What Size Chiller Do You Need for a Cold Plunge?

For most home cold plunges, a 1/2 HP water chiller is the right size. It has enough power to reach and hold 39°F in a real garage, without the cost and overkill of larger commercial units. Here is how to choose.

Cold Plunge Chiller Sizes Explained

• 1/3 HP: Fine for small tubs in cool climates, but often struggles to hold temperature in a warm garage. Many people outgrow these quickly.
• 1/2 HP: The sweet spot for single-person home plunges. Holds 39°F reliably, even through summer heat. This is what powers the Temp Drop Cold Plunge.
• 3/4 HP to 1 HP: Built for large tubs, multiple users, or commercial settings. Usually more than a home user needs.

What Happens if Your Chiller Is Too Small?

An undersized chiller runs constantly, never quite reaches your target temperature, and wears out faster. This is the most common complaint with cheap 1/3 HP units in warm garages. Sizing up to 1/2 HP solves it.

Does Ambient Temperature Matter?

Yes. The hotter your space, the harder your chiller works. A unit rated for a cool basement may fail in a 90°F garage. We engineered our 1/2 HP chiller specifically to hold 39°F in real-world heat.

What Size Chiller for a Stock Tank or DIY Plunge?

For a standard 100-gallon stock tank used by one person, a 1/2 HP chiller is ideal. Our 1/2 HP Water Chiller connects to most tubs, tanks, and pods with built-in hose fittings.

Questions about your specific setup? Reach out. We are a San Diego family business and happy to help you size it right.