Choosing Between Solar Evacuated Tubes & Flat Plate Collector

Posted by Latitude51 Solar on December 15th, 2018

Choosing between solar vacuum tube and thermal plate collectors depend on the task you’re working on – the roof, the climate, the budget and the system type you’re using. This helps you make the right decision about solar collectors for your solar water heating systems.

There are several design parameters to consider while looking into a flat plate and evacuated tubes collectors. Here are some of them discussed below:

Cost

Flat plate collectors tend to be cheaper than evacuated tubes because of their simpler design and easier to manufacture. Flat plates are affordable collector to collector and also on BTU per dollar level. Evacuated tubes are considered to be 10-15% more costly than flat plates, but their processing costs are falling.

Warranty

Obviously, you want to design these systems to last 40 years, but they should be capable of. Flat plate collectors will tend to have longer warranties up to 20 years as compared to a 10-year warranty for evacuated tubes. This is presumably because of the level of sophistication with technology. You can check with the manufacturer and distributor of the collector to know their warranty period.

Installation

Flat plate collectors are heavier, take up enough space and can be cumbersome to install on specific roofs. Evacuated tubes comprise of lighter components and are easier to manage on the roof.

Reliability

Evacuated tubes are used more frequently in colder climates as they are more efficient than flat plates in extremely cold temperatures. They are considered to be a reliable alternative for solar water heating systems.

The use of water

You should know for what purpose you’re going to use the water and how much you’re going to utilize. Evacuated tubes can heat large amounts of water very fast and can get the water above 180 degrees. Do you have a sizable load like in commercial or space heating situations? You may want to look into solar evacuated tubes.

Structural wind loading –

If you’re in an area with significant wind loading, evacuated tubes have a great advantage. Generally, they are light because less water runs through the system and have less wind resistance. This means the wind can simply pass through the collectors.

Performance –

If you keep both types of collectors in side by side fashion on the same roof, the performance is solely depended on the difference between the entering water temperature that you’re heating and the ambient temperature.

In simple words, the performance depends on the temperature of the water coming from the storage tank as compared to the ambient temperature – the temperature of the surroundings. As the difference increases – when you’re in colder temperature, evacuated tubes become more efficient for use.

Conclusion –

The best one between a flat plate and solar vacuum tubes is it depends as they both work very well. If they are designed perfectly, you’re not going to see a huge difference between one and the other in most situations. It’s not like evacuated tube produces 100% hotter water at 50% less cost – it’s all about incremental performance considerations.

Author Information –

This article is written by Latitude51 Solar – offers best-in-class solar evacuated tubes collectors with state-of-the-art features to deliver maximum performance, durability and efficiency. More Information About Solar evacuated tubes Please click here