June 2025 Ian Chiu
When heat wave hits, keeping cool becomes a priority for everyone. Air conditioning is easily a no-brainer option – that is, if you have it. Even so, there are eco-friendly ways to cool off in the heat while avoiding a shocking electric bill. We’ve some of them listed below.
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JISULIFE Ultra-line took handheld fans to the extreme. The first model has gained widespread recognition for its performance as many will find the fan extremely powerful for its size. It, however, has several drawbacks, notably an overly sensitive light switch, weak lighting, and issues with hair being sucked into the fan due to its rear air intake. These issues prompted the redesign of Ultra2 to address the shortcomings of its predecessor.
The latest iteration introduces a number of thoughtful improvements, including the addition of a master switch on the handle, allowing users to control the fan and lighting independently, preventing accidental power drain. The lighting system has been revamped with a larger, circular LED light on the back, offering three brightness levels and an emergency mode – much more practical for outdoor use. The air intake system has also been redesigned with more densely packed vents and a detachable rear cover to reduce the risk of hair clogging and to make cleaning easier. Personally speaking, the lack of mounting support for a tripod is a missed opportunity as it would’ve made it easier to angle the fan in different directions.
In terms of performance, the Ultra2 retains the signature LED display and 100-level wind speed adjustment with a precision scroll wheel. It features a powerful motor capable of 43,000 RPM and delivers airflow up to 17m/s, with improved energy efficiency thanks to a 9-blade fan design. Despite a slightly slower charging time than Ultra1, Ultra2 doubles as a power bank with 18W output. Sound levels are noticeably quieter, ranging from 66dB to 74dB. Even though the JISULIFE Ultra2 carries a premium price tag, it delivers what it’s worth with a balance between novelty and functionality.
USB neck fans aren’t new and there are already more choices than we can possibly ask for. The latest generation of wearable fans has evolved into a jack-of-all-trades thermoelectric personal cooler. Torras Coolify 2S is one such model, featuring two cooling plates that give you the instant sensation of relief from the heat during summer. It is complete with a pair of 5000-rpm fans that provide ventilation around your neck. The Coolify 2S is actually a step-up model that brings all-around improvements over its predecessor.
Based on the same thermoelectric technology used in many beverage chillers and fridges, Coolify 2S can cool down 30°F in less than a second on the part of the neck where the plates come in contact. In comparison, the previous model can do 27°F. The same technology can also be used to generate heat, and as such, Coolify 2 also has the same capability. There’s also app support for those who would rather adjust heat, cooling, and fan controls from their smartphones.
In terms of battery life, the latest model can last for over three and a half hours in maximum power while the last generation can only manage one and a half hour. It’s also worth noting that the bladeless fans are always on in cooling mode. This might explain the fast battery drain but 18W USB-C fast charge on Coolify 2S should reduce the charging time significantly for its 5000mAh battery. Finally, the ability to charge the battery while in use greatly expands the range of applications for the Coolify 2S neck cooler, making it indispensable for hikers, cyclists, and other outdoor enthusiasts.
Much like neck fans, wearable waist fans aren’t a novel concept as they are essentially USB fans worn around the waist or clipped onto a belt. Everyone has their own trick to differentiate their product from the competitors. Coolify Zone from Torras in particular brings phase changing material (PCM) to the game. Presumably, the PCM acts as a heatsink to absorb heat (to a certain extent) from your body. Together with a pair of centrifugal fans that blow air upward at a maximum wind speed of 5.5m/s, Coolify Zone waist fan can reportedly maintain a body temperature of 77F or 25C.
The Coolify Zone has built-in 4000mAh battery that ensures the fans will last for 5 to 15 hours, depending on which of the three wind speed is selected. According to Torras, $120 Coolify Zone is made to complement the company’s highly-praised neck air conditioner. The two work in tandem to improve the air circulation around your body and provide you with some relief during the heat of summer. However, both cost over $300 together, which might not be a price tag everyone can stomach.
Evapolar evaCHILL EV-500 is an evaporative cooler, a USB-powered one at that. In a nutshell, it uses moisture to reduce temperature. This type of cooler works best where the temperature is above 30°C and humidity is below 50%. Conversely, a high humidity level (i.e. above 60%) would render evaporative cooling ineffective.
For the evaCHILL EV-500, a USB fan pushes air through the unit’s filter cartridge that you will need to soak with water first. As hot air comes through water-saturated pads, the water evaporation process begins and gradually lowers the temperature of the outgoing air. The result from our experience was promising with the cooler managing to lower ambient temperature from 29°C to 25°C. You will get even better results if you add in ice water. Though your mileage may vary depending on the humidity. One caveat was that the EV-500 at maximum power did get loud – especially for a USB fan of its size.
Lastly, the basalt-based cartridge does a pretty impressive job at quickly absorbing water and keeping the pads moist. So, you will likely need to refill the evaCHILL’s 800mL tank every 3 to 4 hours depending on the humidity in your room. Also, keep in mind the $20 biodegradable cartridge needs to be replaced every 6 months or so.
Keeping cool is important all year round for those of us who spend most of our time with computers. Torras’ USB fan bar mounts on top of a monitor and is ready to give you a little breeze even if you have limited desktop space. This cross-flow fan provides a 10-inch air outlet with 3-speed settings and vertically-adjustable wind direction.
The Torras also comes with a silicone clip that secures itself to a desktop or a laptop screen, provided the flat panel’s thickness is between 5 and 20mm. However, there seems to be an inherent flaw in the monitor-mounted design in that hot air from some panels’ heat exhaust might get pulled in by the USB fan. If that is the case, then you are simply redirecting the heat towards yourself.