Five things you need to know about chilled water systems
Maintenance service of industrial construction facilities
You may already know that cold water is a vital resource of the HVAC system. But why is it so important? And which parts of the system need special attention? How to keep the installation healthy and in good condition and prevent problems? Here’s what you need to know.
The temperature range of the cold water system is 6 to 12 degrees Celsius or 5 to 11 degrees Celsius, with a temperature difference of six degrees.
Cold water is produced by a chiller – in other words, it is created artificially. The chiller can be considered the heart of the system and the cold water pipes can be considered its arteries
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۱. The importance of glycol
The water inside the pipes is a mixture of water and glycol, a product that prevents water from freezing. The higher the glycol ratio in the system, the lower the freezing point of the mixture: for example, a glycol content of 10 temperatures reduces the freezing point to -4 ° C. In addition to protecting water from freezing, glycol also protects the tubes themselves: they are slightly greasy, leaving a film inside the tubes and protecting them from corrosion.
۲. Specific heat reduction
Cold water acts as an energy carrier because it flows into the heat exchangers of the fan coil units and the cooling coils of the air conditioning units. Here, it removes heat from the environment and returns it to the chiller, where it cools. Pure water naturally has a high specific heat capacity (the amount of energy that must be removed to reduce its temperature). The higher the amount of glycol in a system, the lower its heat capacity.
Maintenance service of industrial construction facilities
۳. Adjust the water
The capacity of a cooling coil, in addition to the specific heat and temperature, depends on the flow of the environment, i.e. the amount of cold water that passes through the pipes. When a fan coil in the bidding garage, for example, no longer cools, this could be a sign of a flow problem. You may be able to prevent this by setting the installation to function properly. Proper installation ensures that cold water is well distributed among users and also prevents cavitation and noise problems.
۴. Air issues
One of the most common cold water problems is the air inside the system, which appears as small bubbles that collect in the pockets. They block the flow of water and dry the heat exchanger so that it no longer cools. This is especially true after the delivery of a new ship and the cold water still contains a lot of common air. Installing automatic air filters prevents this from happening. It is important to note that the position of the filters is very important for their proper operation. Air is lighter than water, so it tends to accumulate in higher parts of the system. To ensure the best results, the filter should be placed at the highest point.
۵. System filtering
Although cold water lines are thoroughly rinsed before operation, stains always form inside the lines, for example coming out of heat exchangers installed inside air transfer units. The use of filters prevents the particles in the cold water from abrasing components or clogging narrow pipes. Existing filters range from solid tube filters to advanced filtration units that filter even air and keep the pH level high.
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Maintenance service of industrial construction facilities
