Liquid cooling / temperature-controlled systems

There are quite a few liquid cooling / temperature-controlled systems on eBay and similar marketplaces, ranging from simple DIY Peltier units to proper compressor-based chillers.

Below are the most relevant types (from what you’re likely after):

🔧 Best overall (simple, ready-made system)

• Typical eBay-style unit
• Closed-loop water cooling with thermostat
• Works like a mini refrigeration system (more stable than Peltier)
• Good for keeping constant temperature automatically

👉 These are the closest to what you described: set temperature → system maintains it.

⚡ Budget / DIY approach (Peltier-based)

• Runs on 12 V DC
• Uses Peltier effect (heat pumped from one side to the other)
• Needs:
  • pump
  • heat sink + fan
  • temperature controller

These are widely sold on eBay (around £20–£60), including listings like a 12 V water chiller module (~£50)

⚠️ Limitation: only small temperature drops (a few °C), and efficiency is poor

🎛️ Essential add-on (temperature control)

• This is the key piece for constant temperature
• You set:
  • target temp
  • hysteresis (e.g. ±1°C)
• Automatically switches cooling on/off

🧊 Higher-end (stable, lab-like performance)

• Much more stable than Peltier
• Can hold temperature very tightly
• Works for larger thermal loads (electronics, experiments, etc.)

🧠 What I’d recommend (based on your use)

• Small experimental / radio gear cooling → Peltier + controller
• Stable long-term temperature (best) → compressor chiller
• DIY hybrid → radiator + pump + controller

⚖️ Quick comparison

👍 Bottom line

• Yes — eBay has exactly what you want
• The type matters more than the listing:
  • Want simple + reliable → go with a water chiller unit
  • Want DIY / experimental → Peltier + controller