TL;DR: The $16 HOMEFISH CO2 monitor effectively solved work-from-home brain fog by identifying high CO2 levels - buy recommended for WFH workers.
What are the key specs?
| Feature | Details |
|---|---|
| Measurements | CO2, Temperature, Humidity, TVOC, HCHO |
| Discount | 52% off |
| Original price | $32.97 |
| Sale price | $15.83 |
| Units sold | 4,001+ |
| Rating | 84.7% positive |
| Store | HOMEFISH Direct Store |
Five measurements in one compact device — CO2, temp, humidity, TVOC (volatile organic compounds), and HCHO (formaldehyde).
Why was I getting afternoon brain fog at home?
Ever since I started working from home full-time, I noticed I'd hit a wall around 2 PM every single day — headaches, drowsiness, total lack of focus. I read that CO2 levels above 1000ppm can seriously tank your concentration, and since I work in a small room with the door closed, that seemed like the likely culprit. Professional CO2 monitors run $50-100+, so when I spotted this HOMEFISH 5-in-1 monitor on AliExpress at 52% off for just $15.83, I figured it was worth a shot.
How was the delivery and unboxing experience?
It arrived in about 12 days, well-packed in bubble wrap. The unit itself is slightly larger than a deck of cards — compact enough for any desk. The color LCD screen is surprisingly crisp and easy to read at a glance. It powers on via USB-C and has a built-in battery so you can move it between rooms. After turning it on, it takes about 30 seconds to warm up before readings start appearing.
How does it perform in real use?
Here's where it gets interesting. I closed my office door and worked for two hours. The CO2 reading climbed steadily to 1,400ppm. Opened the window for 10 minutes, and it dropped back to around 600ppm. Being able to see this in real time completely changed my ventilation habits. I also tested it near new furniture, and the TVOC readings were noticeably higher there. Temperature and humidity were within 1~2°C and 3~5% of my dedicated hygrometer — close enough for practical use.
How does the price compare to alternatives?
| Store | Price |
|---|---|
| AliExpress (sale) | $15.83 |
| AliExpress (original) | $32.97 |
| Coupang (similar) | $25~50 |
| Naver Shopping (similar) | $22~42 |
For a 5-in-1 air quality monitor, the AliExpress sale price is hard to beat.
Pros and cons
Pros
- Measures 5 air quality metrics simultaneously
- Clear color LCD display
- USB-C charging with built-in battery
- Over 4,000 units sold — proven track record
- Unbeatable price at $15.83
Cons
- Likely uses a semiconductor CO2 sensor (not NDIR), so precision has limits
- Initial calibration takes some patience
- No English manual included (but it's intuitive enough)
- HCHO readings shouldn't be treated as lab-grade
Who should consider buying this monitor?
- Remote workers who want to know when to open a window
- Parents concerned about air quality in kids' rooms
- Anyone who recently moved into a new apartment or bought new furniture
- Budget-conscious buyers who want a multi-function air quality tool
How can you get the best results?
When you first get it, leave it outside for 10~15 minutes to calibrate against ambient CO2 (~400ppm). Avoid placing it in direct sunlight or right next to an AC vent — both will throw off readings. For the most consistent results, keep it at desk height in the center of the room.
Final verdict
At $15.83, this is a genuinely useful gadget for anyone who spends a lot of time indoors. It won't replace a $200 professional monitor, but for knowing when to crack a window? It's more than enough. With over 4,000 sales and 84.7% positive reviews, it's a safe bet — especially at 52% off.
Frequently Asked Questions
Q: Are AliExpress home appliances good quality?
Many are surprisingly good for the price. Focus on products with high sales volume (1,000+) and positive reviews (90%+). The key is doing your research before buying.
Q: Do I have to pay customs duty in Korea?
Orders under $150 (about 200,000 KRW) are duty-free. Above that, you may pay 8-13% customs duty depending on the product category.
Q: What if the product arrives damaged or defective?
AliExpress has a Buyer Protection policy. You can open a dispute within 15 days of delivery for a refund or replacement. Always save photos and videos as evidence.
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