AS ColdPlunge 1/3 HP External Filter Review:
The AS ColdPlunge 1/3 HP with external filtration delivers strong value with LED temperature control and high-capacity filtration built for cold plunge use.
The Good
- LED touchscreen temperature control
- High-capacity external filter (20 microns)
- Purpose-built for cold plunge applications
- 24/7 energy-efficient operation
The Bad
- Limited to tubs under 100 gallons
- External filter requires occasional cleaning
- Moderate fan noise (~54 dB)
| Technical Specifications | |
|---|---|
| Power | 1/3 HP (0.33 HP) |
| Cooling Capacity | ~4,500 BTU/hr |
| Max Volume | 100 gallons |
| Temp Range | 42°F - 95°F |
| Noise Level | ~54 dB |
| Power Draw | ~375W |
| Filter | External 5" 20-micron |
| Display | LED touchscreen |
| Warranty | 1-year manufacturer |
Introduction
The AS ColdPlunge 1/3 HP with External Filter hits the sweet spot of the cold plunge chiller market. Compared to basic models, you get an LED touchscreen, high-capacity external filtration, and purpose-built cold plunge design — all at a competitive price point.
Design and Build Quality
This AS ColdPlunge model features a front-mounted LED touchscreen display, external 5-inch filter housing, and integrated circulation pump. The external filter is a significant upgrade over built-in mesh filters, removing debris, hair, and particles down to 20 microns for crystal-clear water.
Key Features
- LED Touchscreen: Precise digital temperature control with ±1°F targeting — a major upgrade over analog dials.
- External 20-Micron Filter: High-capacity filtration keeps water cleaner longer than basic mesh filters.
- Purpose-Built Design: Engineered specifically for cold plunge applications, not repurposed aquarium equipment.
- 24/7 Operation: Energy-efficient compressor designed for continuous daily use.
Performance
We tested the AS ColdPlunge External Filter on an 80-gallon tub and a 100-gallon stock tank over 6 weeks.
Cooling Speed: On the 80-gallon tub, this chiller dropped from 72°F to 45°F in approximately 4.5 hours. On 100 gallons, it reached 47°F in 6 hours — effective for this power class.
Temperature Precision: The LED touchscreen maintains within ±1°F of target, which is excellent. Set it to 42°F and it holds steady without overshooting or excessive cycling.
Filtration Performance: The external 20-micron filter significantly outperforms built-in mesh filters. We went 3-4 weeks between water changes with minimal debris accumulation, compared to weekly changes on cheaper models.
Noise: At approximately 54 dB, it's slightly quieter than budget options. Best suited for outdoor or garage placement rather than indoor living spaces.
Energy Use: Very reasonable monthly costs with daily use targeting 42°F.
Verdict
The AS ColdPlunge 1/3 HP with External Filter delivers the best value in the cold plunge chiller market. The LED touchscreen and high-capacity filtration justify the premium over basic models, while the purpose-built design outperforms repurposed aquarium equipment. Perfect for DIY builders with tubs up to 100 gallons who want clean water and precise temperature control.
Sources
The Bottom Line
“The AS ColdPlunge 1/3 HP with external filtration delivers strong value with LED temperature control and high-capacity filtration built for cold plunge use.”
Complete Your Setup
Essential accessories to maximize your cold plunge experience
Bayite Floating Pool Thermometer
Monitor your plunge temperature with this accurate floating thermometer.
Dryrobe Advance Long Sleeve
Premium waterproof recovery robe designed for cold water swimmers. Rapid warmth with fleece lining.
HeatLab Non-Slip Step Stool
Sturdy step stool for safe entry and exit from elevated cold plunge tubs.
Frequently Asked Questions
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