The differences between solar heating for domestic use (showers, cooking) and solar pool heating
The solar water heater (also known as flat plate collector) can be found in many households around the world. It is responsible for heating the water consumed daily by residents. We are frequently asked by our customers what are the main differences between the solar water heater for domestic water and the solar pool heating systems we manufacture at Magen eco-Energy? The principal of both systems is in fact identical. Both collectors are solar thermal collectors which convert sunlight into heat for the purpose of water heating. That being said, the materials and heating processes are different as well as the use of the heated water. In the following article we will explain these differences.
The solar water heater is comprised of two major components - the water vessel (which collects the heated water) and the solar collector (flat plate collector). The solar collector is dark in color, therefore is naturally heated by the sun. The material it is made of - usually galvanized tin, copper or aluminum is a good heat conduction material. The water flowing inside the piping in the collector is surrounded by very hot air and therefore is heated by it. The water vessel is installed higher than the collector so hot water rises into the water vessel by a process called 'natural convection', while the cold water flows to the solar collector until all the water is heated. The water heater usually comes with an electrical backup system for cloudy days when there is no sufficient sunlight to heat the water, as well as a thermostat which is responsible for stopping the heating process when water is sufficiently heated to 65°C/149°F.
The main difference between the two systems is that the solar water heater is designed to withstand high temperature and pressures for small amounts of water at low capacity. Whereas the solar pool heating collector heats large quantities of water at high capacity to low temperatures of 28-32°C/82-90°F.
How does the solar pool heating system work?
The system is comprised of four main elements - the solar collectors, the pool's circulation pump, piping and solar controller. The circulation pump pumps water from the pool through the filter to the solar panels. Water enters the individual riser tube of the solar collector from the bottom. The sun, heats the water as it flows through the collector towards the top before it is returned to the pool. The controller of the system is hooked up to two sensors: one samples the pools water temperature while the other samples the ambient temperature next to the solar collectors. This is how the system identifies if pool water requires heating or is sufficiently heated and if ambient conditions are optimal to heat water and determines whether to circulate pool water through the collectors or not. The solar pool heating system can last as long as 25 years, is backed up by the longest and most comprehensive warranty in the industry and can withstand the most extreme weather conditions.
Our polymeric solar pool heating collectors have proven as the most cost effective pre-heating system (showers, kitchens, laundry) for commercial and public facilities. It can be concluded that for hotels, country or sports clubs pre-heating systems are more beneficial than domestic hot water systems, as the later heat smaller quantities of water, wear out quicker and consume more energy (therefore more money). Commercial facilities that already have a solar pool heating system installed, can utilize that system to pre-heat the shower and laundry water using renewable energy, before transferring them to the electrical, or gas system for additional heating at a higher energy cost. This enables quick ROI, drastic energy savings and enjoying a low maintenance system which is robust, durable and resistant to chemicals, corrosion and scale build up.