The Secret Not Mentioned in Small Kitchen Water-Cooled Fresh Air Unit Installation Videos: How Exactly Do You Clear the “Block” Indicator on Puzhe?
When a Small Kitchen Meets a Water-Cooled Fresh Air Unit: A Hard Battle for “Freedom to Breathe”
Commercial kitchen air conditioning and water-cooled fresh air units are essentially “respiratory systems” that provide cooling and ventilation for cooking spaces with high heat, high humidity, and heavy oil fumes. Water-cooled fresh air units use the principle of water evaporation absorbing heat to cool outdoor hot air before sending it into the kitchen, while simultaneously exhausting oil fumes and stale air. For small kitchens with limited space, this system is almost the only solution capable of achieving effective cooling within limited ceiling height and budget. However, after following small kitchen water-cooled fresh air unit installation videos step by step, many users find a puzzling “Block” character appearing on the control panel.
The “Block” Character Is Not a Fault Code—It’s the System “Crying for Help”
The Puzhe water-cooled fresh air unit displaying the “Block” character usually occurs during the initial operation period or in areas with hard water. This character represents “abnormal air resistance” or “blocked water flow,” and is a warning triggered by the equipment’s self-protection mechanism. It does not mean the machine is broken; rather, the system has detected that the resistance in the air intake or water circulation exceeds the design threshold. If this warning is ignored and operation continues, at best the cooling effect will plummet, and at worst the water pump will run dry and burn out. Understanding the physical meaning of the “Block” character is the first step to solving the ventilation and cooling problems in a small kitchen.
Why Is Your Small Kitchen Particularly Prone to “Block”?
Large kitchens have open spaces and flexible duct routing, while small kitchens are often fragmented by wall cabinets, flues, and structural beams. A water-cooled fresh air unit needs to simultaneously accomplish four actions: air intake, cooling, air supply, and air exhaust. Any sharp bend, diameter change, or oil fouling in any section of the duct will cause air resistance to spike. LCCFAIR, in multiple commercial kitchen air conditioning renovation cases, found that over seventy percent of “Block” alarms in small kitchens stem from three avoidable installation mistakes.
Mistake One: Air Intake Too Close to the Stove, Oil Mist Directly Clogs the Wet Curtain
Many installation videos, in order to shorten duct runs, place the fresh air unit’s intake directly above or within one meter to the side of the stove. Oil mist rising during cooking is drawn in by negative pressure and quickly forms an oil film on the surface of the wet curtain. The water film cannot spread evenly, and air resistance naturally increases. The correct approach is to place the air intake at a low position on the opposite corner of the kitchen, allowing fresh air to first cover the personnel activity area, then carry heat and oil fumes out through the exhaust outlet.
Mistake Two: Insufficient Drain Pipe Slope, Water Backup Triggers the “Block” Character
The bottom of a water-cooled fresh air unit has a water collection tray and overflow outlet. The drain pipe must maintain a continuous downward slope of at least 1%. Small kitchen floors are often not properly leveled, creating a “U”-shaped trap in the middle of the drain pipe that prevents condensate from draining. The water level rises and submerges the bottom of the wet curtain, the air intake cross-section is blocked by water, and the control board immediately displays “Block.” The solution is to re-route the pipe or install a micro condensate lift pump.
Mistake Three: Duct Diameter Change Too Abrupt, Static Pressure Loss Exceeds Fan Capacity
Small kitchens have limited ceiling height, so installers often flatten round ducts into ovals to pass through ceiling plenums. This operation reduces the duct cross-sectional area by more than 30%, requiring the fan to run at higher speeds to maintain air volume, increasing noise and current draw. When the system detects the combined signal of abnormal current and insufficient air pressure, the Puzhe water-cooled fresh air unit displaying the “Block” character becomes inevitable. It is recommended to use dedicated transition fittings for flat ducts, with each diameter change section being no less than three times the duct diameter in length.
From Installation Videos to Hands-On Commissioning: Three Steps to Eliminate the “Block” Alarm
Watching the small kitchen water-cooled fresh air unit installation video only completes 50% of the work. The remaining 50% is on-site commissioning and parameter matching. The following three steps apply to most brands of water-cooled fresh air units, including Puzhe, LCCFAIR, and other mainstream manufacturers.
Step One: Clean the Wet Curtain and Filter Screen to Restore Standard Air Resistance
After disconnecting power, remove the wet curtain and rinse it with a soft-bristle brush and neutral cleaning agent until light passes through evenly. If the pre-filter is disposable, replace it directly; if it is washable, let it dry before reinstalling. After cleaning, do not connect the water pipe yet—manually rotate the fan impeller to feel for any sticking or abnormal noise. This step can eliminate 80% of false “Block” alarms.
Step Two: Check the Water Pump and Distribution Pipe to Ensure a Complete Water Film
Power on and let the water pump run alone, observing whether the distribution pipe discharges water evenly. If there is localized flow interruption, it indicates blocked distribution holes, which can be cleared with a fine needle. An incomplete water film causes localized dry burning of the wet curtain, air resistance fluctuating, and the control board frequently reporting “Block.” In areas with hard water, installing a pre-softener is recommended—this is the most easily overlooked long-term solution after the Puzhe water-cooled fresh air unit displays the “Block” character.
Step Three: Use an Anemometer to Measure the Air Outlet and Work Backward to Determine System Resistance
Place the anemometer against the air outlet grille. Normal water-cooled fresh air unit outlet air velocity should be between 3.5 and 5.5 meters per second. If it is below 3 meters per second, system resistance is too high, and you need to check the number of duct elbows, wet curtain permeability, and exhaust louver opening in sequence. Adjust the fan speed setting based on measured data rather than blindly increasing the speed. When the outlet air velocity returns to the design value, the “Block” character usually disappears automatically.
Choosing the Right Manufacturer Is More Important Than Understanding Installation Videos
Commercial kitchen air conditioning and water-cooled fresh air units are equipment with strong installation dependency. The core gap among the top ten brands is not in the compressor or motor, but in duct design and control logic. An excellent manufacturer will provide flat duct solutions for small kitchens, low-noise fan selection, and oil-resistant wet curtain coatings. Conversely, if you only compare prices while ignoring installation compatibility, even the most detailed installation video cannot save equipment that alarms frequently.
LCCFAIR recommends that users request a dedicated duct layout drawing for small kitchens from the manufacturer during the purchasing stage, and confirm whether the control board supports adaptive air resistance adjustment. For users who already have the “Block” alarm, do not rush to replace the mainboard or water pump. First verify item by item using the three-step troubleshooting method in this article. In most cases, a thorough cleaning and duct rectification will restore the equipment to like-new condition.
If you are struggling with a cooling solution for your small kitchen, start by recording the pattern of “Block” occurrences over three days. Does it alarm every time you power on, or after half an hour of operation? Does it resolve after washing the wet curtain, or does it recur daily? Organize these details, then check the ductwork against the installation video. You will find that the key to solving the problem has been in your hands all along.
