| Pool heating |
Pool HeatingSolar Swimming Pool Heaters You can significantly reduce swimming pool heating costs by installing a solar pool heater. They're cost competitive with both gas and heat pump pool heaters, and they have very low annual operating costs. Actually, solar pool heating is the most cost-effective use of solar energy in many climates. How They Work Most solar pool heating systems include the following:
Pool water is pumped through the filter and then through the solar collector(s), where it is heated before it is returned to the pool. In hot climates, the collector(s) can also be used to cool the pool during peak summer months by circulating the water through the collector(s) at night. Some systems include sensors and an automatic or manual valve to divert water through the collector(s) when the collector temperature is sufficiently greater than the pool temperature. When the collector temperature is similar to the pool temperature, filtered water simply bypasses the collector(s) and is returned to the pool. Solar pool collectors are made out of different materials. The type you'll need depends on your climate and how you intend to use the collector. If you'll only be using your pool when temperatures are above freezing, then you'll probably only need an unglazed collector system. Unglazed collectors don't include a glass covering (glazing). They are generally made of heavy-duty rubber or plastic treated with an ultraviolet (UV) light inhibitor to extend the life of the panels. Because of their inexpensive parts and simple design, unglazed collectors are usually less expensive than glazed collectors. These unglazed systems can even work for indoor pools in cold climates if the system is designed to drain back to the pool when not in use. Even if you have to shut the system down during cold weather, unglazed collectors may be more cost effective than installing a more expensive glazed collector system.
Glazed collector systems are generally made of copper tubing on an aluminum plate with an iron-tempered glass covering, which increases their cost. In colder weather, glazed collector systems—with heat exchangers and transfer fluids—capture solar heat more efficiently than unglazed systems. Therefore, they can be used year-round in many climates. Glazed collectors also can be used to heat domestic hot water year-round. Both glazed and unglazed collector systems should include freeze protection if they'll be used in colder conditions. Selecting a Solar Pool Heater A solar pool heating system usually provides a payback of between 1.5 and 7 years, depending on your local fuel costs. They also typically last longer than gas and heat pump pool heaters. Your actual cost and payback depend on many factors. Therefore, before you purchase and install a solar pool heating system, you should do the following:
Installation and Maintenance The proper installation of a solar pool heating system depends on many factors. These factors include solar resource, climate, local building code requirements, and safety issues. Therefore, it's best to have a qualified solar thermal systems contractor install your system. After installation, properly maintaining your system will keep it running smoothly for 10–20 years. Consult your contractor and read your owner's manual for maintenance requirements. Your collector should require little maintenance if the pool's chemical balance and filtering system are checked regularly. Glazed collectors may need to be cleaned in dry climates where rainwater doesn't provide a natural rinse. Gas Swimming Pool Heaters Gas-fired pool heaters remain the most popular system for heating swimming pools. Today you can find new gas-fired heater models with much higher efficiencies than older models. Still, depending on your climate and pool use, they may not be the most energy-efficient option when compared to heat pump and solar pool heaters. How They Work
They're most efficient when heating pools for short periods of time, and they're ideal for quickly heating pools. Therefore, gas pool heaters can be a good choice for pools that aren't used on a regular basis. Unlike heat pump and solar pool heaters, gas pool heaters can maintain any desired temperature regardless of the weather or climate. Selecting a Gas Pool Heater When selecting a gas swimming pool heater, you need to consider the following:
Installation and Maintenance Proper installation and maintenance of your gas pool heater can optimize its efficiency. It's best to have a qualified pool professional install the heater and even perform complicated maintenance or repair tasks. Read your owner's manual for a maintenance schedule and/or recommendations. You'll probably need to tune up your pool heater annually. Also, scaling in the burner or heat exchanger may decrease efficiency over a period of time. With proper installation and maintenance, gas pool heaters typically last five or more years. Heat Pump Swimming Pool Heaters
If you want an energy-efficient way to heat your swimming pool, consider using a heat pump pool heater. Heat pumps use electricity to capture heat and move it from one place to another. They don't generate heat. As the pool pump circulates the swimming pool's water, the water drawn from the pool passes through a filter and the heat pump heater. The heat pump heater has a fan that draws in the outside air and directs it over the evaporator coil. Liquid refrigerant within the evaporator coil absorbs the heat from the outside air and becomes a gas. The warm gas in the coil then passes through the compressor. The compressor increases the heat, creating a very hot gas that then passes through the condenser. The condenser transfers the heat from the hot gas to the cooler pool water circulating through the heater. The heated water then returns to the pool. The hot gas, as it flows through the condenser coil, returns to liquid form and back to the evaporator, where the whole process begins again.
Higher efficiency heat pump pool heaters usually use scroll compressors versus the reciprocal compressors of standard units. Heat pump pool heaters work efficiently as long as the outside temperature remains above the 45ºF–50ºF range. The cooler the outside air they draw in, the more energy they use. However, since most people use outdoor swimming pools during warm and mild weather, this usually isn't an issue. Heat pump pool heaters cost more than gas pool heaters, but they typically have much lower annual operating costs because of their higher efficiencies. With proper maintenance, heat pump pool heaters typically last longer than gas pool heaters. Therefore, you'll save more money in the long run. When selecting a heat pump pool heater, you should consider its:
Installation and Maintenance Proper installation and maintenance of your heat pump pool heater can optimize its efficiency. It's best to have a qualified pool professional install the heater, especially the electric hookup, and perform complicated maintenance or repair tasks. Read your owner's manual for a maintenance schedule and/or recommendations. You'll probably need to tune up your pool heater annually. Because of a heat pump pool heater's many moving and electrical parts, it will probably require periodic service by an air conditioning technician. With proper installation and maintenance, heat pump pool heaters can last 10 or more years.
Using a good pool cover is the most effective thing you can do to save pool heating costs and reduce greenhouse gas emissions. All of the other pool heating methods discussed in this article should only he used in conjunction with a pool cover. Not to do so would be like running your house air conditioner during August with the doors and windows open. The system will still work, but the operating cost will be as much as three times higher. |
Example of a solar pool heating system. This diagram shows the path pool water would travel as it goes through a solar pool heating system. The water exiting the pool goes through a strainer, then is pumped through a filter, through the collector, through a conventional pool heater (if you have one), and back into the pool. This system also includes a check valve, a flow control valve, and temperature sensors.
An illustration of a solar panel. A tube is at each end of the panel, and arrows show the flow going through one tube, across the panel, and out the end of the other tube, which is labeled the header/manifold.
Illustration of a gas pool heater. The heater is a large cube with horizontal vents down the two sides showing. Each of these sides also has a small panel with two round dials.Gas pool heaters use either natural gas or propane. As the pump circulates the pool's water, the water drawn from the pool passes through a filter and then to the heater. The gas burns in the heater's combustion chamber, generating heat that transfers to the water that's returned to the pool.
Illustration of a heat pump. The heat pump is a large box covered on all sides. On the back is the evaporator coil, which looks like a grill. On one side are two pipes that allow water to flow in and out of the heat pump.
An illustration showing how a heat pump operates.
Pool Cover - A must