Like any expensive equipment containing lots of metal and liquid, a solar thermal collector array needs to be grounded. Collectors can act like huge static electricity absorbers, gathering charge from nearby lightning strikes and passing it along all the copper pipes to the controller (in an AC system). One big power surge and your controller goes pop!
If you're new to plumbing, you will want to practice soldering pipes before you try your skills on an actual solar thermal installation. It's not difficult but it's extremely important to do the job well or you'll get leaks and other problems. Practice makes perfect!
Like most questions in the solar thermal arena, the choice of an AC or DC system is subjective, depending on your needs and your system type. Let's start with the unavoidable limitations:
Although the collectors are installed, the tank in place, the heat exchanger piped in and the plumbing done, there is no guarantee that your solar thermal system has no leaks. You need to test it before you fill the solar loop or allow water into the storage tank. You can check the system for leaks using air or liquids.
Radiant floor installations rarely need more than seasonal adjustment. Typically, they are set up at the time of installation and just need to be switched on or off depending on the time of year.
At installation, the ball valve on the heat exchanger bypass stays about 1/3 closed at all times, forcing some of the hot solar fluid through the heat exchanger, but allowing most of it to go to the radiant floor heating (or shunt loop in the off-season).
Solar collectors are big, heavy pieces of equipment which are both very tough and very fragile at the same time. They weigh 85-140 pounds per collector (38-64 kilos) and are usually shipped on a pallet carried by a big rig truck.
So how are you going to get them safely onto the roof of your house? Carefully, that's how!
Solar thermal systems for pool heating are so common and mainstream that most manufacturers provide very detailed installation instructions. It is important to follow these instructions as they outline the most efficient way to install the equipment.
Although you may be (or think you are) an accomplished DIY expert, don't ignore the documentation – it often includes many useful hints and tips gathered from years of installation experience!
All types of solar thermal system need maintenance, though a well-planned installation using high-quality equipment needs very little compared to most active mechanical systems.
Pressurized systems for space heating are very similar to drainback installations, though they have additional considerations because the solar loop is always full. Unlike a drainback system, they can't just be switched off. This puts the system at risk of overheating during the hot months when it is not in use (assuming it is not drained).
Unlike liquid-based solar thermal systems, air-based installations do not suffer when they are allowed to remain idle. This advantage works to your benefit when setting up control systems, as you only need to figure out how to switch the system on when it's needed and off when it isn't.
