Air Cooled Products CGAM, RTAC, RTAF, ACR, ACS:
If during the process of being serviced and service work is interrupted or delayed, the chiller should be hermetically sealed, evacuated and charged with 5 – 10 psi of dry nitrogen until the service can be completed.
If a chiller has not been installed, please follow the Storage Requirements as called out in the IOM.
If a chiller has been installed and the startup will be delayed, follow the Storage Requirements as called out in IOM. If water is in the water loop and has been running through the chillers heat exchanger; the main concern is a heat exchanger ambient freeze.
Freeze Avoidance for Air-Cooled Chillers
When dealing with air-cooled chillers, it is crucial to implement effective freeze avoidance strategies to prevent damage and ensure optimal performance. The appropriate method for freeze avoidance will depend on the geographical location of the jobsite. Below are three recommended options:
- Continuous Pump Operation: Keeping the pumps running ensures that the chilled water or glycol solution remains in motion, preventing it from freezing. This method is particularly effective in regions where temperatures occasionally drop below freezing but do not remain low for extended periods.
- Use of Freeze Inhibitors: Adding a freeze inhibitor, such as glycol, to the chilled water system can lower the freezing point of the solution. This method is suitable for areas with moderate freeze risk. Ensure that the concentration of the inhibitor is adequate for the expected minimum temperatures.
- System Draining: In locations where prolonged freezing temperatures are expected, or if the system will be inactive for an extended period, draining the chilled water solution from the heat exchangers is the best option. This prevents any risk of freeze damage to the system components.
Geographical Considerations
The location of the jobsite plays a significant role in determining the best freeze avoidance method. For instance, south of the Mason-Dixon Line (approximately Latitude 39 degrees, 43 minutes), freeze avoidance is generally less of a concern, especially during this time of year in the USA.
Best Practices
- Avoid Stagnation: It is essential to prevent treated or untreated water from becoming stagnant in the heat exchangers, as this can lead to severe damage. Regular circulation of the solution helps maintain system integrity.
- Monitor Ambient Conditions: If the pumps will not be running and there is a risk of ambient temperatures causing the solution to freeze, draining the system is the safest option until startup can be performed.
By following these guidelines, owners can effectively manage freeze risks and ensure the longevity and reliability of air-cooled chiller systems.
EXAMPLE OF FREEZE AVOIDANCE SECTION WITHIN THE IOM:
Water Cooled Products RTWD/UD and RTHD:
If in the process of being serviced and service work is interrupted, the chiller should be protected from developing internal corrosion. If the refrigerant/charge has been removed, but still hermetically sealed, evacuate the chiller and charge the chiller with 5 – 10 psi dry nitrogen.
If a chiller is in the process of being dissembled, follow the procedures as called out in RLC-SVB41*-EN & RLC-SVG003*-EN for RTWD/UD chillers or RTHD-SVB02*-EN for RTHD chillers.
For new chillers that have not been installed, please follow the Storage Requirements as called out in the IOM.
For new equipment that has been installed and the startup will be delayed, follow the Storage Procedures as called out in the IOM as well. If protective shipping coverings have been removed, they should be reinstalled until the chiller is commissioned. It is best to NOT let treated or untreated water become stagnate in the heat exchangers (severe damage may occur).
Products:
- ACR (air-cooled)
- ACS (air-cooled)
- CGAM (air-cooled)
- RTAC (air-cooled)
- RTAF (air-cooled)
- RTHD (water-cooled)
- RTWD (water-cooled)
- RTUD (water-cooled)
HUB Document Number: DOC-184294
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.
OC-14294