Why and How to Maintain Your Water Cooled Chiller During Heating Season
Factory Authorized Service Inc.
It’s fall season, and because temperatures can get chilly even in California (especially in the inland areas in the evening) the chiller tends to be thrust aside while water heaters get all the attention.
Still, chillers represent up to 40% of the energy costs of a building, and the DOE estimates that operational inefficiencies can add up to 30% more energy consumption to the count. At the end of the year, this means thousands of dollars in utility bills.
In colder regions of the country where you can get free cooling from a cooling tower, facilities are able to completely turn off the chiller in the winter. Here in California, however, things are a little different. Because temperatures fluctuate from 40°F to above 70°F in the same week, we enter a tricky period of intermittent system operation that actually demands a lot from chillers.
If you have an older chiller that is moody and inconsistent when the temperature drops, you can do two things: you can rent a unit – which is costly – or you can take the following steps to help your unit perform as designed when the weather gets colder.
1. Clean and Maintain Your Chiller
Keep your coil free of pollutants because they increase thermal resistance, resulting in lower heat transfer capabilities. We recommend that you annually clean and brush the condenser bundle tubes.
Believe it or not, only 1/32” of calcium carbonate deposit will increase energy consumption by about 30%. The deposit increases the refrigerant temperature from the condenser water tubes, requiring the compressor to work harder and at higher pressures to compress the refrigerant.
Make sure that coils within the air handlers are clean, and that filters are also clean and not obstructing air passage.
Lastly, don’t forget to check your tower, pump strainers, and nozzles for free flow for condenser water pumps.
2. Inspect Your Chiller for Leaks
This is a little obvious, but sometimes a leak can go unnoticed for a long time because it hasn’t caused much visual damage yet. However, it is definitely affecting the performance of your unit and impacting your system operation.
Make sure the tubes are clean with no leaks, and that you have treated water running through your system. Check your unit for leaks daily, and also check your coupon racks for leaks or corrosion that can lead to future leaks.
Corrosion in the pipes is usually associated with bad water quality. Therefore, check for water quality daily and eliminate the risk of equipment failure. Water quality monitoring and maintenance is more than a luxury, it’s a legal requirement.
3. Ensure Proper Evaporation
The evaporator removes heat from the water in a closed system, but that doesn’t mean it can be neglected. The evaporator requires attention because the water pressure and temperature inside its tubes are subject to change.
One of the factors that can affect water temperature and pressure is the level of refrigerant running outside these tubes, so that’s another essential item on your list to keep an eye on.
Of course check for refrigerant levels, fluid temperature pressure and temperature in the evaporator daily.
4. Inspect Chiller Piping Insulation
California has a Mediterranean climate that typically experiences dry summers and wet winters, which can be harsh on piping. Facilities have to deal with moisture condensation and mold commonly, and once mold starts, it spreads quickly. To prevent this from happening, many companies in California adopt foam pipe insulation.
If you have foam insulation, make sure that it is in great condition – including the joints, if vapor or water gets inside your insulation, you have to replace the wet insulation and deal with piping rust and corrosion. That means system downtime and unexpected expenses.
5. Analyze Oil and Refrigerant Levels
This is supposed to be easy because you just have to follow the manufacturer’s guidelines. However, try to see beyond what’s happening and investigate WHY it’s happening. For instance, an increase in air-purge time raises a big red flag that you have a leak.
Remember to test refrigerant and oil content to determine contaminants such as moisture, acids, and metals. In centrifugal chillers that are 400 tons or bigger, vibration analysis is recommended.
Don’t forget to keep your cooling towers in good shape for the winter also. They are the main door for everything that enters your HVAC system, and they affect chiller performance directly. Whatever is left untreated in the cooling tower will be carried into your chiller, creating a cascade effect from there.
Put the slower time in now for maintaining your chiller and tower units during winter and guarantee maximum performance when the heavy cooling season comes.
Factory Authorized Service is the only company you’ll need to plan a proper maintenance plan for your chiller—and the rest of your industrial HVAC system. We have experience in servicing all the major brands, including Evapco, Baltimore Aircoil, Marley, Recold, and more! Contact us today to start the process of ensuring your cooling tower is reliable, safe, and performing at optimum energy efficiency.