Basics, components, advantages and how to build solar pool water heaters
Swimming pool solar water heater system is one of the simplest
and the most economical applications for free sun heat usage
that does
not require high initial investment, but it provides faster payback
than most of other renewable systems.
For easy navigation use the links below to learn more about how to heat
water for your swimming pool.
Solar pool water heater system is the right choice if planning to
use and heat the swimming pool in and off the season
(extended swim season), where free sun
energy is used to increase the temperature in the pool.
Keep in mind that unheated pool will have the temperature a little
above the outdoor temperature (if located in the southern warmer
regions).
Swimming
pool solar water heater has to be properly sized and provide
desired temperature. If not than the backup boiler has to be used.
Picture is courtesy of energysavers.gov
The most popular pool solar heating system is where the solar panel
is made of black PP plastic, rigid or with the individual pipes and
usually roof mounted. Water is inside the collectors only when
it
circulates through. This is why
this
system is called the drainback system, as seen in domestic solar
water heating. This is helpful in the winter time so chances of water
freezing inside the solar panel and pipes are significantly reduced.
Swimming
Pool Solar Water Heater Advantages
The main advantages of the solar water heater for pools are the
required temperature, which is lower than for domestic hot water
production, and the absence of the separate storage tank.
Here are other reasons why to buy and install swimming pool solar water heater
system:
Low initial cost.
Low annual operating costs.
Easy to install.
Solar pool heating systems are efficient and durable.
Maintenance free systems.
Faster payback.
Long lifespan.
Swimming
Pool Solar Water Heater Parts
The main components of the swimming pool solar water heater system are:
Collectors or panels
The pump
The filter
Controllers (i.e. to compare incoming and outgoing
water temperature).
Fittings
Valves
Pool solar collector is probably the most important part
in the heating system. Solar
collectors are usually roof mounted and designed to heat large amounts
of water to relatively low temperatures, which is between 80 and
90 F.
This is achievable due to the material used, which is polypropylene.
This cheap material allows pool solar water heater to be affordable
over expensive version with copper tubes. Another reason to
achieve "low" water pool temperature is its unglazed setup.
The
problem with the unglazed or uninsulated collectors is the collector
incapability to produce any heat during the winter time.
Due to
the limited operating temperature, which is usually between 220 and 240
F, polypropylene solar collectors cannot be installed inside the glazed
box to increase the efficiency as the manufacturer will void the
warranty.
Standard
sizes for pool collectors are 4 feet wide and 8, 10 and 12 feet in
length.
Top and bottom tubes are called header tubes with the size of 1,5 or 2"
connected with the risers, 1/4" in diameter. Solar panel is through
the headers connected to the PVC pipes by the rubber couplings and hose
metal clamps.
Pool's filtration pump is used to
transfer the pool water to the solar panels where it is heated by the
sun radiation and then returned to the pool. Before the water goes to
the solar collector, it has to go first through the filter. On its way
back to the pool, it will usually go through the backup heater
and the chlorinator if they are used.
As this heating system is drainback system, when pump is turned off,
water from the collectors drains down to the pool.
Build
Swimming Pool Solar Water Heater Tips
If you are handy at plumbing and electrical wiring, it
is very easy to build and/or install swimming pool solar water heater.
Simply
buy the solar
water heater kit and the rest is like a puzzle. Use the glue and hose
clamps to put the system together.
How will you determine the size of
the solar panel... total length of the panel should cover 50% of the
pool's surface area (for example if the pool covers 600 sq.ft collector
should be at least 300 sq. ft). This rough calculation assumes the
southern warmer
regions (Florida, Texas), if the panel is properly oriented and if
there are no shaded
parts in the pool. Otherwise you have to increase the exposed area of
the solar panel.
When building a solar collector recommendation is to use the
above PP tubes, black flexible rubber mat, arrays of black plastic pipe
or tube-on-sheet panels made of copper or aluminum. These collectors
are called flat-plate collectors that feature large diameter headers
and many small tubes between them.
Install
the solar collectors so they will face south and tilted at an angle
equal to the latitude of the pool's location minus 15 degrees.
Cost
of the Swimming Pool Solar Water Heater
To buy a DIY solar water heater kit, size of 300-400 sq. ft., expect to
pay from $1500 to $2500 that depends on complexity of
your system and the pool size. But if you want someone else to install
it
for you, it will cost you double. Warranty from the manufacturer is
usually 10-15 years, which depends on the quality of the UV screening
materials (inhibitors) and predicted payback period is 2-7 years.
Swimming
Pool Solar Water Heater - Tips to Save
Most of the heat loss, which is over 70%, from a swimming pool is
caused by evaporation of water from the surface.
Warm water evaporates more rapidly than cool. To reduce the heat
loss during the evaporation, buy a good quality pool
cover and save.
The heat loss is directly proportionate to wind velocities, pool
temperature, humidity and air temperature. The most important factor is
to have the swimming pool installed in a sunny spot as more than 75% of
the solar energy is absorbed by the pool water.
Keep in mind to properly size your swimming
pool solar water heater so the heating system can have the minimum of
the heat loss and maximum heat gain. Take into account the location of
the swimming pool, shades, winds, and is the panel oriented to the
south.
Homemade
solar pool water heaters examples
Andy made this DIY solar pool heater from 100 ft coils of half
inch plastic pipe
for the pool size 30 feet x 12 feet x 4 feet average depth and
11,000 gallons. Solar panels are installed on the roof and due to the
roof layout are facing east. This panel was built 5 years ago
and the cost to build was around $300 for tubing and PVC but the
framing materials came from scrap... more
Another simple homemade pool solar water heater made by Fraser located
somewhere in Spain. He built the heater for 70 Euros for the pool size
of 60m3 and 1m3 insulated hot tub while keeping the temperature of 35 C
year round... more
How to build a solar pool water heater from instructables.