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How They Work

“An air-source swimming pool heat pump transfers heat from the air to your swimming pool water. Air enters the unit and passes over an evaporator coil, which contains a very cold liquid refrigerant, sometimes referred to as “Freon.” As the air passes over the coil, the refrigerant heats to become warm Freon gas.

 

This warm Freon gas passes through a compressor, which compresses it to a hot Freon gas. Then, this hot Freon gas passes through a condenser or (heat exchanger), which is where the pool water enters and exits the unit. The pool water washes over the coil, heats through conduction, and leaves the unit warm. As the swimming pool water heats, the hot Freon gas cools and becomes a warm liquid refrigerant. Then, the warm liquid refrigerant passes through a metering device. Inside the metering device, pressure is reduced on the warm liquid refrigerant until it once again becomes very cold. Then the process begins again.” Efficiency The reason heat pumps are so popular is because of their energy efficiency. They use electricity to transfer heat, rather than to create heat, thus being able to produce more energy than they use. The efficiency of a swimming pool heater is measured by its Coefficient of Performance or (COP). The COP is a rating used to express the energy efficiency of air conditioners, space heaters, swimming pool heaters, and other heating and cooling devices. It measures the ratio of energy output to the energy input. The higher the COP, the higher the efficiency. The higher the efficiency, the lower the operating costs. Generally speaking, a swimming pool heat pump is the most efficient and least expensive swimming pool heating method because it has the highest COP rating. Most heat pumps have COPs that measure above 5, which means they produce over five units of energy for every unit they consume. In other words, a heat pump can provide you with over $5 of heat for every $1 of energy it consumes. It is able to produce this much energy because of its ability to transfer heat, rather than create it. AquaCal has taken energy efficiency one-step further with their top selling models, the HeatWave SuperQuiet. These units each have a COP rating of 6.0 and above (SQ110 - 6.0) (SQ120 - 6.1) (SQ155 - 6.3) (SQ175 - 6.5) A heat pump with a lower COP may cost you less initially, but it will cost you more in the long run due to higher operation costs.

 

Because heat pumps draw in heat from the surrounding environment, they work more efficiently in higher temperatures because it can easily draw heat from warmer air. In contrast, it works less efficiently in lower temperatures because there is less heat in colder air. SuperQuiet Efficiency may be the top selling feature of these heat pumps but it’s not the only one. It isn’t called the HeatWave SuperQuiet for no reason. With this model, AquaCal has revolutionized the market with a state of the art scroll compressor. Because of its quiet performance and high efficiency, this scroll compressor is one of the biggest reasons for the quiet operation of the AquaCal heat pumps. In addition to the inherent quiet operating levels of the scroll compressor design, they house the compressor in a weather proof and sound insulated cabinet within the heat pump. This not only quiets the system further but protects the compressor from wear from the weather. Another key feature of the SuperQuiet Heatwave is it’s fan assembly. Basically they have quieted the air noise by using an oversized fan assembly that rotates at, by industry standards, a very low rpm rate.

 

This slows the air flow down and consequently reduces the noise created by moving high volumes of air. Custom and high-end air conditioning systems use the same design technology to achieve silent air conditioning systems. Along with all of the above, mentioned features, these units have a corrosion proof, fade proof and impact resistant cabinet that houses the heat exchanger and compressor, this is also part of their quiet “secret” producing only 55 dB, which is virtually silent from 10 ft. away. Utilizing this SuperQuiet™ technology, AquaCal has introduced the quietest heat pump in the swimming pool industry. ThermoLink Technology The HeatWave SuperQuiet™ units also feature patented ThermoLink Titanium Heat Exchangers only found in AquaCal heat pumps. This technology is used exclusively by AquaCal and you won’t find it in any other heat pump. The reason being, heat exchangers play an extremely important role in the functionality of a heat pump.

 

They are essentially the heart of the heat pump. The primary cause of premature heat pump demise is the failure of the heat exchanger and once the heat exchanger fails, the entire heat pump is ruined. Ordinary heat exchangers are made from a cupronickel alloy. This cupronickel material is susceptible to attack from the sanitizers used in pools and spas, and from other related water chemistry conditions. The ThermoLink™ Heat Exchanger tube is made from pure titanium, and is virtually impervious to water-chemistry damage. Cupronickle is a group of copper-nickel alloys that are used in saltwater environments due to its good resistance to chemical corrosion. Because of this, Cupronickle heat exchangers became popular. These types of heat exchangers were the standard type of heat exchanger for both pools and spas for many years because at the time there was not an economical alternative with better corrosion resistance. Prior to Copronickle the industry was utilizing copper, which was not the best choice for saltwater pools because it is easily corroded which usually resulted in perforation and system failure damage.

 

Most companies eventually moved on to the Titanium heat exchangers because they are impervious to corrosion and they will not wear out or corrode. But because of its cost and need for high flow rates and increased surface area for efficient heat transfer, many manufacturers have tried to cut costs on production by only using one wrap of titanium on their heat exchangers… this has a great impact on the unit’s COP. The ThermoLink Titanium Heat Exchanger is the most durable and efficient heat exchanger in the market featuring a patented water management system that maximizes surface contact of pool water, providing superior performance over competitors. This water management system directs the water and refrigerant flow in opposite directions. This counter flow provides maximum heat transfer and minimizes pressure loss without compromising heating efficiency. It also increases BTU output while still maintaining the highest COP. These heat exchangers also add only 1 PSI at 30 GPM, which increases their compatibility with two-speed and variable speed pumps. The other great thing about the ThermoLink™ is that AquaCal gives it a lifetime Warranty.

 

With proper installation and maintenance, a heat pump will generally have a lifespan of about ten years, though many have lasted longer. We at AquaCal have seen some last as long as 15 years! All heat pumps have a limit of 104° for safety reasons. Overall, a heat pump usually requires between 24 and 72 hours to heat a swimming pool by 20°F (11°C) and between 45 and 60 minutes to heat a spa by 20°F (11°C). Other advantages of air-source heat pumps include: low operating costs, long lifespan, and small environmental footprint. Other disadvantages of air-source heat pumps include: high purchase costs and slow heating.

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