Heat pump systems

by Sally Bouorm | March 1, 2012 8:43 am

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By Jason Cramp

The high cost for non-renewable energy sources, such as oil and natural gas, continues to rise each year. As this is top of mind for most consumers, an increasing number are looking for alternative heating systems that maximize energy output while reducing the amount of energy required for operation.

When it comes to heating a swimming pool, this appliance is the heat pump. Depending on the unit’s size, no more than 6.5 kW of electricity is required to operate the evaporator fan and compressor—the system’s two main components—making heat pumps an environmentally friendly, reliable and highly efficient method to heat swimming pool water.

How do they work?

Heat pumps are designed to capture and transfer heat energy using refrigerant technology. Air circulates through the system’s evaporator air coil where a liquid refrigerant absorbs heat from the ambient air, collecting energy as latent heat of evaporation (i.e., the energy used to change liquid to vapour). This vapour is then pumped into the heater’s compressor where its temperature increases significantly before being pumped into the heat exchanger condenser. Heat is then transferred to the water as it travels through the heat exchanger. Once this process is complete, the refrigerant returns to a liquid state and starts over again.

2010: A year of change

On Jan. 1, 2010, as part of the Montreal Protocol on Substances that Deplete the Ozone Layer, no new heating ventilation and air conditioning (HVAC) equipment using R-22 (chlorodifluoromethane or difluoromonochloromethane) gas could be manufactured or imported in Canada and the United States.

Some experts consider R-22, the refrigerant most commonly used in heat pump equipment, to be a contributing factor in the depletion of the ozone layer. According to studies, it contains elements that react with the ozone layer when the refrigerant breaks down in the atmosphere. To abide by the regulations set out in the Montreal Protocol, R-410A, which is a mixture of difluoromethane (CH₂F₂ [R-32]) and pentafluroethane (CHF₂CF₂ [R-125]), is now the preferred refrigerant being used in HVAC equipment, including swimming pool heat pumps, as it does not contribute to ozone depletion.

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According to Graham Bishop, president of Titan Systems, which manufactures Titan and Omega heat pumps in Coburg, Ont., fine tuning heat pump designs for the new R-410A refrigerant to maximize energy-efficiency and noise reduction are the two main innovative fronts most manufacturers are concentrating on.

“With new, swept-wing fan blade designs, electronic modulating valves, variable-speed fans and compressor motors, design engineers have a host of new technologies to incorporate in the coming years,” says Bishop. “This will only further reduce the cost for pool owners who wish to maintain a heated pool.”

With these innovations in mind, Titan has found their 80,000 and 100,000 British thermal unit (Btu) models to be the most popular with pool owners and dealers alike as they can be recommended for a vast majority of pool sizes.

Also adding to their popularity is the fact that all Titan heat pumps (for inground pools) come standard with 50 mm (2 in.) water connections to complement today’s energy-efficient water hydraulic pool designs.

“Our proprietary heat exchanger has virtually no pressure drop, which further enhances the overall efficiency of the pool’s hydraulic design,” Bishop adds. “Further, our unique control board offers a built-in timer to control the circulating pump, as well as the heat pump, for those pool owners who wish to take advantage of time-of-day hydro savings without going to the expense of full automated control.”

Size, power and design

Pentair Water Pool and Spa, a manufacturer of heat pumps in Sanford, N.C., has also focused on efficiency by designing systems that generate more Btus with smaller footprints. For instance, the company’s newest UltraTemp heat pump models have smaller frames and provide just under 100,000 Btus, while the company’s most popular systems are its mid- to high-range Btu models, which generate between 110,000 to 120,000 Btus.

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“Other than capacity differences, another key advantage to our heat pumps is our digital control board, which has a two-line readout with RS-485 (a digital communications network standard) communication hookup to our automation systems,” explains John Vasarhelyi, Pentair’s heat pump products manager. “All of our heat pumps offer this two-line communication cable attachment for easy integration with pool/spa controls.”

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Another key feature of the company’s heat pump line is it warranty and service, he adds. “We offer a full two- or three-year warranty (depending on the model), along with a 10-year warranty on the compressor and lifetime warranty on the titanium heat exchanger,” says Vasarhelyi.

Another manufacturer that stands behind its heat pump product line is Nirvana Chauffe-Piscine Inc., in Grand Mere, Que. According to the company’s Michel Lesage, Nirvana offers a three-year warranty on parts and labour and five years on the compressor. Titanium coils have a 10-year limited warranty, while heater cabinets have a 15-year limited warranty.

