Differences Between Tankless and Tank-style Under-sink RO systems

These days, under-sink reverse osmosis (RO) systems have become increasingly popular for providing healthy drinking water. As more people turn to RO systems to produce pure water, it’s important to understand the differences between the two main types. In this article, we’ll compare tankless and tank-style under-sink RO systems.

Design & Space Requirements

• Tankless RO Systems:
  • Compact Design: Tankless systems are more compact because they don’t require a storage tank. This makes them ideal for situations where under-sink space is limited. Normally, tankless systems saving up to 75% spaces than traditional tank-styles.
  • Modern Look: The lack of a tank gives a sleeker appearance and allows for more versatile installation options.
• Tank-style RO Systems:
  • Bulkier Design: These systems include a large storage tank, which takes up more under-sink space. The tank is used to store purified water, ready for use.

Water Production & Flow Rate

• Tankless RO Systems:

  • On-Demand Filtration: They produce filtered water on demand, which means there’s no waiting for a tank to fill up. However, the flow rate can sometimes be lower than a tank system because the water is being filtered in real time.
  • Consistent Flow: Modern tankless systems are designed to maintain a consistent flow, though they might not be as fast as tanked systems.

• Tank-style RO Systems:

  • Stored Water Supply: The water is filtered and stored in the tank, which allows for a faster flow rate when the tap is turned on because the water is already filtered and ready to use.
  • Flow Dependent on Tank Size: The flow rate is high until the tank is depleted. After that, you must wait for it to refill and re-pressurize.

Water Efficiency

• Tankless RO Systems:
  • More Efficient: Generally, tankless systems waste less water because they continuously adjust the water production to the demand, reducing the amount of wastewater produced.
  • No Water Stagnation: Since water isn’t stored in a tank, there’s no risk of water stagnation, which can lead to bacteria growth.
• Tank-style RO Systems:
  • More Waste: These systems can be less efficient, often wasting more water in the filtration process.
  • Potential for Water Stagnation: Stored water in the tank might stagnate over time, especially if not used frequently, leading to potential contamination risks.

Maintenance & Longevity

• Tankless RO Systems:
  • Simpler Maintenance: These systems often have fewer components, leading to potentially lower maintenance. However, the filters and membranes still need regular replacement.
  • Longer Filter Life: Because the water is filtered on demand, the filters may last longer compared to tank systems, depending on usage.
• Tank-style RO Systems:
  • More Components to Maintain: The tank and additional components mean more parts that might require maintenance or replacement.
  • Tank Maintenance: The tank itself may require periodic cleaning to prevent bacterial growth.

Cost

• Tankless RO Systems:
  • Higher Initial Cost: Generally, these systems are more expensive upfront due to their advanced technology and compact design.
  • Lower Long-term Costs: Potentially lower ongoing costs due to higher water efficiency and fewer maintenance needs.
• Tank-style RO Systems:
  • Lower Initial Cost: These systems are typically less expensive upfront.
  • Higher Long-term Costs: They may have higher ongoing costs due to water waste and more frequent maintenance needs.

Installation

• Tankless RO Systems:
  • Easier Installation: The compact design and fewer components often make installation easier and more flexible.
• Tank-style RO Systems:
  • More Complex Installation: The tank and additional parts can make installation more complex, requiring more space and time to set up.

Which type would you choose? We’d love to hear your thoughts!