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Evacuated Tube vs. Flat Plate Solar Hot Water

We can all agree that harnessing free energy from the sun through the use of a solar hot water system is a great way to both reduce your water heating costs and your carbon footprint. However, it can be difficult to know which of the two main types of solar hot water systems is right for you: an evacuated tube system or a flat plate system.

For personalised advice on which type of hot water systems suit your needs, call your local hot water specialists at Sun City Hot Water & Plumbing on 1300 728 122.

Flat Plate Solar Hot Water Systems

What Is A Flat Plate Solar Hot Water System?

Flat plate solar hot water systems are the most commonly known systems as the have been around since the 1900’s. A flat plate solar hot water system uses solar collectors of made up of copper water pipes covered by a layer of thick black glass. The collector is connected to an insulated storage tank that is used to store the water once it has been heated.

How Does A Flat Plate Solar Hot Water System Work?

In a flat plate solar hot water system, cold water is fed through one end of the copper pipes to be heated. The glass above the pipes traps heat from the sun which heats up the pipes and the water running through them. Once the water reaches the other end of the copper pipe it is circulated back into the insulated storage tank to be stored until needed.

Advantages Of A Flat Plate Hot Water System

Price - The main advantage of choosing a flat panel solar hot water system is the price, as this system is cheaper to purchase and install when compared with an evacuated tube system.

Appearance - Another advantage of a flat plate hot water system is that they tend to be more aesthetically appealing to have on your roof. This is the roof component of a flat plate system is simply a black glass panel. Conversely, evacuated tube systems will sometimes have the storage tank attached to the solar collector making the system much more visible.

Evacuated Tube Solar Hot Water Systems

What Is An Evacuated Tube Hot Water System?

Evacuated tube hot water systems utilise the latest technology to maximise the efficiency of the system. An evacuated tube solar hot water system is made up of heat pipes surrounded by two glass tubes, an inner tube and an outer tube. The space between the two glass tubes is evacuated to create a vacuum. This helps to retain heat collected from the sun and reduce heat loss. The top of each evacuated tube is connected to a heat transferring device called the manifold. Within the manifold there is a water pipe that is connected to the insulated water storage tank.

How Does An Evacuated Tube Solar Hot Water System Work?

When the liquid inside the heat pipe is heated up using energy collected from the sun, it evaporates into a hot vapour that rises to the top of the pipe. The heat from the vapour is then transferred to the manifold at the top of the pipe. As the vapour cools it reverts back to a liquid and returns to the bottom of the pipe to be reheated. Cold water is pumped through a pipe in the manifold where the heat is transferred to the water. Once heated the water is returned to the storage tank.

Advantages Of An Evacuated Tube Hot Water System

Efficiency - One of the greatest advantages of an evacuated tube hot water system when compared with a flat panel system is the efficiency with which heat is transferred. In fact, evacuated tube systems are up to 163% more efficient at transferring heat than flat plate systems in Australian conditions.

The added efficiency of an evacuated tube system enables it to heat water to temperatures of over 90 degrees celsius in whereas, flat plate systems will only heat water to 60 degrees celsius.

Additionally, due to the rounded shape of the evacuated tube system, water can be heated from early morning to late afternoon. Conversely, flat panel systems work best only when the sun is perpendicular to the solar collector.

Cheaper Repairs - Another advantage of an evacuated tube system is the repairs. In an evacuated tube system, each tube can be individually removed and replaced when damaged, reducing the cost of repairs. Conversely, flat panel systems tend to be more expensive to repair when damaged as they lack the modular design of the evacuated tube system.

Works In Most Weather Conditions - Evacuated tube hot water systems also outperform flat panel systems when it comes to heating water in colder weather. Although each system uses the heat in the air to heat the water, evacuated hot water systems still work in much colder temperatures than their flat panel counterparts providing hot water all year round.

Which Is Best - Evacuated Tube Or Flat Panel Solar Hot Water Systems?

Still not sure which solar hot water system is right for you? Get in touch. Sun City are your local hot water experts for the Sunshine Coast & Brisbane North. Call us today on 1300 728 122 to speak with a hot water expert. We offer reliable hot water system installations, repairs, and maintenance at competitive prices!

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