Overheat in the UAE

In warm climates like the UAE, where solar thermal hot water systems can be prone to overheating, it’s essential to incorporate strategies to control the temperature. When the system has been designed with flat plate collectors or Evacuated tube collectors. Protection from overheating these highly efficient system will be required.

In the solar thermal industry, we call this stagnation. Stagnation occurs when a material cannot absorb heat and starts to radiate the heat. This can happen at different temperatures depending on the material. Copper and aluminium stagnate between 150 to 300 degrees Celsius if there is no heating being extracted from the collector. Pex and polymer absorbers stagnate between 70 and 87 degrees Celsius. High temperature stagnation can cause the collector to be damaged or reduce its life.

Flat Plate and Evacuated tube systems

Here is a list of methods that will all require technical and expensive control system to safeguard the overall system.

1. Heat Dissipation or Dumping- Additional components required such as radiators.

2. Shading the Collectors- Mechanical shading requiring moving parts that are automatically controlled.

3. Night Cooling- A controller with dual functions and automatic settings.

4. Controlled Collector Tilt- Mechanical control requiring moving parts that are automatically controlled

There are non-mechanical control methods that can involve modifications to the system to change their efficiency to suit the climate they are install in.

1. Oversizing the Storage Tank- Larger volume of store water will take longer to fully heat. Allowing the collectors to keep cooler for longer periods.

2. Under sizing the Solar Thermal Collectors- Will take longer to heat a storage tank. Allowing the collectors to stay cooler for longer periods.

Both solutions will change how the end user uses the hot water system due to longer reheat times in the colder months. Oversizing the storage tank will increase system cost while under sizing will reduce installation cost but could require back up heating to fully satisfy the users requirements.

Solariskit solar collector is perfect for the warmer climate

The prism collector has been designed to work in extreme heat climates like the UAE.

-          No need to undersize the collectors.

-          No oversizing the storage tank required.

-          No requirement for Mechanical shading.

-          No need for mechanical tilting.

A scalable solution for warm climate to satisfy the needs of the end user without expensive control system, whatever the weather.