How to choose a built-in drinking water machine? The basics you need to know

Hamerson Hao

Nowadays, many people prefer the integrated kitchen design style, where various appliances are built into the cabinetry, creating a more cohesive, aesthetically pleasing, and practical kitchen space. Speaking of built-in appliances, their range is expanding. In addition to the common built-in steam ovens, dishwashers, and integrated stoves, built-in water dispensers have also gained popularity in the past two years.

Built-in water dispensers have become popular due to their unique advantages. Compared to countertop water dispensers, they come with built-in water inlet and outlet pipes, eliminating the need for frequent water replacement. Compared to under-sink water purifiers, they are not only more aesthetically pleasing but also offer more options for adjusting water temperature and volume, making them more convenient to use.

1. Key Points for Choosing a Built-in Water Dispenser

It’s often said that teaching someone how to fish is better than simply giving them fish. So, let me first explain the key points for selecting a built-in water dispenser. Once you’ve learned these tips, you’ll be able to choose one for yourself with confidence.

1.1 Filter Cartridge

The filter cartridge is the most critical component of a water dispenser, as its layers and types directly determine the filtration effectiveness. Additionally, since filter cartridges are consumables that require regular replacement, they significantly impact the long-term maintenance cost. Here's how to choose a filter cartridge, explained in three aspects:

① Layers: Since the water filtered by the dispenser is meant for direct drinking, the cartridge should have at least four filtration layers: PP cotton + granular activated carbon + RO membrane + post-activated carbon. It's worth noting that the number of layers doesn't always correspond to the number of cartridges, as some cartridges are composite, containing multiple filtration stages in one unit.

② Types: Filter cartridges mainly come in two types: single filter cartridges and composite filter cartridges, each with its advantages and disadvantages. Single filter cartridges offer better cost control and are relatively independent, meaning you can replace the specific cartridge that has expired. However, multiple cartridges take up more space, though this is less of an issue for built-in installations. Composite filter cartridges integrate different filtration materials into one, requiring only one cartridge replacement, which is simpler and more convenient. However, since different filtration materials have varying lifespans, it can result in situations where the PP cotton or activated carbon, which have shorter lifespans, expire before the longer-lasting RO membrane, leading to unnecessary waste and increasing future replacement costs.

PP Cotton Filter：

Cartridge Function: Effectively removes sand, impurities, rust, suspended particles, and other contaminants from the water.

Replacement cycle: Every 3-6 months.

Activated Carbon Filter：

Cartridge Function: Removes discoloration, odors, residual chlorine, and some organic compounds from the water.

Replacement cycle: Every 6-12 months.

RO Reverse Osmosis Filter：

Cartridge Function: Removes bacteria, chemical pesticide residues, heavy metal ions, and other harmful substances from the water.

Replacement cycle: Every 18-24 months.

③ Brand: When we talk about brands, we are mainly referring to RO membranes, as their production technology has a higher barrier to entry. Big-brand RO membranes not only offer more stable filtration performance but also have a longer lifespan. On the other hand, PP cotton and activated carbon have lower technological barriers, so the filtration differences between brands are not significant. Below are some of the leading international RO membrane brands for your reference:

2. Flow and Water Production Speed

The flow of a water purifier refers to the total amount of water produced by the RO membrane during continuous filtration for 24 hours, usually measured in gallons (G). 1G ≈ 3.785L. Therefore, the higher the flow, the faster the water production rate. Since the primary function of a water dispenser is to provide direct drinking water, a flow of 500G is generally sufficient for a family of four. For larger families or those who use more water, a higher flow model can be considered. In any case, choose based on your specific needs.

Below is a comparison chart of water production speeds at different flow levels for your reference:

It's worth mentioning that some water purifier RO membrane filter cartridges have lower flux, which theoretically results in a slower water production rate. However, they may still have a high water output speed (note that this is not the same as the water production speed) because they are equipped with an internal water tank that stores a certain amount of purified water to avoid slow output. However, this design has two drawbacks:

1) If the water purifier is not used for an extended period, the purified water in the tank can become stale and lose its freshness.

2) If there is frequent, large water consumption in a short period, the water tank may not be able to maintain a high output speed, and you may encounter a wait time for water production.

3. Heating Element Type

To meet users' drinking needs, water dispensers generally come with built-in heating elements that can provide drinking water at different temperatures. The common types of heating elements are the tank-style and tankless types, each with its own advantages and disadvantages:

Tank-style heating elements provide stable water output as they can store hot water in the tank. However, they heat the entire tank's water each time, which leads to slower heating speeds and may result in issues like over-boiled water or secondary contamination.

Tankless heating elements, on the other hand, heat water as it flows through the heating unit, completing the process instantly. Thick-film heating technology, in particular, can achieve rapid heating in as little as three seconds. However, it may face challenges if the water production speed at the front end cannot keep up with the heating speed, leading to unstable output and problems such as dry burning or steam spitting.

4. Cooling Element Type

The common types of cooling elements include compressor cooling and thermoelectric cooling:

Compressor cooling achieves refrigeration through heat exchange between the condenser and the evaporator. It offers faster cooling but has a larger size and requires the use of refrigerants.

Thermoelectric cooling, on the other hand, uses semiconductor cooling chips. It is compact, energy-efficient, and environmentally friendly but provides slower cooling.

If you don't need large quantities of continuous cold water, thermoelectric cooling is sufficient. However, if there is a higher demand for cold water, compressor cooling is the better option.

Additionally, built-in water dispensers often come with APP control options and WiFi (IoT) capabilities, fully synchronized with the operation panel. Practical features such as TDS value display, filter status monitoring, and recommended modes enhance usability.

With integrated water filtration, the ability to cool water, make ice, produce water at various temperatures instantly, and provide boiling water, these multifunctional dispensers serve multiple purposes in one device.