AirGradient Open Air vs Apollo MSR-2 with CO2

Data from Amazon and official AirGradient and Apollo Automation sites.

2026 verdict

For this 2026 head-to-head, AirGradient Open Air has the better all-around case. It separates itself most clearly on weather resistance, connectivity, and sensors, while still looking better on alerts. Apollo MSR-2 with CO2 remains a niche alternative if price matters more than the rest of the comparison. In practical terms, AirGradient Open Air is the easier product to recommend.

Winner

AirGradient

AirGradient Open Air

$190.00

BUY NOW

Apollo Automation

Apollo MSR-2 with CO2

$56.09

BUY NOW

Feature	AirGradient Open Air	Apollo MSR-2 with CO2	Winner
Price	$190.00	$56.09	Apollo MSR-2 with CO2
Weather Resistance	YES (Outdoor)	NO	AirGradient Open Air
Connectivity	2.4 GHz Wifi, Bluetooth	2.4 GHz Wifi	AirGradient Open Air
Sensors	TVOC, PM0.3, PM1, PM2.5, PM10, CO2, NOx, Temperature, Humidity	CO2, Temperature, Atmospheric Pressure, Ambient Light, UV, Occupancy	AirGradient Open Air
Alerts	Temperature Alerts, Humidity Alerts, Air Quality Alerts	Temperature Alerts, Air Quality Alerts	AirGradient Open Air
Screen	NO	NO	Tie
Integrations	Home Assistant	Home Assistant	Tie

Winner

AirGradient

AirGradient Open Air

$190.00

BUY NOW

+ Weather Resistance: YES (Outdoor)
+ Connectivity: 2.4 GHz Wifi, Bluetooth
+ Sensors: TVOC, PM0.3, PM1, PM2.5, PM10, CO2, NOx, Temperature, Humidity
- Price: $190.00 vs $56.09

Apollo Automation

Apollo MSR-2 with CO2

$56.09

BUY NOW

+ Price: $56.09
- Weather Resistance: NO vs YES (Outdoor)
- Connectivity: 2.4 GHz Wifi vs 2.4 GHz Wifi, Bluetooth

Frequently Asked Questions (FAQ)

Which is better overall: AirGradient Open Air or Apollo MSR-2 with CO2?: AirGradient Open Air has the stronger overall profile in this comparison, especially for weather resistance, connectivity, and sensors.
What is the biggest difference between AirGradient Open Air and Apollo MSR-2 with CO2?: Price is one of the clearest differences: AirGradient Open Air lists $190.00, while Apollo MSR-2 with CO2 lists $56.09.
Which one looks better on price?: AirGradient Open Air is listed at $190.00, while Apollo MSR-2 with CO2 is listed at $56.09. Apollo MSR-2 with CO2 (better spec).
Who should buy AirGradient Open Air?: Choose AirGradient Open Air if your priority is weather resistance and connectivity and that matters more than price.
Who should buy Apollo MSR-2 with CO2?: Choose Apollo MSR-2 with CO2 if your priority is price and that matters more than weather resistance.