Water-cooled air conditioners offer a unique approach to home cooling. Unlike traditional air-cooled systems, these units use water to transfer heat, potentially leading to greater energy efficiency and quieter operation. For homeowners looking to save on energy costs or reduce noise, a water-cooled air conditioner is the perfect choice. In this guide, I’ll explore everything you need to know about water-cooled air conditioning systems, helping you understand how they work, their benefits, and potential drawbacks.
Still wondering how these HVAC units operate? Watch this video from ACS Installations to understand what water-cooled units are and how they work:
How Water-Cooled Air Conditioners Work
Water-cooled air conditioners operate on a principle different from traditional AC units. These systems use a constant flow of water over the condenser coil to transfer heat. This process is generally more efficient than using air, as water has better thermal conductivity. Once the AC unit transfers heat to the water, it drains or recirculates through a cooling tower for less waste.
The Cooling Process
In a water-cooled system, warm air from the home is drawn over cold evaporator coils, much like in a traditional AC unit. The refrigerant inside these coils absorbs heat from the air, cooling it before it’s circulated back into the home. The now-warm refrigerant travels to the condenser, where it’s cooled by water flowing through the system. This cooled refrigerant then returns to the evaporator coils to repeat the process.
Water Supply and Circulation
Water-cooled air conditioners require a connection to the home’s water supply. You can set the system up to use fresh water continuously or to recirculate water through a cooling tower. The choice between these options often depends on local water availability and regulations.
Types of Water-Cooled Air Conditioners
There are three main types of water-cooled air conditioner condensers, each with its own design and application.
This is the most common and simplest design for water-cooled air conditioners. It consists of an inner tube inserted into a larger outer tube, both formed into a coil shape. Water moves through the inner tube to cool the refrigerant in the outer tube. As they move, the water and the refrigerant flow in opposite directions, known as a counter-flow arrangement, to maintain consistent temperatures during heat transfer.
The shell and coil configuration uses a steel shell with a copper coil inside. Water flows through the coil to cool the hot gas refrigerant in the shell. As hot air flows from the top of the shell, it condenses upon contact with the coil, reaching a subcooling state at the bottom of the shell.
This design, primarily used in large industrial settings, consists of a steel shell with copper tubes inside. Water flows through the tubes to cool the refrigerant in the shell. The robust design makes it suitable for heavy-duty cooling applications.
Advantages of Water-Cooled Air Conditioners
Water-cooled air conditioners offer several benefits that make them an attractive option for some homeowners.
Energy Efficiency
One of the biggest advantages of water-cooled systems is their superior energy efficiency. Water has better thermal conductivity than air, allowing these systems to transfer heat more effectively while using less energy. According to Energy Resources Group, water-cooled AC systems can be up to 215% more energy-efficient than standard air-cooled units, potentially leading to significant savings on electricity bills.
Quieter Operation
Water-cooled systems typically operate more quietly than air-cooled units. This is because they often use a separate chiller plant or cooling tower, which is often set apart from living spaces. Additionally, the cooling process itself generates less noise, as it doesn’t rely on large fans to move air over the condenser coils.
Durability and Longevity
Water-cooled units are often built with higher-quality components than their air-cooled counterparts. This superior build quality can result in a longer lifespan and more reliable performance over time. While this may mean a higher up-front cost, it can lead to savings in the long run through reduced repair and replacement needs.
Disadvantages of Water-Cooled Air Conditioners
Despite their advantages, water-cooled air conditioners also come with some potential drawbacks that homeowners should consider.
Water Supply Requirements
These systems require a constant water supply to function effectively. This can be problematic in areas with water scarcity or unreliable water pressure. A one-ton water-cooled AC unit may need up to three gallons of water per minute for optimal performance, which can be a significant amount over time if not recirculated.
Maintenance Needs
Water-cooled systems can be more maintenance-intensive than air-cooled units. The continuous movement of water can lead to mineral deposits and scale build-up in the pipes, requiring regular cleaning to maintain efficiency. Additionally, the water quality can impact the system’s performance and longevity, potentially necessitating water treatment in some cases.
