HK Office
8th Floor China Aerospace Centre,
143 Hoi Bun Road
Kwun Tong, Kowloon,
Hong Kong +852 2389 6502

Indoor Air Quality Monitor

A Path to Better Indoor Air Quality 

The Importance of Indoor Air Quality

We spend around 90% of our time indoors so it is important to ensure that the quality of the air we are breathing is suitable and that the air itself won't be harmful to our health. Most of our time is spent in the home or working environments such as offices where gases, chemicals, and other pollutants cause headaches, eye irritation, allergies, and fatigue.

Having an air quality monitor with audiovisual prompts - as well as the ability to notify you remotely via SMS and email when the air quality deteriorates - is hugely beneficial when it comes to managing our indoor environmental surroundings.

Temperature and Humidity

Monitoring temperature and humidity levels in your home not only helps avoid mould and mildew accumulation but also prevents allergy-like symptoms.

The EL-WEM tells you when the indoor temperature and humidity levels are not suitable so that you can act accordingly.

VOCs (Volatile Organic Compounds)

VOCs are gases emitted from a variety of common household items such as hairspray, cosmetics, cleaning fluids, disinfectants, paints, and varnishes. These gases can have short and long-term health effects. According to the Environmental Protection Agency, concentrations of many VOCs can be up to 10 times higher indoors than outdoors.

Airborne Particulate Matter

The EL-WEM measures microscopic particles that are suspended in the air such as dust, dirt, soot, and smoke.  Coarse (PM10 and PM2.5) particles can affect those with respiratory health issues such as asthma. Being able to monitor the presence of airborne particles means you can ensure the comfort and health of those within the property.


Negative indoor air pressure in summer will draw warm air in, while negative indoor air pressure in winter will draw in cold air, making your house feel drafty and increase your heating costs.

Positive indoor air pressure in summer will force cool air out, but positive indoor air pressure in winter will force warm air from inside your house out through any openings in your walls. From there it can condense and deposit moisture causing mould and wood rot deep in the structure.

IAQ Rating Index

The EL-WEM rates the Indoor Air Quality (IAQ) as one of five levels, ranging from Excellent down to Inadequate. This rating uses a points-based system, taking measurements from four parameters. The points from each parameter are added together to give the final IAQ rating. If the rating falls to Poor the sounder is activated and an email and SMS notification is sent to your selected contacts.

➤ Excellent: 18 points or more

➤ Good: 16 points or more

➤ Fair: 12 points or more

➤ Poor: 8 points or more

➤ Inadequate: less than 8 points

Featured products

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Indoor Air Quality Monitor

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WiFi Cloud-Connected Ambient Temperature Data Logger

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High-Accuracy Temperature and humidity data logger with display


stores up to 32,510 Carbon Monoxide (CO) readings


Wireless Temperature and Humidity Data Logger


Carbon Monoxide Data Logger with USB


WiFi Temperature & Humidity Data Logger

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USB Temperature Data Logger with Screen and Audible Alarm

Product Specifications

Particulate Matter Measured Categories: PM2.5, PM10

Temperature Measurement Range: -20°C to +60°C

Humidity Measurement Range: 0 to 95%RH

Humidity Measurement Accuracy: +/- 3%

Volatile Organic Compounds (VOC's) Accuracy: +/-5%

Pressure Measurement Range: 300 to 1100mbar

Pressure Measurement Accuracy: +/- 0.6mbar