How does an under-sink reverse osmosis system work?
An under-sink RO system connects to your cold water supply line beneath the kitchen sink. Water passes through a sediment pre-filter, a carbon block filter, then the RO membrane (which rejects up to 99% of dissolved contaminants), and finally a post-carbon polishing filter before reaching a dedicated drinking water faucet. Clean water is stored in a pressurized tank until needed.
How much space does an under-sink RO system require?
Most AMPAC under-sink RO units have a compact footprint of roughly 14" wide × 5" deep and sit alongside the storage tank (typically 10–14" tall, 10" diameter). The system fits comfortably in standard kitchen cabinets. Compact tankless versions are also available for tight spaces.
What is the water waste ratio for under-sink RO systems?
Traditional RO systems produce 3–4 gallons of drain water for every 1 gallon of purified water. AMPAC high-efficiency models achieve ratios as low as 1:1 using permeate pumps and smart flow control, significantly reducing water waste compared to older designs.
Does an under-sink RO system require a plumber to install?
Most homeowners with basic DIY skills can install an under-sink RO system in 1–2 hours using the included fittings and instructions. A saddle valve connects to the cold supply, and the drain saddle clamps to the existing drain pipe. If you prefer professional installation, any licensed plumber can complete the job quickly.
How long do the filters last in an under-sink RO system?
Pre-filters last 6–12 months, the RO membrane 2–3 years, and the post-carbon polishing filter 12 months under average household use. AMPAC systems include filter life indicators, and replacement filter sets are available for convenient annual servicing.