Filter Heaters: Protect Your System from Cold Air

Posted on September 29th, 2020

Systems tend to have a “sweet spot” when it comes to temperature control. Essentially, there is an ideal temperature range that allows the system to function properly. When the temperature rises or lowers outside of that range, problems to the system or end product can occur.

Frequently, when there is a temperature problem, it is due to overheating; however, that is not always the case. There are systems in colder climates or specialized industries that need to heat the air for the system to work correctly. In those cases, a compressed air filter heater is often necessary.

What is a Compressed Air Filter Heater?

Filter heaters can be added into a system to heat the compressed air to a controlled temperature generally between 68°F (20°C) and 248°F (120°C), although there is not an industry standard. Inside the heater, there is an open wound heating coil that works together with a temperature sensor to heat the air. When paired with a compressed air prefilter, the clean air will enter the system at the correct temperature.

Why Does a System Need a Filter Heater?

Maintaining the correct, elevated air temperature can allow any aerosols or liquid water in the lines to transfer into a vapor form, where it can often pass harmlessly downstream. Refrigerated air dryers can only lower the dew point of the air to around 39°F (4°C). If the ambient conditions drop below this point, water can once again condense in the airstream. Therefore, if you have piping that goes outside of the building, there is potential for system damage due to the water vapor in the air during colder months.

When air is compressed, it increases in pressure and gains heat, which is why compressors could overheat without a cooler. However, as air travels through the pipework of the compressed air system, it loses temperature. By the end of the line, the temperature could be very cold or even freezing, resulting in the potential for condensation. Additionally, if the air pressure is expanded to the atmosphere, as often happens with air tools, significant cooling may occur. This supercooled air can make handling the tools uncomfortable and may also allow condensate to drip from the instruments.

Risks of Having Condensate in Your System During the Winter

During the winter, even a small amount of condensation can cause a wide range of problems for a compressed air system. For instance, the water could freeze and result in pneumatic control valves freezing shut. Also, if the wet air manages to travel throughout the whole system, it could result in product damage or make breathing air applications dangerous for the consumer.

Choose the Best Compressed Air Filter Heater

The Walker Filtration filter heater range offers eight in-line heater packages that ensure a controlled compressed air temperature for industrial and breathing air applications. Our heaters adjust quickly to variations in the air pressure without deviating from the set temperature.

For more information on our compressed air filter heaters, click HERE for the datasheet or contact our sales team at

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