Air Monitoring

Understanding Your Monitor Numbers: What PM2.5, VOCs, and CO₂ Actually Mean

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You've bought the monitor. It's showing numbers. Now what? Understanding what those readings actually mean—and what action they call for—turns a gadget into a decision-making tool.

PM2.5: The Particle Reading

PM2.5 is measured in micrograms per cubic meter (μg/m³). Here's a practical interpretation scale for indoor air:

ReadingIndoor AssessmentAction
0–5 μg/m³ExcellentYour purification is working well
5–12 μg/m³GoodAcceptable; EPA considers this "good" for 24hr average
12–35 μg/m³ModerateRun purifier on higher setting; check for infiltration
35–55 μg/m³PoorHigh setting immediately; find and address source
55+ μg/m³UnhealthyAll purifiers on max; check for infiltration event

TVOC: The Gas Reading

Total VOC readings are harder to interpret because they're sensor-relative (not calibrated to specific compounds) and different monitors use different scales. Use TVOC for trend monitoring, not absolute benchmarking.

What matters: baseline your home (readings after fresh air ventilation), then watch what causes readings to rise. Cooking? Cleaning products? Wind from the landfill direction? Pattern recognition tells you where to focus.

📊 Essential: Track Both PM2.5 + VOC

Temtop M10 Air Quality Monitor

Track PM2.5 and TVOC simultaneously. Watch trends across different wind conditions. The data you collect guides every decision.

PM2.5 + TVOCReal-Time DisplayUSB PoweredRechargeable
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CO₂: The Ventilation Indicator

CO₂ is exhaled by occupants. Outdoor air is ~420 ppm. Your home's CO₂ rises above this baseline by an amount that reflects how many people are in the space relative to ventilation rate.

CO₂ rising rapidly in a sealed room is your signal to ventilate—but check outdoor conditions first. If the landfill odor is present, wait.

🔬 Upgrade: Add CO₂ Monitoring

Temtop M10+ — CO₂ + PM2.5 + VOC

Adds CO₂ monitoring so you can balance fresh air needs against outdoor air quality. The complete picture in one device.

CO₂ SensorPM2.5 + VOC60-Day BatteryE-Ink Display
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Humidity: The Context Reading

Relative humidity affects both your health and your pollutant exposure. High humidity (above 60%) accelerates mold growth and makes some VOCs more irritating. Target 40–50% RH indoors year-round.

🌡️ All-in-One: PM2.5 + Temp + Humidity

GoveeLife Smart Air Quality Monitor

Tracks PM2.5, temperature, and humidity simultaneously. Wi-Fi data logging lets you correlate outdoor conditions with indoor readings.

PM2.5 + HumidityWi-Fi LoggingLED IndicatorApp Alerts
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Reading Patterns Over Time

A single reading tells you little. Patterns tell you everything. Watch for: PM2.5 spikes when wind shifts to the landfill direction (infiltration event), TVOC rises in early morning (temperature inversions concentrate landfill gas at ground level), CO₂ rise in closed rooms at night (ventilation deficit).

Keep a Simple Log: Once a week, note your PM2.5, TVOC, and humidity readings at the same time of day. After a month, you'll understand your home's patterns—and know exactly which conditions are your worst days.
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