Figure 1. Arctic Gator Cooling System. Source: Demandside Energy SolutionsDemandside Energy Solutions has developed and patented the novel and revolutionary Arctic Gator Cooling and Heating System (Figure 1), which combines the desirable characteristics of conventional Freon-based air conditioners together with chilled water systems.

This hybrid, compact and affordable system is suitable for residential, industrial and commercial cooling and heating. Controlled tests indicate that this system demonstrates superior performance along with significantly lower operating and maintenance costs when compared to conventional air conditioning systems. The Arctic Gator System can be installed with new systems, or it can be retrofit onto existing conventional air conditioners, resulting in a substantial cost savings.

Conventional air conditioners

Figure 2. Conventional air conditioning system. Source: Phil HipolConventional air conditioning systems use a refrigerant gas, such as Freon, that flows to a condenser unit that is usually placed outdoors (Figure 2). A compressor within the condenser increases the pressure and temperature of the refrigerant gas. At higher temperatures, heat is more readily transferred from the refrigerant to the atmosphere through the condenser heat exchanger. When the refrigerant cools, it condenses into a liquid, thereby giving off more energy. The liquid refrigerant then flows to an air-handling unit, which is usually placed indoors. An expansion valve within the air handling unit reduces the refrigerant pressure, further cooling it. The cold refrigerant then enters the evaporator heat exchanger, where warm air from inside the building is blown across it, cooling it for distribution throughout the building. The refrigerant, which has been warmed by the air, evaporates to a gaseous state by the time it exits the evaporator and returns back to the condenser where the refrigeration cycle starts over once again.

Chilled water systems

Figure 3. Chilled water system. Source: Phil HipolChilled water systems are commonly used in larger buildings where it may not be economical to use conventional Freon-based HVAC systems. These systems typically use water as the refrigerant, which flows in two closed loops: first, a condenser or refrigerant loop cools the water; second, an evaporator loop uses the chilled water to cool the air.

As shown in Figure 3, water in the chiller is compressed in the condenser and supplied to a cooling tower. The cooling tower is usually installed on the roof of a building and contains heat exchangers that are cooled by fans and water. The cooled water then returns to the chiller, where a heat exchanger transfers heat from the water in the evaporator loop to the water in the condenser loop. The chilled water in the evaporator loop is then distributed throughout the building to heat exchangers installed inside air handlers to cool the air in the building. The warmed refrigerant water is then returned to the condenser for re-cooling, and the refrigeration cycle starts over.

Assessment

Conventional and chilled water air conditioning systems each have advantages and disadvantages. Conventional Freon-based air conditioning systems have an initial low capital investment for small buildings. However, they may not be economical for larger buildings. Large buildings may require several independently controlled cooling zones that necessitate several air conditioners, each equipped with its own condenser, evaporator, air-handling unit, fans and other hardware. This would result in higher equipment costs, higher maintenance costs and increased use of electrical power and refrigerant.

Chilled water systems are more economical for large buildings, but they are complex and require a significant initial investment for capital equipment, such as the chiller unit and cooling tower. Once the equipment is in place, chilled water systems are advantageous since they require less energy for a given unit of cooling power.

For these reasons, chilled water systems are cost-justified based on the economy of scale for cooling large areas. The challenge is to implement an air conditioning system with a low initial outlay in capital equipment found in conventional air conditioner systems, together with the low operating and maintenance costs found in chilled water systems.

Arctic Gator Cooling System

The Demandside Arctic Gator Cooling System combines the advantages of conventional and chilled water systems (Figure 4). It is a hybrid system that is ideally suited for commercial, industrial and residential applications that may require several cooling zones. Rather than using the Freon refrigerant at elevated pressures to cool air within the building, it is used only to chill water inside the Arctic Gator Cooling System. The chilled water is then pumped to one or more air handling units within the building, which each cool the air. The system is controlled by a programmable logic controller, with active monitoring of power consumption and system performance metrics, such as current, voltage, pressure and temperature.

Figure 4. Arctic Gator Cooling System. Source: Phil Hipol

The Arctic Gator Cooling System provides several tangible benefits. The conventional Freon-based condenser unit is used to cool the water instead of the expensive and complex chiller and cooling tower found in traditional chilled water systems. This results in significantly lower capital equipment costs, especially if a conventional air conditioning system is already in place.

Fewer condenser units are needed since cold refrigerant is supplied only to the Arctic Gator Cooling System, which distributes chilled water among air handlers in different cooling zones. Expansion of the system will simply require adding additional chilled water feed and return lines, and an air handler and evaporator to the new cooling zone.

Since it is more efficient to transfer heat to and from water, the compressor does not need to run at high pressures or with high temperature differentials, preserving refrigerant and reducing wear and tear on the compressor machinery. This effectively reduces costs for capital equipment, refrigerant, electrical energy and maintenance.

As shown in Table 1, controlled tests indicate that for the same amount of cooling capacity, the Arctic Gator Cooling System uses fewer compressors and operates at lower pressures, temperatures and temperature differentials when compared to conventional air conditioning systems. These benefits translate into lower capital equipment costs, lower operating costs, use of less refrigerant and lower maintenance costs.

Table 1. Arctic Gator Cooling System benefits. Source: Demandside Energy Solutions

Demandside Energy Solutions

Demandside Energy Solutions has over 60 years of experience in the heating, ventilation and air conditioning (HVAC) field. They have installed and serviced numerous systems for buildings up to 100,000 ft² in size, including a full range of commercial, industrial, institutional and residential customers.

Today, Demandside Energy Solutions has reorganized for an expanded, more strategic market role in commercial HVAC design, engineering, installation and service, with ongoing technology and product development efforts, such as the Arctic Gator Cooling and Heating System.

More information about the company and their technology, products and capabilities can be found on their website.