SwitchBot Meter Pro CO2 Monitor

Introduction

A full display for indoor and, with an external sensor, outdoor temperatures and humidity, the SwitchBot Meter Pro CO2 Monitor also tracks CO2 levels indoors to help you learn when you need to improve ventilation.

It collects hugely detailed reports in the app, although I found it best at showing me what the actual conditions outside are like. A few clunky parts of the interface get in the way, but this is a cheap and reliable weather station.

Design

• Desktop or wall mounted
• Can be USB-C powered
• Has two AA batteries

A simple device, the SwitchBot Meter Pro CO2 Monitor is designed with an always-on screen to show you current conditions at one location. That screen’s not backlit, so you can happily put the monitor anywhere and it won’t disturb you at night. It’s a touch plasticy, and lacks a premium feel that you might expect at this price.

There’s a choice with this device to mount it on a desk or shelf, using the fold-out stand, or to wall mount it using the eyelet at the back. I prefer the latter option, as it keeps the device out of the way, but it’s nice to have the flexibility.

There’s also a choice of power options. For permanent power, a USB-C cable is included in the box. This cable is a flat ribbon, so it fits into the cut-out in the rear, whether you use the SwitchBot Meter Pro CO2 Monitor in desktop or wall-mounted modes.

Alternatively, the SwitchBot Meter Pro CO2 Monitor can be powered by two AA batteries, allowing you to place the device anywhere you want.

There’s no need to buy anything else for this device, and you can connect to it via Bluetooth using the app; however, if you want the weather forecast feature to work and remote control, you’ll need to have a compatible SwitchBot Hub within Bluetooth range.

Features and Performance

• Needs an external sensor for outdoor temperatures
• Single button on top doesn’t do much
• Detailed logging in app

In its default state, the SwitchBot Meter Pro CO2 Monitor uses its onboard sensors to present information about the internal environment. These include the CO2 level in parts per million (PPM), provided by a NDIR Swiss Sensor, which is accurate within +/-50ppm. There’s also a temperature sensor and a hygrometer for humidity.

To give you an idea of whether the current conditions are good or not, there’s a bar at the top split into green, amber and red portions, from good to bad CO2 conditions. As CO2 concentrations rise, you can feel tired or get a headache, so the indicator is a good way to show when it’s time to ventilate the room.

There’s a second bar at the bottom, which works differently. If the temperature and humidity conditions are ideal, then it points to Comfort; regardless of temperature, if the humidity is low the bar shows Dry; if humidity is high, the bar shows Wet.

Confusingly, if humidity is at the right level but it’s too hot or too warm, the indicator completely disappears.

By default, the SwitchBot Meter Pro CO2 Monitor is set for ‘human’ comfort levels, which are temperature between 18°C and 28°C and humidity between 30% and 70%. However, you can override these settings with your own.

If you connect the SwitchBot Meter Pro CO2 Monitor to a Bridge, it will show a live weather forecast in pictorial form, such as a picture of a sun, clouds or rain clouds. Just make sure that you’ve set your address properly in the app.

To save on battery life, the weather forecast is only updated twice a day, once at midnight and once at midday. That’s fine for a lot of areas, but if you live somewhere with very changeable weather (Cornwall, I’m looking at you), then it would be better if updates could be set to be more often.

It should technically be possible, as the temperature update can be changed (default is every 10 minutes), as can the CO2 update (every 30 minutes by default). Oddly, the screen shows the time in minutes since the last CO2 update, but not since the last temperature update.

While the CO2 level is interesting, the indoor temperature and humidty levels are generally something that you get from other smart devices. In my house, my Tado X system tells me everything about each room.

More usefully, the SwitchBot Meter Pro CO2 Monitor can be paired with an Indoor/Outdoor Thermo-Hygrometer, which is available separately. I like to see the actual outdoor temperature where I live, as it’s a more accurate way to see what I should wear or whether it’s nice enough to go and sit in the garden.

Once you change the data source, the screen will show the outdoor temperature and humidity, but keeps the CO2 reading as internal.

To make things less confusing, there’s an option to change the panel so that it displays an ‘outdoor’ sign, rather than ‘indoor’.

I’d like to be able to switch between indoor and outdoor temperatures at the touch of a button, but this isn’t an option. There is a button on top, but this only has two options: refresh data, or refresh data and change between °C and °F.

Using the app you can see a whole lot more data, and the system logs everything. Just note that the temperature and humidty readings you see in the app are from the internal sensor; to view external data you need to view the wireless sensor separately.

There are also readings for Absolute Humidity, which tells you how much water is actually in the air in g/m³; the Dew Point, which changes with humidity levels and temperature; and Vapor-pressure Deficit, which tells you how much water is in the air vs how much water the air can hold. That’s a lot of information, but it’s probably of limit use to the masses.

Matter support via a Hub is supported, so I connected the SwitchBot Meter Pro CO2 Monitor to Apple Home. Here, I got temperature and humidity readings but that was it.

It’s not particularly useful using Alexa, either. Asking what the carbon dioxide level is to get a numerical reading is of limited use.

Should you buy it?

FAQs