Heating pool & spa water

by Sally Bouorm | April 1, 2011 2:09 pm

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By Gene Brown

When it comes to pool heaters, one size definitely does not fit all. With so many variables on every job site and different customer needs and preferences with every project, choosing the right heater requires a lot of consideration.

Talking to the client

In order to find the right heater for the project, builders need to talk with clients about a variety of factors.

Preferences

What the client asks for is not always best suited to their situation. By asking this question, the builder has the opportunity to educate the client about their options and help them make an informed decision. If the customer is concerned about the environment, they might opt for a more ‘green’ heater selection—and steer clear of options such as fossil fuel heaters.

Expectations

What does the customer expect in terms of heater performance and ability? Is this project a pool and spa combo with mixed water, filter and heater systems? These combinations work well for chemical treatment but require a fast recovery time. One must also determine what type of heater will best fulfil the overall swimming needs of the customer? For example, an air/water heat pump is very efficient, but also has a tendency to be seasonal and require a large electrical hook up. If the client plans to use their pool all year, a fossil fuel heater may be the best option.

Site conditions

There may be location conditions that influence heater selection. For example, the job site might not have natural gas or an existing power supply that is already maxed out. These situations will definitely influence the client’s decision. If the pool is in a sunny location with a dark deck, a radiant-heat system could be installed in the decking and used as a form of solar energy to cool the deck and heat the pool. A pool cover can also be an influencing factor, as can insulation (of either the pool, plumbing or both).

There are many benefits to covering pools. The main benefit is minimizing heat loss due to evaporation, while other fringe benefits include cleanliness and lower chemical usage.

Budget

A builder must also determine what the customer’s budget is and whether there is room for negotiation. Some clients may be inclined to choose a heater with fewer upfront costs, only to change their minds when long-term savings (e.g. monthly operational expenses) are added to the cost equation.

An array of options

Once the aforementioned information has been gathered, it is time to narrow the client’s options. With so many choices, it is important for builders to understand the pros and cons of each, and be able to relate that information to their clients.

Fossil fuel (natural gas or propane)

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Fossil fuel heaters are generally very quick in providing on-demand heat and are inexpensive to install the gas and venting connections. These systems are a common mid-range efficiency pool heater that is one of the lower priced units on the market today. However, they can be more expensive to operate (increasing cost of gas), have higher emissions and must run at higher temperature ranges for optimal performance.

As they are mid-range efficiency class heaters, the output of gas and emissions is something that should be discussed with the customer. The other thing to consider is when running pool water temperatures below 15.5 C (60 F), with colder outside temperatures, it is hard on a gas heaters, as they condensate from the temperature difference in the heat exchanger. Condensate then drips onto the burner causing premature failure. Therefore, these heaters are not intended to run lower temperatures for extended periods of time.

Electric

There are a few pros to using an electric heater. Generally, they are inexpensive to operate and create no emissions on site. They can also run at various temperatures without causing damage to the heater. On the other hand, electric heaters place a significant demand on the household electrical supply and require an expensive initial installation.

Often the case with new and/or existing homes, the main electrical panel is not large enough to provide the amperage needed to run an electric heater without the need to install additional amperage. Wiring sizes and potential electrical upgrades can make electric heater installation become expensive.

Air/water heat pumps

Heat pumps are efficient and heat pool water inexpensively. These systems draw in outside air, which is passed over an evaporator coil containing a liquid refrigerant. As heat is absorbed, the liquid turns to gas, which then passes through the compressor and condenser where heat is transferred to the cooler pool water circulating through the heater.

Heat pumps, however, are more expensive than standard heaters and have higher electrical demands. They can also take more time to initially heat the pool depending on the ambient outside air temperature (i.e. when the weather is cold, the heat pump does not work as well).

Geothermal

Geothermal heating systems are efficient, can be used year-round and are an environmentally conscious choice, as they draw heat from underground or water to water, via heat exchangers and transfers it to the pool.

During the summer, when the house is being cooled, geothermal systems also allow the heat extracted from the home to be dumped into the pool to heat the water. Usually these systems do not have a carbon footprint and have a very high return on investment (ROI) with regards to the electricity used to operate the system versus the heat generated.

Due to the high costs involved in retrofitting an older home, geothermal heating systems are mainly used in new home construction.

Solar

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This is another environmentally conscious choice; once installed, a solar heating system provides ‘free,’ clean energy. There are also several different systems to fit different budgets. Typical, unglazed solar panel systems are manufactured of heavy-duty rubber or plastic and comprise tubes or mats that are installed on the roof to collect heat from the sun to transfer it to the pool water circulating through the system. Glazed solar panels work much the same way; however, they are manufactured of copper tubing on an aluminum plate with a glass covering. This increases the system’s cost, however, glazed solar panels are able to capture heat year-round, regardless of weather conditions. That said, a high-quality system is expensive and the pay back will likely take many years.

Heat exchangers/radiant heaters

Both of these systems have a heat source driving them (e.g. fossil fuel, geothermal, etc.), but also allow the use of a boiler system to produce heat. Heat exchangers will typically transfer heat quickly, but can be influenced by out-of-balance water chemistry, such as low or high alkalinity or over chlorination, as with most heating systems.

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Radiant heaters are slower to heat; however, they are sealed and not subject to pool water imbalance issues. This heating system comprises tubes installed in the pool floor and/or walls and never comes in contact with the pool water like other heating systems. With this heating system, it is possible the heater or an element may never need to be changed.

There are more pros and cons to various heating systems than can be mentioned in this article. In all projects, the builder must do his or her own due diligence to find the heating system best suited to the site and client. By researching all possible options and keeping an open mind about potential solutions, builders can offer their clients the perfect recommendation.

CASE STUDY: BOWEN ISLAND

[5]This is a pool and hot tub combination in which both elements are covered and have underground insulation. The pool is a perimeter overflow vanishing edge. Being located on an island meant the cost of electricity and propane was very expensive; there was no natural gas source. The client ultimately decided to go with a high-end solar system as the primary heating source, backed up with a high-efficiency boiler and heat exchangers. This combination improves the efficiency and reduces environmental impact while still producing heat on demand when needed. The system is also automated, allowing the client to turn on the heater from his cell phone while driving home.

 

Gene Brown is a second-generation pool builder in British Columbia’s Okanagan Valley. He is the president of Valley Pool & Spa, a swimming pool design/build firm based in Kelowna, B.C. He can be reached at genebrown@valleypoolandspa.com[6] or by visiting www.valleypoolandspa.com[7].

Source URL: https://www.poolspamarketing.com/trade/heating-pool-spa-water/

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