Importance of a Filter Drier

  September 1, 2017      Jeff Rosenblum


Hello all! For this Supply Chain our Technical Tip is straight from Allied Air regarding the use of a filter drier. Using the correct drier and following proper installation procedures will aid in the longevity of the system.

A filter drier is designed to remove moisture from a refrigeration system. It uses desiccant material or a substance to absorb the moisture in the system. The desiccant is designed for a specific oil base in the refrigerant system and should not be interchanged. It also filters foreign particles, which prevents these substances from circulating in the system. If moisture is not removed from the system it can cause hydrochloric and hydro fluoric acids to form, which can damage the system.

A liquid line filter drier needs to be used in any new installation and any time a system is opened to the atmosphere. On the Allied product line, most models have the liquid line drier already factory installed. If not, it is shipped with the outdoor unit. A liquid line filter drier is used because refrigerant in the liquid state is the best place to catch moisture in the system.

There are two different types of liquid line filter driers and do not need to be confused. The first is a one-way drier, which is primarily used on straight air conditioners. The second type is a bi-flow liquid line filter drier that is primarily used on heat pump type units. To prevent getting these two liquid line driers confused there is an arrow on the drier to show which direction the refrigerant may flow. These flow directions are extremely important. If not selected correctly this will create a restriction in the refrigerant circuit causing nuisance calls and extended time trouble-shooting the equipment. If you need technical assistance please call the Famous Supply Tech Support Team.

Jeff Rosenblum 
Technical Support
18 Years Industry Experience
Cell (330) 962-2491
[email protected]