A Solar Power Heater For All Climates - The Drainback Closed Loop Solar Water Heater
A solar power heater for the home water supply is the economical and logical first step many homeowners take when they look to employ a solar power plan in their home. A solar water heater uses less technology than most solar devices, and is easy for the layman to understand. Water exposed to sunlight gets hot, this heat kills any germs that may have resided in the water, and it can now be used for bathing, cleaning, washing clothes and cooking.
Solar power heating also provides monthly savings that are both instant and noticeable. Most solar power heater systems pay for themselves in the first two or three years, and cost relatively little. And the ratio of dollars saved to dollars spent is actually higher than with solar electric power generation.
But every solar heater is not the same, and you must choose one that performs correctly for your climate. Not sure which solar water heater technology to choose? Take the safe route and purchase the one that was designed to work in most climates worldwide.
Dubbed Drainback Systems because of their failsafe ability to clear the lines and collector when temperatures are temperate or very hot, the indirect, closed loop solar power heater is not the best choice for extremely cold climates. They are more expensive than ICS water heaters, and harder to install, but are a safer play when temperatures start to climb into the 90s.
The solar power heater controller has two sensors that let the pump know when water temp gets too high. To avoid boiling water cracking the pipes, water is pumped back into the drainback tank. Obviously, your collector has to be placed higher than the drainback tank, so consider this before buying. Some closed loop systems employ antifreeze, but high temps in the summer can break it down, rendering it ineffective. Water is the best bet.
Instead of trying to calculate your solar power heating needs, purchase an all-in-one solar water heater kit and have it installed by a skilled contractor familiar with solar power heater systems. The average DIYer may be tempted to tackle this project, but a small error on install could mean faulty results, or full-blown re-installation later.
Some homeowners try to stay "all solar" in their thinking, and use a photovoltaic pump to move the water back up to the collector. This is not a good idea in case of periods of low sunlight. Install an electric pump more than capable of handling the solar water heater movement, and don't try to save a couple of bucks by minimizing your calculations. Again, a knowledgeable solar professional can answer all your questions here.
There is a catch 22 you need to understand when installing the drainback tank. You want it high enough to drain properly and fully, but you need it low enough to allow all of the parts exposed to the weather to drain back completely. Also keep the distance minimal from your collector to drainback tank in your solar power heater system. This will lower the amount of time your pump runs, which will keep your electrical costs at a minimum.
Purified water works best in the closed loop system, but is more prone to freezing. To combat this, allow for a minimum 15 degree slope. Calculating for eventual sagging of longer pipes will promise perfect drainage and flow even if your pipes do eventually bend a little over time. One error made by even the savviest of do-it-yourselfers is the use of 90 degree connectors when installing their solar water heater. Using two 45 degree bends and copper pipe of at least 3/8" will keep water from collecting and freezing.
When installing a solar power heater system for your home's water supply, going with a Drainback solar water heater is a safe bet for performance and damage-free reliability in all but the coldest of climates. And leaving the job up to a professional will save your back and provide peace of mind while your savings add up.