the house is the slope of increase less than between data points 2-3 and 5-6 but the same as when you got back at 1300 until 1930?
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I'm logging by hand, I log when I'm home.
Quote:
Originally Posted by theworldtrekker
Here are a few hypothesizes that come to mind:
1) You're measuring CO2, but CO2 in your house isn't driven by human sources. Instead it is driven by construction materials still curing. I know this plagued Biosphere II for a number of years with curing concrete (if my memory serves me).
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In the space that is conditioned, my construction materials have been curing for 32 years. Would that be long enough?
Quote:
Originally Posted by theworldtrekker
2) You're sensor is temperature dependent.
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Its optical in nature and either the LED or more likely the sensing cell is temperature dependent. You've ruled out humidity it sounds like, but I would have guessed temperature is more likely to dominate anyway. Could also be some other factor that is affecting the sensor (supply voltage, saturation, location, etc). [/QUOTE]
Nope, it's been 67 degrees all the time... dead on.
Quote:
Originally Posted by theworldtrekker
Need more data points... Its not too hard to hook up a SD card to an arduino (SPI interface) and have it log every ~5 min. Either buy a SD shield or OSH Park ~ Welcome (from dorkbotpdx)has a nice cheap PCB service 'local' to us. |
Great! I have an Arduino, I have an Ethernet shield, write me the code and I'll run it.
Quote:
Originally Posted by theworldtrekker
I would guess, as stevehull pointed out and I've observed in my house, that humidity will be a greater issue than CO2. So even with a CO2 sensor feed on the controller, you'll also want a humidity sensor feed as well. I'd worry more about the logic of the two combined sensors than trying to accurately track one value. If the house and sensors don't dampen the system enough, it'd be pretty easy to program some basic dampening logic into the fan controller.
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I tracked humidity all day, and it has been within 1% of 43% all day.
Have you ever measured the CO2 of the space you live in, by any chance?
-AC