During the cold spell, central air conditioning systems, especially water system units, face the risk of cracking, which may lead to significant economic losses.
The following summarizes key protective measures by scenario:
One: Continuous Operation of Central Air Conditioning Throughout the Winter
Core Principle: Stay Connected Endless Loop
1、24/7 Power On: The engine and pump must remain powered on at all times to ensure the automatic frost protection function is activated. Power shutdown will deactivate the frost protection.
2、Maintain Water Circulation: Pumps and main units must be interconnected; the pumps should have a forced start-up function during standby mode, and when the water temperature falls below the set value (usually...4°C automatic start of the circulation
3、Add Antifreeze: Mix ethylene glycol antifreeze into the water system proportionally to lower the freezing point below the local lowest temperature (recommended)Below -25℃
4、Water Temperature Monitoring: Ensure the water supply temperature is appropriate, avoiding excessively low temperatures. Check the system water flow and temperature before starting up daily.
Long-term Disuse of Central Air Conditioning During Winter
Core Principles: Draining Stored Water or Filling with Antifreeze
When the ambient temperature falls belowAt 2°C, one of the following measures must be taken:
SolutionA: Thoroughly drain the system
Open the evaporator and condenser drain valves and vent valves, and clean the remaining water with compressed air.
At the end, open the condenser exhaust valve and drain valve, and blow out the stored water in the coil with high-pressure gas.
Turn off the inlet and outlet valves, open the drain valve and the vent valve to empty.
Pipe: Open the lowest valve of the system to drain all standing water; also, the cooling tower's water supply pipe needs to be emptied.
SolutionB: Add antifreeze
Add ethylene glycol solution according to concentration requirements (refer to the concentration vs. freezing temperature chart in the equipment manual).
Ensure that the antifreeze is fully circulated throughout the entire system, including the main unit, pipes, and ends.
Section 3: Special Protection for Air Handling Units
Direct contact with outdoor cold air in air-cooled chillers for new ventilation units presents the highest risk of cracking.
1、Install Electric Insulated Damper: Linked with the unit, it automatically closes during shutdown to prevent cold air backflow.
2、Pre-start Inspection: Ensure the pump is operating and the water temperature meets standards before turning on the air handling unit.
3、Reduce fresh air intake: During cold spells, slightly close the fresh air valve to minimize direct cold air flow.
Preparation for Cold Front Inspection
1、Cleaning and Maintenance: Clean dust from indoor and outdoor units, particularly the air filters, to ensure efficient heat dissipation and heating.
2、Test Run: Power OnWithin 15-20 minutes, the temperature at the air outlet 10-20cm should be ≥15°C; otherwise, maintenance is required.
3、Verify Interlock Protection: Confirm that the water flow switch is properly interlocked with the unit to prevent water loss from causing freezing.
V. Emergency Response in Extreme Situations
In the event of a power outage or equipment failure:
Immediately manually drain water from the equipment and pipelines (refer to equipment draining signage).
Do not force-start pumps or pipelines that have frozen over; instead, use hot water to thaw them.
VI. Other Important Reminders
1、Set Temperature: Avoid setting the heating temperature too high; recommended...20-22°C, energy-efficient and comfortable
2、Outdoor Unit Protection:加装 anti-wind deflector to external units to prevent cold north winds from directly blowing onto the heat exchanger
3、Routine Inspections: Monthly check of refrigerant pressureThe 410A model should have a low pressure of ≥0.8 MPa at -15°C.
4、Professional Support: For complex operations, please contact a professional maintenance team. Freeze cracking damage is generally not covered under warranty.
