AS ColdPlunge 1/3 HP Review: Budget Cold Plunge Chiller

Introduction

The AS ColdPlunge 1/3 HP Chiller is purpose-built for cold plunge applications, unlike aquarium chillers that are repurposed for cold therapy. This dedicated design includes everything you need: built-in circulation pump, metal filter, and insulated hoses that prevent heat gain during operation.

Design and Build Quality

AS ColdPlunge designed this unit specifically for the cold plunge market. The integrated pump eliminates the need to purchase separate circulation equipment, and the built-in filter removes debris, hair, and particles down to 20 microns. The insulated hoses are a thoughtful touch that prevents the water from warming as it cycles through the system.

Key Features

• Built-in Pump: No need to buy a separate circulation pump — saves $50-100 and simplifies installation.
• Metal Filter Included: 20-micron filtration removes debris and keeps water clean between changes.
• Insulated Hoses: Prevents heat gain during circulation, improving efficiency by 10-15%.
• Cold Plunge Specific: Designed for cold therapy, not repurposed from aquarium use.

What to expect

We haven't tested this unit ourselves. This section is based on the manufacturer's published specs and general chiller sizing.

Cooling: AS ColdPlunge rates this 1/3 HP unit (about 4,200 BTU/hr) for tubs up to 79 gallons, with 50-70 gallons as the best fit, down to 42°F. Expect slower pull-down near the top of that range and in hot weather; a lid and an insulated tub help.

Temperature control: It uses a basic analog thermostat, which is less precise to set than a digital display.

Noise: The listed noise level is about 55 dB, so a garage or outdoor spot suits it better than a living space.

Energy use: The listed power draw is about 360W while the compressor runs. Monthly cost depends on climate, insulation and your electricity rate.

Included accessories: The built-in pump, washable metal filter and insulated hoses come in the box, so there is no separate circulation pump to buy.

Verdict

The AS ColdPlunge 1/3 HP is a budget chiller designed for cold plunge use. Unlike aquarium chillers that require separate pumps and improvised filtration, this all-in-one unit includes everything you need. The insulated hoses and dedicated cold plunge design set it apart from repurposed aquarium equipment. Best choice for first-time cold plungers with tubs under 80 gallons.

Sources

• NLM: Cold Water Immersion and Recovery
• DOE: Pump Up Your Savings with Heat Pumps