• SkillCat Team

Residential Maintenence: Inspect & Clean Air Handler

Updated: Jul 12


Routine Maintenance: Residential Systems: Chapter 3


Indoor Unit Components


In this module, we will look at how to inspect and replace an air handler. We will also look at how to inspect and clean an evaporator.Skip to quiz!


Inspecting Air Handler


Recall that an indoor unit of the centralized HVAC system is the air handler. As the name suggests, an air handler handles the air inside our home. It is used to cool or heat and circulate a large amount of air throughout the room via ductwork. Recall that ductwork is a closed path for circulating air.


An air handler is usually a large rectangular metal box that is connected to the ductwork. The air handler contains an air filter, blower, and heating and cooling components. A furnace or air conditioner without an air handler will not circulate hot or cool air properly to our home.


While inspecting the air handler, we check for any noise or vibration during its operation. We need to switch off the unit to open the access panel to check any dust or dirt inside the air handler. We also inspect its wiring for damage or loose connections.


Recall that an air filter is a part of an air handler. Air handler inspection includes inspecting the air filter. We check the air filter if it is clean or dirty. We have already seen how to inspect and replace an air filter.


We also inspect the evaporator coil while inspecting the air handler. Recall that the evaporator coil cool the air that passes through it. We check the evaporator coil if any part of the coil surface is damaged.


We check the drain line whether the water is flowing freely or not. Recall that when the air passes through a cooling coil, moisture in the air converts into water. This condensate water is moved out of the HVAC system using a drain line.


We check for any dust on the blower. We check for the free rotation of the blower. We also check for the tightness of the blower motor belt.


Cleaning Air Handler


For cleaning the air handler, we first need to switch off the air conditioner to open the access

panel. We can then clean the dust inside the air handler. We also need to clean or replace the air filters.


We also need to clean additional air handler components such as:

  • evaporator coil,

  • drain pan and drain line, and

  • blower casing and wheel.

We will see how to clean these components.


Cleaning Blower


The blower is one of the main components of the air handler. Recall that blower is a type of fan that forces air to move through the ductwork into the home. We have to clean the blower while cleaning the air handler.


For cleaning the blower, first we need to switch off the air handler to open the access panel. After we locate the blower, we unscrew it and separate it from the air handler. We need to clean the blower properly and place it back, as shown in the video.



Replacing Pillow Block Bearings


Pillow block bearing is used in some HVAC systems to support the blower shaft. A bearing is supports the loads and also helps to rotate. A pillow block bearing is a type of bearing. It is housed within a cast-iron mounting bracket. Let us see how to replace it.


For replacing the pillow block bearing, we need to switch off the power of the air handler to remove the belt from the pulley. We loosen the screw of the pulley and remove it from the shaft. Then unscrew the mounting screws of the pillow block bearing and remove it from the shaft using a bearing puller.


We have to place the new pillow block bearing in the shaft and adjust its position. We tighten the mounting screws and place the pulley onto the shaft and tighten the pulley screw. Finally, we place the belt onto the pulleys and check proper operation by switching on the air handler.


Cleaning Evaporator


Evaporator coils are found in indoor units of air conditioning systems. We can see evaporator fins on the evaporator coil. Recall that evaporator fins are thin metal plates that run along with the coil. As air passes through the evaporator, it gets cooled.


If we find any dust on the evaporator during the inspection, we need to clean it. Let us see how to clean the evaporator coil.


First, we need to clean the evaporator coil with a brush. We should not bend the evaporator fins while cleaning with the brush. We have to clean the evaporator coil with coil cleaner till it gets cleaned fully.


We have to straighten the evaporator coil fins with a fin comb if they are bent. This process is similar to combing our hair. We should straighten the fins slowly. Else it may damage the coil.


The air handler contains an air filter, blower, and heating and cooling components. We inspect all the components of the air handler and clean them during its maintenance. For cleaning the blower, we need to switch off the air handler to open the access panel.


First, we clean the evaporator coil with a brush. Then we clean the evaporator coil with coil cleaner till it gets cleaned fully.




Question #1: Inspecting air handler involves inspecting

  1. Air Filter

  2. Drain line

  3. Blower

  4. All the above

Scroll down for the answer...










Answer: All the above

The air handler contains an air filter, blower, and heating and cooling components. We have to inspect all the components of the air handler during its inspection.


Question #2: We clean the blower casing and blower wheel during air handler cleaning.

  1. True

  2. False

Scroll down for the answer...










Answer: True

The blower is a part of the air handler. So we have to clean it during air handler cleaning.


Question #3: We clean the blower without removing it from the air handler.

  1. True

  2. False

Scroll down for the answer...













Answer: False

For proper cleaning of the blower, we have to separate it from the air handler and clean it.


Question #4: Pillow block bearing is used to support _______ in the HVAC systems.

  1. Burners

  2. Evaporator coil

  3. Blower shaft

  4. Drain line

Scroll down for the answer...














Answer: Blower shaft

A pillow block bearing is a type that is housed within a cast-iron mounting bracket. It is used in some HVAC systems to support the blower shaft.


Question #5: Which tool is used to straighten the bent fins of the evaporator?

  1. Screwdriver

  2. Fin comb

  3. Cutting plier

  4. None of the above

Scroll down for the answer...















Answer: Fin comb

A fin comb is a tool used to straighten the bent fins of the evaporator coil.

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