Warming up a Pool with Solar Power

Pool covers represent the most economic solution to reduce heat loss, excessive water evaporation and the use of chemical products for maintenance.

* The area required for the solar collector varies between 50 and 100% of the surface of the pool. The variables that determine their size are: efficiency of the solar collector, location (orientation, wind) and the preferences of the owner.

* Ideally, the collector look south (north) and have an inclination from the horizontal of about 20 to 32 degrees.

* Swimming pools (pools) installed inside the house for use throughout the year, need solar collectors closed flat, covered with glass and must have a pitch between 35 and 45 degrees.

* Ventilation tubes that emerge from the roof installation can encounter problems when they want to locate this type of solar collectors on the roof.

* Whether by bad orientation or because the surface of the roof is not enough, it can force the installation of solar collectors to a level ground, using a framework of support that is located near the swimming pool.

* Most of the commercial solar collectors require to be completely drained when it's winter, to avoid freezing problems.

* All the plumbing should be designed to drain the pool when the system is not in use. Sometimes it is required that there is a manual draining system, which is activated with the change of season.

* Paint al of the PVC pipes, to protect them from UV rays.

* If the pump system is not enough, it may need additional pumps.

* To avoid the use of automatic high cost systems it is best to use the manual systems or the use of an activation clock.

* Isolate the solar system using bypass valves, when you have to clean the filter reverting the circulation (backflush).

Efficiency of a solar system

The warming of a swimming pool is one of the most economical applications of solar energy. Its use not only allows the extension of the period of use, but it helps to improve control of its temperature and, in some cases, do not increase the cost.

Let's start with the beginning - Reducing the Power Losses

The most basic and practical step to extend the period of use of the pool is to cover it. Up to 70% of heat supplied to a pool is lost by evaporation. If this loss is added to the radiation and convection, the idea of heating a swimming pool without using a deck appears to be similar to that of heating a house with all the doors and windows open. While it is inconvenient to put on and take off the cover, it not only helps to extend the season of use, but keeps it cleaner and reduces the use of chemicals used in maintenance.
If the cover is transparent, the sun will help to warm it up. The plastic covers have a cost of around 30 to 40 cents per square foot and last between 2 and 5 years.

How a  Solar Powered System  Works

The plumbing required by the solar system adapts to the existing ones, including the filter. During the day, when the filter is in operation, water passes through the collector before being returned to the pool. If you add an automatic system, you must add a central control, due to sensors of the system, which will act on two valves on the line, to send the water to the panels or the water to the pool.  Without extra control, the owner must operate the valves.

Designing the System

To determine the number of collectors it is necessary to consider several factors. The most important is the surface of the pool. The design begins considering a collection area equal to 50% of that area. This value is corrected, considering the wind speed, the shade of the pool, the temperature and humidity rise and the end of season that is preferred. It is not unusual to end up with an collection area which represents 100% of the surface of the pool.

Guidance

Ideally, as always, the solar collectors should look to the south and have an inclination of about 10 to 15 degrees from the horizontal. If this can’t be done or is compelled to point them towards the west, increase the surface a 75%. Another type of guidance is not recommended.

While the most common is the installation of the panels on the roof, sometimes the distance, orientation or aesthetic reasons dictate the use of a construction assistant support for them, "at ground level." If the winters are days of low temperature, it is essential to drain the system to prevent freezing water.

Temperature

A solar system for heating swimming pools work with a high volume of movement, so that the water at the outlet is just 2 to 3 ° F degrees above the input.

Costs of heating a pool with solar energy (solar power)

Depending on how many collectors are needed and the length and complexity of the plumbing, we can estimate a cost of between $ 2,000 and $ 4,000 dollars.

Collectors

The regular collectors for this application is made of plastic, which has a large diameter tube top that connect to a large number of very small diameter tubes, which will gather again in another tube equal to the top one. These solar collectors will tie to the ceiling in the top, middle and bottom.