thermal solar question

Justin Topel

That is the real answer. What are you trying to do with these panels? What temperature do you desire to produce? How much space do you have for installation? How much snow do you get? I prefer flat plates for almost all conditions unless I am trying to produce super high temp. water. In my area, which can have a lot of snow, I prefer flat plates if panels especially of panels are to be mounted flush with the roof. If too much snow accumulates in the evac. tubes, they will not shed the snow very easily. Flat plates also have a long track record of great service. We regularly service systems that are 30 plus years old. I use SolarHot panels. You can find out more information at www.solarhotusa.com. They have a terrific panel that performs exceptional well. I will also always try to push for a drainback system. They will not ever freeze, if set up correctly, and I don’t worry about stagnation periods which will affect glycol systems. They also perform about 10 percent better than glycol systems. Many manufacturers of evac. tubes will state that their panels are more efficient than flat plates. That can be true at certain temps ranges. They have very little standby heat loss due to the vacuum in the tube. They become more efficient as the difference between ambient temperature and supply temperature increase. So if your are pumping really hot water on a very cold day through the tubes, you will have a higher efficiency than flat plates. In truth the manufacturers of pool collectors could state that they are the most efficient of them all and not be lying. But that case happens when they are pumping water which is close to the ambient air temperature. The closer the fluid temp is to the ambient air temp, the higher the efficiency. So the answer is quite simple…..they all are the most efficient. The answer changes when the true environmental parameters are entered. There is a gentleman who has a website that compares the two systems side by side. I am not familiar with all of the controlled parameters of this system, but I am confident that it is well thought out. Check it out at www.solarishot.com. The thing that I find interesting is that the flat plates are still slightly edging out the evac. tubes during the part of the year when evacs. should be doing better. Hope this helps.

Mister T

greenhead_2

thermal solar question

what would be the best panels for a four season climate evac or flat panel also would a closed system of drain back be better? Mark