Risk of Corrosion
The constant exposure to water can lead to corrosion of the AC unit’s components, especially if the water quality is poor. This can result in more frequent repairs and may shorten the lifespan of the unit if you don’t manage it properly.
Higher Initial Costs
While water-cooled air conditioners are often more cost-effective over time due to their energy efficiency levels, they have higher up-front costs for equipment and installation. This can make them less accessible for some homeowners, particularly those on a tight budget.
Using a Cooling Tower For Water-Cooled Air Conditioners
Instead of pouring the hot water down the drain after it’s used, you can recirculate the water by using a cooling tower. Simply pipe the water away from the AC unit and into the cooling tower, then send the cooled water back to the condenser so the whole process can repeat itself.
Cooling towers use two common types of heat rejection methods: natural draft, which uses air to cool the water, and forced draft, which uses a fan to move air over the warm water.
Water-Cooled Vs. Air-Cooled Air Conditioner Video Overview
Benefits of Cooling Towers
Using a cooling tower with a water-cooled air conditioner can significantly reduce water waste. It also allows these systems to be used more efficiently in areas where water conservation is a priority. However, cooling towers do require additional space and maintenance, which you should factor into the decision-making process.
Comparing Water-Cooled and Air-Cooled Systems
When deciding between water-cooled and air-cooled air conditioners, homeowners should consider several factors.
Energy Efficiency
Water-cooled systems generally have the edge in energy efficiency, especially in larger applications. They can operate at lower condensing temperatures, which helps to alleviate the workload on the compressor and, in turn, saves energy.
Installation and Maintenance
Air-cooled systems are typically easier and less expensive to install, making them more common in residential settings. They also tend to require less maintenance. Water-cooled systems, while more complex to install and maintain, can offer better long-term performance in the right situations.
Environmental Impact
The environmental impact of water-cooled air conditioner systems can vary. While water-cooled systems are more energy-efficient, they consume water, which can be a concern in water-scarce areas. Air-cooled systems don’t use water but may consume more electricity. The best choice often depends on local resources and environmental priorities.
Cost Considerations
Air-cooled systems generally have lower up-front costs but may be more expensive to operate over time due to lower efficiency. Water-cooled systems have higher initial costs but can offer long-term savings through reduced energy consumption.
Final Thoughts About Water-Cooled Air Conditioners
Water-cooled air conditioners offer a compelling alternative to traditional air-cooled systems, particularly for homeowners prioritizing energy efficiency and quiet operation. Their ability to transfer heat more effectively using water instead of air can lead to significant energy savings over time. However, these systems also come with challenges, including higher initial costs, more complex maintenance requirements, and the need for a reliable water supply.
Ultimately, the decision between a water-cooled and air-cooled system depends on individual circumstances. Factors such as local climate, water availability, energy costs, and personal preferences all play a role. If you are willing to invest in the initial setup and ongoing maintenance, a water-cooled air conditioner can provide efficient, quiet cooling for years to come. As with any major home improvement decision, consulting with HVAC professionals can help you make the best choice for your specific needs and situation.
Frequently Asked Questions
Do water-cooled AC units work as well as air-cooled units?
Yes, water-cooled units are actually more efficient than air-cooled units. Because water has better thermal conductivity than air, it can transfer heat more effectively using less electricity.
Can water-cooled units work in large spaces?
Yes, water-cooled units are more suitable for large buildings because of their energy efficiency and high initial price. Most homeowners don’t opt for water-cooled units because they can be expensive to install.
Do water-cooled AC units waste water?
If you use a cooling tower to recirculate te water, your water-cooled AC unit won’t waste any water. However, if you dispose of the heated water after use, then it will waste water.
How much water do water-cooled AC units use?
Water-cooled AC units need constant water flow to work effectively. For example, a one-ton water-cooled AC unit needs up to three gallons of water per minute for optimal performance.
Can I install a water-cooled AC unit in an area with water scarcity?
Unless you plan on recirculating the water by using a cooling tower, it’s not wise to install a water-cooled AC unit if you don’t have reliable access to water. Using a constant flow of water and then dumping it out will go through a lot of water quickly, which could use up your available water supply.
