When the weather starts to cool down, it’s the perfect time for homeowners to think about winterizing their commercial buildings. All systems like domestic sprinkler systems for example likely to be exposed to the cold, including automatic sprinkler systems for fire protection, are particularly vulnerable.
One of the major reasons sprinkler systems fail is improper maintenance. These systems can freeze, burst, leak, cause water damage, and stop working in the case of a fire if they are not correctly maintained. Because of this, it’s crucial to confirm that your sprinkler system has been correctly winterized, inspected, tested, and maintained by a qualified contractor. In places where you cannot maintain an appropriate heating temperature, a pipe sprinkler system (which does not contain only air in the pipes) could be used in place of the wet pipe sprinkler system in most buildings. Either way, wet or dry systems require proper maintenance to prevent freezing or breakage when the temperature drops.
Pipe Sprinkler Systems
A dry system uses nitrogen or pressurized air to charge/monitor the system so there is no water in the pipes. Instead, if the system is activated, water is released through a differential valve. Dry systems are usually used in unheated warehouses, underground parking garages, and outdoor loading docks.
However, there are always wet components in a dry system, especially at the junction between the water supply line and the differential valve, and these components must be maintained above 4°C. During the winter months, a dry system that is not properly maintained could freeze or burst. It can also freeze due to improper positioning of the sprinkler pipe.
As part of an annual inspection, a qualified contractor should flush a dry pipe system’s low point or auxiliary drains. However, the building owner must also continue to check the system’s condition and drain it if necessary. In freezing weather, it is recommended to check the temperature daily in the rooms where the differential valves are located.
Wet Sprinkler Systems
In a wet pipe system – the most commonly used sprinkler system for fire protection – the pipes are filled with water and ready to discharge in the event of a fire. However, if their temperature is too low, they can freeze and burst, causing significant water damage. “The key here is to maintain adequate heating, even if the workers are not present regularly. But don’t use temporary heaters, as that is a fire hazard.
Some wet installations use antifreeze to protect pipes from freezing, but it is important to test the antifreeze solution annually before winter. Glycerin-based antifreeze can be used in plastic (CPVC) and steel sprinkler systems, while propylene glycol should only be used in steel systems. It is also important to determine the percentage of antifreeze required in the solution according to NFPA standards (or use a commercial pre-mixed solution), keeping it to the minimum necessary to withstand the lowest expected temperature. If the antifreeze solution circulating in the system is not maintained at the proper concentration, it could freeze.
