這篇文章主要記錄由 2014 年開始到 2018 年的便攜式冷氣機（空調）開發計劃的所有版本及失敗原因。由於此計劃已經完成，現在在此作開源處理。
授權：姓名標示-非商業性-禁止改作 3.0 香港 (CC BY-NC-ND 3.0 HK)
Short for PA#, The version number is represented by #.
Aim
This project aims to design and create the world’s first Thermoelectric Plate based portable air cooling devices with a target of handheld and at least 1 hour running time.
Budget Limit
The budget has been limited to less than 1000HKD per prototype.
And the manufacturing price of raw material (excluding shipping) should be lower than 100HKD.
The design of PA1 to PA5 did not have any prototype as there are still design problems inside the sketch that made the sketch not possible to manufacture. Reference design sketches are included as reference.
The first success prototype of the Portable Air Conditioner Project.
System wiring 
The PA07 was similar to PA06 but with more solid casing with cardboard instead of paper cards.
Cooling Unit 
The PA08 was the first prototype for self contained Portable Air Conditioner with standard forward Peltier Design.
Internal Structure
The portable air conditioner version 9 was the first version that make use of Aquatic Plastic Casing to protect the internal circuitry and make it easier to carry.
slightly different wiring circuitry.
This version was special made for Nelson ***. This version uses 24DC FAN instead of 12V DC Fan to reduce noise produced from the FAN.
PA12 was the slim down version of Portable Air Conditioner v11 with the temperature sensor removed and replaced with an mechanical temperature switch for turning on the cooling fan.
PA13 was the first version with High Power Input (12V 6A) that can generate cold wind. However, the size of the machine is too big for portability. Hence, this version was not
matched the portable requirement. But this devices provided insight for future cold wind
versions. (The most left one in the picture below)
The PA14/15 version consists of an electronic circuit that is based on Arduino Nano v3. As the developer did not have enough skills in PCB and SMD electronic manufacturing, this version of PA development has been terminated.
The portable air conditioner version 16 and 17 rely on the chemical properties of NH4Cl in which its latent heat of solid to liquid will absorb heat. However, version 16 was terminated as it is single use only. Version 17 was also terminated due to the evaporation of NH4Cl solution.
Part of the Ammonia has been released to the environment, leading to an
unpleasant smell of the machine and the H+ properties of the remaining solution lead to
corrosion to the metal part of the device.
PA18 has been terminated because of the need for a water tank. In which when placed in bags, the water tank might leak and lead to a short circuit. Hence, no prototype was made for this version.
PA19 was checked to have design problems. 3.7V LiPo cannot provide enough voltage for cooling down the air in the surrounding.
No prototype for this version.
This version of PA uses a sealed water tank and flow area for water cooling. However, the
heat contact position of the hot side of Peltier requires custom made metal parts in which is
too expensive to produce.
The PA21 / 22 was designed with a much greater heat sink and cooling fan. But after testing
with the 6cm High Power fan, it was discovered that the battery cannot be placed directly on
the device as the device gets over heated over time.
Cooling Core is shown in this picture.
cool air by passing warm air sucked in from the surrounding and cool it using a peltier
module. The air flow is small in PA23 Prototype, but the temperature can reach 20 degree
celsius with an environment temperature of 29 degree celsius. This is also the first version of
PA that is controlled by Tinduino from the Tinduino Project. The cooling core is shown in the
picture below.
The PA24 suggested the use of Copper Heat Pipe to transfer the heat to a secondary heat
sink. However, with reference to the PA23, the design is too tall and not convenient to hold
on hand.
The PLA made Wind Directional Tunnel was introduced to PA25 for concentrating the wind outlet for much cooler feel. The image was not included in this report.
The Wind temperature and speed is much better than the previous prototype. However, the wind is not cold enough to feel like an air-conditioner. The cooled air generated by this prototype only feels a little bit cool under hot summer days.
*This battery structure is designed to charge with 5V 2A
The PA26 design with 18650 (made in Japan) and SABC3.3 (Ultra compact version of SABC3) . This version has a size similar to PA11 with cold wind blowing outward from the top. PA26 has built in 3.7V 3200mAh battery x4 with charging current max out at 5V 2A (SABC 3.3). Battery array output at max 7.4V 6A but the TEC-12705 usually draw around 2A max under idea conditions. This is the final development version of the Portable Air Conditioner Project.
This project has successfully invented the portable air conditioner with cold breeze without the need of water.
Project finished on 1-7-2018 (Sun) 8:42pm