The winters and cold climate call for a constant source of hot water for comfortable baths and daily use, but using water heaters daily can lead to a sharp rise in your energy costs. That’s why more and more households are switching to various types of solar water heaters to meet their needs while still staying within their budget.
To make your life easier, we have prepared a comprehensive guide on the top 5 solar water heaters, so read this article until the end. This guide will help you choose the best solar water heater to fit your needs.
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5 Types of Solar Water Heaters
Utilizing the sun to heat water is a great for the environment and your bottom line!
Here are five different types of solar water heating systems you should consider:
1. Direct Circulation Systems
These hot water systems carry the cold water from a storage tank to a collector during the day hours, where they absorb the maximum heat from the sun. To minimize the chances of freezing, you can either recirculate hot water from the storage tank or flush the collectors down the drain.
Although these active systems can work in winters, they’re best used in areas that do not frequently reach freezing temperatures.
Recirculating heated water and transporting the water from storage tanks to the collector adds up to the responsibilities of your electric pump, taking your energy bills a notch higher.
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2. Indirect Water Heating System
Try an indirect heating system if you are looking for much more efficient water heaters. These water heaters circulate an anti-freeze liquid in a closed loop around the water collector to keep it from freezing. The heat from the anti-freeze liquid is then transferred to the water in the storage tank through a heat exchanger with 85% to 90% efficiency.
Usually, indirect systems use antifreeze liquids like water-propylene glycol and water-ethylene glycol solutions. Since the heat is neatly transferred from one source to another, it also minimizes energy wastage and helps the model stay sustainable.
3. Thermosiphon Systems
These water heaters use antifreeze or hot liquid to keep the water from freezing. The storage tanks are placed higher than the collectors, and the water is encouraged to rise naturally by convection. These systems work best in areas that receive adequate solar energy to make the water molecules expand and rise.
Since they do not need the help of electric or heat pumps to make the water rise, the efficiency of these systems is directly proportional to the amount of solar energy they receive. So, although it might be a little time-consuming, they are undoubtedly energy-efficient.
4. Drain Down Systems
These water heaters belong to the tribe of indirect water heating systems. The only difference here is that the water is circulated through a closed loop. During circulation, the heat energy is transferred to potable water using a heat exchanger with commendable efficiency.
Another benefit of these water heaters is they run even in the absence of sunlight. During those hours, the water is drained from the collector naturally using gravity which protects the water from freezing.
Despite its flexible service, it’s best to use drain-down systems in areas that receive sunlight throughout the year.
5. Air Systems
Air systems are a type of indirect water heating that uses hot air propelled by a fan instead of an anti-freeze liquid to protect the water from freezing. Here, the fan propels a gush of air to the water collectors, followed by a heat exchanger before ultimately reaching the storage tank.
The huge drawback is that, unlike traditional indirect water heating systems, the heat exchanger’s of air systems are only 50% efficient. Plus, the fan used to propel the air requires external energy to run, which increases your energy bills ever so slightly.
3 Types of Solar Collectors for Water Heaters
Your choices do not end at the water heater alone. It’s time to pick the collector that will perfectly complement your water heating system. Here are the three types of solar collectors you can choose from:
1. Evacuated Tube Collectors
These collectors are best known for being highly energy efficient with their superior insulation techniques. Here, the heat transfer fluid is held in glass tubes laid side by side. Each tube has a double-layered glass enclosure with a layer of vacuum between the outer and inner surface to minimize heat loss.
These collectors work best in the daytime when high temperature and direct sunlight.
2. Flat Plate Collectors
As the name suggests, these solar collectors consist of a flat panel box containing the heating fluid tubes. The box is then mounted on a dark-colored absorber. The biggest benefit of using these collectors is they can retain and convert solar heat even under humid conditions and diffused sunlight.
3. Parabolic Trough Collectors
These collector panels use a long u-shaped mirror to concentrate the sun rays on the heating fluids which are embedded along the length of the mirror. The constituting tubes are well insulated to minimize heat loss. For best results, use these collectors in areas that receive intense sunlight for long hours. Just make sure you have enough roof space for them.
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Frequently Asked Questions
How Long Can Water Stay Warm in these Types of Solar Water Heaters?
The ability to retain warm water depends on the insulation of the system. If the insulated tank, tubes and collectors are efficient in trapping heat, the water can stay warm for up to 24 hours.
Do They Work at Night?
A solar water heater can only work at night if it has batteries that store thermal energy during the day. If not, you can always use the water from the hot water tank at night.
Can Solar Water Heaters Work on Cloudy Days?
A few clouds cannot block out the energy from the sun. Having flat plate collectors that work well even under extreme humidity or diffused sunlight can be of great help.
As long as you choose the best type of solar water heater that matches your needs, switching to a solar-powered heater can be the best decision you can make.
A nice hot water storage tank from renewable energies like solar power that amps up your energy savings is certainly a hard-to-refuse offer, isn’t it?
Finding a residential solar hot water heater for your home