How to Implement Energy-Saving Strategies in HVAC Cooling Towers

Did you know that HVAC cooling towers can consume nearly one-third of the total energy in an average building?

Over time, however, your cooling tower may become less efficient, causing your energy bills to skyrocket. In addition to regular maintenance, several energy-saving strategies can keep it running efficiently. This not only cuts down your energy bills but also minimizes the risk of breakdowns, repairs, and excessive wear.

So, what are these energy conservation opportunities?

We’ll cover that in this post.

But first, let’s quickly review how HVAC cooling towers work.

How Do HVAC Cooling Towers Work?

HVAC cooling towers use water to help remove heat from your building. Hot water from your building enters the cooling tower and flows over the fill media. Air is blown through the tower, removing heat and evaporating some water. The cooled water then returns to the HVAC system to continue the process.

Cooling towers use electricity to run fans and pumps. While fans move air through the tower, pumps circulate water through the HVAC system. The amount of energy your cooling tower uses depends on its design and how you operate it.

3 Energy Conservation Opportunities for Your Cooling Tower System

HVAC cooling towers have many components, each offering potential energy savings. The trick is to balance your energy usage with your cooling needs.

Here are three proven ways to do this:

1. 1. Optimize Water Flow and Temperatures
   • Choose the Right Size Cooling Tower: Your HVAC cooling tower must be correctly sized for your building. An oversized tower will consume more water and drive up energy bills and wastewater. Conversely, an undersized tower will need to work harder to maintain the desired temperature, leading to frequent breakdowns and repairs.
   • Maintain Water Chemistry: Check and maintain the quality of your water. Water with the correct pH, conductivity, and alkalinity maximizes heat exchange and lowers cooling costs. However, scaling and biological growth can affect its efficiency. Regularly cleaning your HVAC cooling tower and using chemicals to treat the water can help it run efficiently.
2. 2. Use Variable Frequency Drives (VFDs)

   HVAC cooling towers rely on pumps and fans to circulate water and air, which consume more energy than any other part of your system. However, variable frequency drives (VFDs) can help you save energy.

   Here’s how:

   • Adjust Fan Speed: Traditionally, fans run at fixed speeds, wasting energy at low cooling loads and struggling to meet demands at high loads. But VFDs can adjust the fan speed based on the cooling load, which not only saves energy but also prolongs equipment life.
   • Control Water Pump Flow: VFDs can also regulate the water pump flow depending on real-time cooling needs. When the demand for cooling is low, pump flow reduces, saving energy and water.
3. 3. Preventive Maintenance

   Regular preventive maintenance goes a long way in improving cooling tower energy efficiency. It should include:

   • Cleaning: Regular cleaning keeps scaling and biological growth in check, making your HVAC cooling tower more energy efficient. After draining the tower, close all water supply valves and clean every part of the tower, starting with:
     • Clean the fill media thoroughly using a pressure hose
     • Remove the scale, algae, or sediment buildup using suitable biocides
     • Clean the blockages or dirt buildup from drift eliminators
     • Use an appropriate cleaning agent to disinfect the cooling tower and prevent future biological growth
   • Inspection and Audit: When cleaning your HVAC cooling tower, you should check it for:
     • Leaks
     • Galvanic corrosion
     • Equipment damage
     • Scaling
     • Biofilm growth
     • Blocked drift eliminators and filters

Regular preventive maintenance goes a long way in improving cooling tower energy efficiency. It should include:

Use Energy Efficient Components and Materials

• High-Efficiency Fill Media: High-efficiency fill media increases the surface area for water to spread out and cool down. With a larger surface area, the water can cool down more efficiently and your HVAC cooling tower doesn’t have to work as hard. This helps you save energy, reduce heat loss, and lower the risk of frequent breakdowns.
• Drift Eliminators: Drift eliminators capture water droplets that escape with the airflow from the HVAC cooling tower. This helps reduce water loss and the energy required to pump and treat the additional water. Additionally, minimizing water drift helps lower the risk of spreading waterborne contaminants and illnesses, including Legionnaires disease.

How to Implement Energy-Saving Measures:

• Check Your Current Energy Use: First, find out how much energy your HVAC cooling tower consumes. Usually, fans and pumps are the most energy-intensive parts of your cooling tower. Still, a thorough professional energy audit will help you understand which part is consuming more energy than it should.
• Make Upgrades: Once you know where you can save energy, start making upgrades. This may include installing VFDs, upgrading to high-efficiency fill media, and optimizing water flow.
• Monitor Results: After implementing these changes, monitor the results to check if these energy conservation opportunities have paid off. Compare the new data with the old one to see how much energy your cooling tower has managed to save.
• Keep Optimizing: Remember, energy-saving is an ongoing process, not a set-it-and-forget-it strategy. You will need to keep optimizing your HVAC cooling tower to keep it running smoothly and with the highest possible efficiency.

The Bottom Line

Keeping your HVAC cooling tower running efficiently is not a luxury but a necessity. A well-maintained, energy-efficient cooling tower can stand trial of time, lower the risk of unplanned downtime, and save money on costly repairs and replacements. Implement these energy-saving tactics, and your cooling tower will have no trouble running efficiently for a long time.

Want to make your cooling tower more energy-efficient? We can help. Our cooling tower maintenance and repair services are tailored to your needs. Call us to know more!