Damage to the shingles
Because the rubberized solar mats lie directly on the roof, moisture can sit underneath the mat and without proper air circulation causing shingles to rot. This results in premature deterioration of the houses roof top. Any solar cost savings is often compromised by an early and expensive replacement of the roof. Solar vacuum tubes sit on the ground or above the shingles allowing the roof to breathe.
Plastic and sunlight never go hand in hand. Solar pool heating mats are made of plastic or rubber which by their nature quickly deteriorates in any sunlight. The average life span off a solar matt collector or plastic piping is usually 5 years or less. This greatly reduces the ROI of your solar investment. While manufactures claim life expectancies of 10 years plus, most of our solar pool customers tell us differently! Cracking and leaking are the most common problems of black mat solar pool heaters.
Black plastic by nature absorbs solar energy very well. However, it also gives off heat just as well. Have you ever touched a black painted car that has been sitting in the sun? The hot surface temperature is the result of the black paint releasing solar heat energy that it has absorbed. Solar vacuum tubes release very little heat (less than 6%). This can be verified by touching a solar vacuum tube’s surface. It will be cold to the touch even though the inside may be 300 degrees.
The heat energy that is absorbed by black solar mats is greatly diminished by wind. Wind is the number one cause of heat loss on a pool solar heater. The fact that the roof is usually windier than the ground decreases the solar pools heating efficiency even more. Solar vacuum tube pool heaters have 0 wind loss and as such are much more efficient in maximizing the solar gain.
Return on Investment
Solar pool heating with solar evacuated tubes has a payback of nearly 10 times that of plastic mats. First, the high energy output results in a system that can be ½ to ¼ the size of plastic mats. Secondly, the vacuum tubes never deteriorate in the sun and have a life expectancy of 20-25 years. With modern day mass manufacturing, a single solar pool heater with vacuum tubes (12x5) can be purchased for under $750 USD. This has the equivalent energy to a mat pool solar heater that would need up to 48 x 20 feet of roof space. SunRain Solar Pool heaters come with standalone metal stands or roof mount kits allowing greater flexibility and choice over the placement of a solar pool heater (ground or roof).