Solar Water Heating Collectors
There are two types of collectors for solar water heating, the first is a flat plate solar collector, the second is a solar vacuum or evacuated tube collector. Both types have their advantages and should be chosen based on the type of solar water heating application you are using them for.
Flat Plate Solar Water Heater
These units have been around for the longest time and continue to be popular in warmer regions that don’t experience significant amount of cold. Our flat plate collectors use a layer of borosilicate glass that is very low in iron. This allows maximum sun penetration. Internally there is a series of copper pipes that are fused onto an internal plate of aluminum that is coated with a patented special selective coating. Unlike others flat plate panels this selective coating advance properties allows it to absorb nearly 98% of the sun’s radiation.
The heat from the sun is then transferred to the copper pipes and absorbed by our special solar high temperature glycol and circulated to the heating load such as hot water or space heating or pools via a heat exchanger.
Solar Vacuum Tubes
These modern-day solar water heating collectors take advantage of the same technology used by NASA. The vacuum tube with its internal heat pipe can absorb solar heat energy in temperatures as low as -40. These types of solar collectors are used mostly for space heating or solar heating in regions that experience colder, below freezing winters.
A solar vacuum tube works in a similar fashion our flat plat solar collectors except the tubes themselves are within a vacuum. This means that there is virtually no heat loss once the sun is absorbed. In fact, the glass tubes will remain frosty even though the interior heat pipe can reach temperatures of as high as 480 F. By using a copper heat pipe tube in the center, the energy is transferred to the top bulb of the heat pipe and then to a sealed copper header where it heats up the solar heating fluid.
Where are these used?
As mentioned, both solar water heaters have their place. Flat plate collectors are ideal in southern USA and the Caribbean. They are great for economical solar domestic hot water heating and can save an average home 60-80% on domestic hot water. They are also great for seasonal solar pool heating and have many advantages versus traditional plastic mats used on most pool.
Solar vacuum tubes are turbo charged and can be used in space heating applications such as radiant floor heating, fan coils and air handlers. These solar water heaters are ideal for Northern regions or in industrial applications such as agriculture and process heating where large volumes of hot water heating are required. Hotels, Car Washes, Care Homes are all great examples where solar vacuum tubes can save significant operating costs.
Closed loop designs
All our solar thermal heaters are based on closed loop designs. A closed loop design isolates the system from any outside oxygen and as such does not need any maintenance as there is no internal oxidation that can lead to corrosion and fouling. A closed loop system is the same type of system that is used in a boiler loop or domestic radiant floor heating. In order to freeze protect the heating fluid in colder climates, special high temperature glycol is used that is a capable of handling the high temperatures that can be found in a solar water heater.
We use the most advance solar thermal controllers and pump stations. RESol controllers and pump stations are made in Germany and have been proven in over 10,000,000 solar thermal systems worldwide. Advanced features such as freeze protection, holiday mode, system protection, and remote monitoring are all standard feature that ensure the solar water heater will perform under any condition.