THE DIFFERENCE BETWEEN FREEZE AND BURST PROTECTION: (DOW CHEMICAL 1 )
Burst protection is required if your heating system/fluid will sit dormant at temperatures below freezing without being pumped, putting the pipes in danger of bursting. For these situations a slushy mixture is acceptable, because the fluid will not be pumped through the system. A slushy mixture is one that contains water and glycol, but as mixture of liquid and frozen ice crystals. Trying to pump fluid containing ice crystals can result in damage to system components. Since the mixture expands as it freezes, there must be enough volume available in the system to accommodate the expansion. Freeze protection is required if your heating system/fluid is going to be pumped at temperatures at or below the freezing point of the fluid. For example, systems that are dormant for much of the winter, but require start up during the cold weather, or systems that would be at risk if the power or pump failed. For these situations, the system must have enough glycol present to prevent any ice crystals from forming. It generally requires more glycol for freeze protection, keeping the fluid completely liquid, than it does for burst protection, where a slushy mixture is acceptable.
PUMP LAWS AND FAN LAWS:
Depending on the application, a pump or fan may need to be sped up or slowed down to achieve the desired function in a heating system. Use the following handy equations to calculate the increase or decrease in flowrate, pressure, and power consumption based on the original and the new pump or fan speed (RPM).
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FANS
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1 https://dow-answer.custhelp.com/app/answers/detail/a_id/5206/~/lttf---burst-protection-vs-freeze-protection- for-glycol-based-heat-transfer
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Hydronic System Design Manual ©DECTRA CORPORATION - March 2013
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