Deaeration

• annoying sounds in radiators, heat exchangers, pipes and pumps,
• difficult and prolonged installation adjustments,
• needing to deaerate by hand,
• decreased pump performance,
• insufficient heat emission or cooling efficiency,
• rapid wear and tear of installation components such as heat exchangers, controllers, shut-off valves and pumps,
• contamination of pipes and installation components,
• malfunctions, or even complete installation failure.

All of these issues result in extra energy consumption and complaints from residents, and they often require immediate follow-up.

So should this air be removed?

Yes indeed, but that will not happen by itself. Air is often dissolved in the installation fluid or is present in the form of tiny bubbles (micro-bubbles). Regular rapid deaerators cannot remove this air adequately. The air is taken along in the circulation and will cause the issues mentioned above.

Air can be present in an installation for various reasons. The most common are:

• filling and refilling the installation 
• modifications and maintenance 
• micro-leaks and diffusion via couplings, gaskets and plastic pipes 
• open expansion systems and cooling towers 
• incorrect expansion volume or incorrect pre-pressure 
• laws of physics, especially Henry's Law*.

* Henry’s Law: “Gas will dissolve in a fluid until there is an equilibrium between the partial pressure of the gas and the pressure in the fluid.” This means that smaller amounts of dissolved gases can be present in a fluid as the temperature rises or the pressure drops. In other words, a fluid will absorb more or less gas or release dissolved gases in certain locations in an installation under the influence of pressure and temperature.

Proper deaeration means separating micro-bubbles

After initial deaeration, a fluid system such as a central-heating or cooling installation will contain a large amount of gases in the form of micro-bubbles. The development of the SpiroVent, which also makes it possible to remove the micro-bubbles from the water, means a big step in installation water conditioning.

The micro-bubble deaerator is based on the absorption process (Henry’s Law). When the fluid is heated or the pressure is reduced as in a central-heating boiler or the walls of a heat exchanger, air is released in the form of micro-bubbles (just look at the bottom and sides of a pan in which water is heated up to see how these micro-bubbles form…).