I posted this elsewhere a few days ago so I'll just copy it here. It's pretty much self-explanatory but there are a few comments to link it into the thread. I have the 0.5/5 micron unit with computer port.
You won't see any furnace cycling in the house measurements. My furnace has a two-speed fan and runs continuously all year long. I have an electronic air cleaner on the cold air return to the furnace with a reusable electrostatic filter in front for a prefilter.
You will see reinforcement of the impact in the house of showers, cooking and opening the door and allowing infiltration of outside air.
You will see reinforcment of the increase in fine particle counts due to RH from a weather system moving in overnight.
You will also see reinforcement that even a small dust collector with a decent filter on it acts as a passable air cleaner. I have a cheap 1HP King with a 1 micron upper bag and clear plastic lower bag. It pulls the fine particle count down nicely when it's running. Even my 2 1/2" shop vacuum with HEPA filter in it will pull the count down a little as long as the exhause isn't pointed at a dust pile.
It's still too cold here on the Canadian prairies (great plains) to do outdoor readings for correlation purposes.
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Okay, I finally got around to cleaning up the spreadsheets and grabbing the charts. I have a couple from the living room and a couple from the shop.
The first is 24 hours from the living room, starting monitoring at 8:12am.
The early spikes between 1 and 658 are mainly from the front door opening. The one at 74 is someone taking a shower.
The big jump at 658 was preparing supper. There was a break in the reading while I saved the data and fiddled with the spreadsheet for a few minutes at the point where it drops way back just after 804. I'm not sure why the straight drop instead of a gradual decline.
The gradual increase, starting at 1023 is overnight. The only explanation I can think of is that a serious weather system moved in overnight. The spike at 1461 was leaving the house to head for the gym (front door opening). The final spike at 1534 was from taking a shower.
Here is another 12 hours from the living room, starting monitoring at 10:50am.
This one looks much smoother than it really was. That huge spike at 417 was sauteeing onions in the frying pan at supper time. It spiked so high (over 8800) that the scaling on the chart makes the rest of the readings look much smoother than they really were. If I chopped that part of the chart off, you would see bumps throughout the day from the front door opening, showers and other typical daytime activities.
One of the things that would show up much more significantly is when I came in from the shop (235 to 270) and sat in a chair near the unit. It's surprising how much dust comes back in on your clothes and hair, and also how long it persists. I sat near the unit for nearly an hour and the reading stayed up. It didn't start to drop back down until I left the room.
Here is approx. 8 hours in the shop, starting at 4:35pm.
I entered the shop and puttered for a few minutes. Fired up the big shop vacuum and cleaned up a bit around the lathe. Then I ran a 10' flex hose extension over to the lathe. I turned on the dust collector at 30. You see the spike and then a steady decline. During that decline I was turning a couple of small spindle items, including some sanding.
The bump in the downslope at 65 was a quick cut on the mitre saw. I turned the dust collector off and left the shop at the 135 mark. The rest was reading in the empty shop. You can see two distinctly different trend lines. In the small particle chart you can see the reading climb. I assume that's the fine dust starting to settle closer to the meter. If I had been sitting in the shop I'm sure I would also be able to identify bumps from the construction heater going on and off.
The trend on the large particle chart is a steady decline. I assume that's also settling, in this case onto flat surfaces where they stay and are not disturbed by the heater fan.
Finally, another 4 hours in the shop, starting at 1:52pm.
You can see a bit of a drop in the small particles when I turned the dust collector on at 10. The spike at 15 is a quick cut on the mitre saw followed by rounding off a small bowl blank on the bandsaw. I was turning the small bowl blank then I stopped, turned the dust collector off and left the shop at 109. I came back into the shop at 220 and turned the dust collector on for a few minutes just to see what would happen. Finally I turned the dust collector off and stopped monitoring.
It has mostly been too cold to do any baseline readings outside. The documentation with the meter warns against running it when it's too cold so I haven't.
...ken...
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Originally Posted by Greg Funk