Further, its heat pumps are designed with Canada’s northern climate in mind as their performance at low temperatures (Heating Season Performance Factor [HSPF]) provides a high co-efficient of performance (COP). For example, a COP of five will generate $5 worth of heat from $1 worth of electricity.

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Nirvana also invested in research and development to find noise reduction solutions, resulting in a heat pump that produces less than 60 decibels. This was accomplished by using sound insulation on the compressor’s cover and a fan blade design that is more efficient and produces less noise.

Hayward Pool Products Canada, which manufactures the HeatPro line in Oakville, Ont., is another company that has focused on design and noise reduction. For instance, the HeatPro’s round base provides a compact footprint, which allows for easier installation, and makes them ideal for retrofit replacements. The heater is available in 65,000, 85,000, 110,000 and 140,000 Btu models, each measuring only 794 mm (31.25 in.) wide and 1,016 mm (40 in.) tall.

The line also uses noise-reduction technology, such as a profiled fan blade design for improved airflow and quiet operation, while an acoustic compressor cover further reduces sound levels.

Cold climate operation

In some climates, depending on the outside temperature and humidity levels, frost can form on the outside of the coil—during heat pump operation—and interfere with the unit’s ability to generate and transfer heat. As such, most heat pumps available today offer an automated defrost cycle, which melts any ice formation to ensure the heat pump operates efficiently.

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According to Simon Nadeau, CEO of Waterco Canada, which manufactures the ‘Geyser’ and ‘Aquaflow’ heat pumps in St. Hyacinthe, Que., the company has offered units with this feature for the last decade on its high-end models; however, it is now a standard feature on all of the company’s heat pump products.

“The defrost feature works automatically,” explains Nadeau. “During this cycle, the fan and compressor stop and start again in reverse cycle to push the hot refrigerant through the evaporator to melt the frost. Then, the compressor stops to allow the system to dry and reverts back to its normal operation. This cycle takes no more than five minutes to complete.

“This feature allows pool owners to heat their pool water during lower ambient air temperatures, as well as minimize heat loss from the pool by minimizing heater downtime.”

Another feature that sets Waterco’s heat pump line apart from others on the market is their heat exchanger. According to Nadeau, its compact design, internal water circulation guide, which is compatible with chlorine generators and increased water turbulence and velocity, provides improved thermal exchange and energetic yield.

Commercial market expands

In the past year, the heat pump industry has also seen increased focus on the commercial market with heavy-duty product lines and features. With this in mind, the latest heat pump products offered by Rheem Canada Ltd., which manufactures the new Raypak Professional Series and Rheem Compact Series in Brampton, Ont., cater to this market segment.

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The Professional Series is designed for use in most commercial applications such as hotels and resorts, in addition to high-end residential pools, while the Compact Series offers the same features as the company’s Classic Series residential heat pump line; however, geared more towards the Canadian market.

“Professional Series units come with a flow switch (instead of a simple pressure switch), commercial-grade refrigerant components and our new low-noise, swept-wing fan blade assembly,” says Tom ‘TJ’ Redman II, Rheem’s heat pump product specialist. “These units come encased in our new stainless steel cabinet and are currently available in 170,000 Btus, with more sizes to be available soon.

“The Classic Series is available in 48,000, 67,000 and 85,000 Btu models. Regardless of the size selected, these units are packaged in our new compact shell, where even the largest model measures less than 800 mm (31.5 in.) wide and 900 mm (35.4 in.) tall.”

All Rheem and Raypak heat pumps are equipped with plumbing and electrical connections designed with quick and convenient connection in mind, along with component access and refrigerant ports with the service technician in mind.

Heat pump selling features

When selling heat pumps it is important for consumers to understand they must operate continuously to maintain the desired water temperature. Therefore, they cannot be operated like a gas heater to raise water temperature on demand.

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With this in mind, heat pumps should be sold based on performance, reliability and low-operating costs. Their ease of automation should also be emphasized, as today’s heat pumps offer sophisticated control systems, which makes maintaining a heated pool easier.

For instance, Jandy’s heat pumps by Zodiac Pool Systems Canada Inc., in Oakville, Ont., allow pool owners to monitor heat pump functions from wherever is most convenient.

Further, the line’s advanced control options offer programmable features for both pools and spas, self-diagnostics and multilingual capability, while its ‘auto-heat’ feature maintains the water temperature automatically and efficiently, 24-7.

Source URL: https://www.poolspamarketing.com/trade/heat-pump-systems/

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