Introduction

How Freon Works Its Magic

At the heart of Freon is a Peltier element, a cutting-edge thermoelectric device that actively transfers heat away from your skin. This isn't just a fan blowing air around ; it's active cooling that genuinely drops the temperature.

But Freon is more than just a powerful cooler – it's smart. Integrated temperature sensors constantly monitor your comfort level, while intelligent controls automatically adjust the Peltier element's intensity and the integrated fan speed. This means:

• Optimal Comfort: No more guessing games. Freon automatically maintains your preferred cooling sensation.
• Energy Efficiency: The system only uses the power it needs, extending battery life and reducing waste.
• Whisper-Quiet Operation: The fan only ramps up when necessary, ensuring discreet and comfortable use.

Freon is controlled at 1Hz allowing a smooth regulation and justifying to promote this project for the "#One Hz challenge" (possibly for the "Ridiculous honorable mention category" !)

Why Freon?

• Instant Relief: Feel the difference immediately as Freon brings down your body's perceived temperature.
• Targeted Cooling: Directly cools your neck, a key area for thermal regulation, providing more effective relief than ambient air conditioning.
• Portable: Lightweight and designed for comfort, you can wear Freon anywhere – at your desk, during your commute, or enjoying outdoor activities. It's not actively discreet but can be hidden under your T-Shirt!
• Personalized Comfort: The smart controls adapt to your needs, not a one-size-fits-all solution.
• No More Discomfort: Stay fresh, focused, and productive, even on the hottest days.

Who is Freon For?

Freon is perfect for:

• Office workers seeking relief from stuffy environments.
• Commuters enduring hot trains or buses.
• Outdoor enthusiasts needing a quick cool-down.
• Anyone who struggles with heat and wants a personal, intelligent cooling solution.

Experience the Future of Personal Cooling

Freon isn't just a gadget; it's your personal oasis of cool, always ready to bring down the heat. Say goodbye to discomfort and hello to a new era of personalized thermal comfort.

Are you ready to "Freeze On Neck" and experience true cool? If yes, follow this project!

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Why is Freon even cooler? Its price

As a DIY device, Freon uses on the shelf components and can be built for less than 30 €

For comparison, the Sony Reon Pro, which is of course a "smarter" system is sold at 327 US$ in Japan ...

Of course the Reon Pro is equiped with two peltier elements acting in "flip/flop", it's an industrial device with quite cool design, it can also act as a heater for winter... But Freon is 10 times cheaper!

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Tell me the truth

As an ingeneer, do I trust all the previous wording, generated by AI, and at the glory of Peltier coolers ?

Of course not... although what is said reflects part of the reality.

Do not expect to have an "incredible" cooling efficiency with a 5x5cm cold metal plate behind your neck... 

But I have tested it and it works quite well to procure a fresh feeling. Blood under your skin will be refreshed and the effect will be clearly perceptible.

If you are still convinced, let's enter into more details and build the Freon !

schematics

schematics are quite simple.

Power

4 x 18650 Li-Ion batteries are wired into a 2s2p pack and can deliver 7.4 V to feed the peltier element.

The module I have choosen is a 12V one able to eat more than 5A... At these high values, this peltier can literally freeze water... and would be dangerous for your skin !

That's why 7.4V is more than enough and we will see later why !

Voltage of this battery pack can be totally cut with a switch to prevent draining the battery, even though this battery is monitored by R15/R16 voltage divider. When voltage is too low, peltier will be cut and ESP32 can go into deepsleep mode.

(Final values for ths voltage divider are 4.7k / 10k. For a full...