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Have Your Changed Your HVAC Filter Recently? Here’s Why It’s Important


If you polled all professional HVAC companies and asked them what is the one piece of advice they would give homeowners about their heating and cooling systems, almost all would give the same answer:

Please regularly change the HVAC system’s air filter! Every one to three months.

It’s a simple job, taking only a few minutes, and it makes an enormous difference in how the AC and heater run. Perhaps because it’s so simple, people often forget about it and leave the filter in place. When the filter becomes clogged, it creates serious problems that can lead to needing heating or air conditioning repair in Portland, OR.

Why This Filter Is Important

Before we get into what might happen if you leave a clogged filter in the HVAC system, we need to explain what the filter is there for in the first place. It isn’t to clean the air. The filter’s job is to protect the interior components of the HVAC cabinet (which includes the blower, air conditioner evaporator coil, and the furnace) from getting dusty and sustaining damage. Dust and debris can lead to problems like frozen coils and burnt-out motors. 

It takes from one to three months for the filter to become clogged with the debris it has trapped. Filter strength affects this timespan: basic panel filters need monthly changes, while pleated filters last for longer.

How a Clogged Filter Can Make Trouble

When a filter clogs completely, it restricts the flow of air into the HVAC system. This leads to several problems. Here are the most common:

  • Tripped circuit breaker: The strain placed on the blower fan can cause its motor to overheat. This will trip the circuit breaker for the HVAC system and cause it to shut down. 
  • Higher energy bills: When the blower motor has to work much harder to draw air through the return air ducts, it will raise the cost to run it. You’ll pay more for poorer performance. 
  • Frozen evaporator coil: During periods when the AC is running, the blower moves warm air across the cold evaporator coil to cool it down. A clogged filter chokes off how much warm air the blower can move, leaving the coil too cold. A cold coil will develop ice, and that can soon mean the end of any cooling.
  • Short-cycling: This is when the AC or heater shut off early before completing a full cycle, which wastes energy and places too much stress on the HVAC system. A clogged filter is one of the common causes of short cycling.
  • Damage to internal components: A clogged filter will eventually fail at doing its job of protecting the HVAC system. When the filter is fully congested, it will start to bend from the air pressure placed on it, and this allows dirt and debris to slip in around the edges.
  • Ruined blower: In extreme cases of a clogged filter, the filter may collapse entirely and fall into the blower, often catastrophically damaging it. 

This all sounds bad, but the good news is it’s easy to avoid. Check your filter monthly to determine how fast it collects dust and debris. You’ll develop a schedule for regular filter changes this way and keep your HVAC system working right. 

Clawson Heating & Air Conditioning is “Connecting People to Comfort”! Call us whenever you need air conditioning or heating repair.

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