• SkillCat Team

Best Practices for Air Components Maintenance

Updated: Jul 12


Routine Maintenance: Residential Systems: Chapter 1


Air Distribution Components


By the end of this module, we will be able to:

understand inspection and operational checks,

demonstrate how to inspect and clean ductwork, and

demonstrate how to inspect and clean air filters Skip to quiz!


Intro to Routine Maintenance


Routine maintenance of a system is a regular check-up for a system. Routine maintenance involves:

  • looking for common problems,

  • solving them, and

  • cleaning the HVAC system.

We should check the system just like a doctor checks for any health issues and gives tablets to solve them.


We perform operational checks to ensure that the system works properly. The system should work as per the manufacturer’s instructions.


During maintenance, we need to ensure that:

  • the system is working correctly,

  • it is operating safely,

  • the fuel and electricity bills are efficient and optimal, and

  • the equipment has prolonged life

Recall the working of an HVAC system. We can see a concise video to the right. The goal of the HVAC system is to provide human comfort by maintaining temperature and humidity in the room.



Inspecting Ductwork


Recall that ductwork is a closed pathway made of thin metal sheets. Two main purposes of the ducts are:

  • To provide a path for the hot or cold air to reach the rooms from the HVAC systems.

  • To not allow the transfer of heat between the air inside and outside the ductwork.


.There are generally two types of ductwork that you will see on sites:

  • Rigid ductwork - Maintain an exact shape and cannot bend easily.

  • Flexible ductwork - Can bend as needed.


Three problems are common in ductworks that need to be inspected

  • Dents,

  • Leaks, and

  • Clogs

These problems can be seen in both types of ducts. We will talk in detail about these problems.


Recall that ducts are made of thin sheets of metal. Just how hitting a car can put a dent on it, a heavy blow on the ducts can quickly put a dent on it. We can find damages on the duct inspecting visually.


Recall that air contains many debris, dust, soil particles, etc. As air continuously flows inside the ductwork, the particles stick to the walls of the ducts. You can use a flashlight to check for dust and debris stuck inside the ducts.


As ductworks are made by joining thin metal sheets, there is a chance that it may open. A small opening in the ducts will cause the hot or cold flowing inside to leak out. This causes problems like insufficient cooling as the air cannot reach the exact rooms.


Leaks in the ductwork can be inspected visually from the outside. You can use a flashlight to carefully go around check the ductwork for leaks.


Recall that ducts are made of metal. Ductworks have a chance of corrosion. You can visually inspect the insides of a duct for signs of corrosion using a flashlight. Sign of corrosion usually means that you will have to replace that part of the duct.


As ducts are made generally closed, there are chances of mold and fungus growing inside the ducts. This would be a common problem if the HVAC system were shut down for a long time. We can clean the mold with a cloth or mop dipped in a regular bleach solution.


You may face a situation where you suspect that you can find problems

  • In an area that cannot be seen easily, using a flashlight

  • deep inside the ductwork.

In such cases, we use an inspection camera to look inside the ducts. An inspection camera has a camera attached to a long cable inserted inside the ducts for inspection.



Cleaning Ductwork


We always clean the ducts during regular maintenance. Duct cleaning involves cleaning

registers and the insides of the ducts using a vacuum cleaner. Recall that registers are the grills that we find in the walls at the duct entry.


First, we switch off the HVAC system. Then we unscrew the registers. We have to clean the walls with a brush as far as we can reach. We need to collect the loosened dust and dirt with a vacuum cleaner by inserting a hose into the duct. We need to wash all the registers with water.


We have to wash the air filters if they are reusable or replace them. We have to clean any dust that might have come out of the vent and onto the floor. Finally, we will screw the registers in the place as before.


Inspecting Air Filter


Recall that an air filter traps the dust particles and debris from the air. It is like a face mask for your home and the HVAC system. Advanced air filters also remove pollen, bacteria, and

allergens from the air.


Air filters have the capacity to collect dust particles. As more dust is trapped by the filters, it gets clogged.


Imagine putting on a dirty mask that makes you gasp for breath. Similarly, if the air filter is

clogged with dust, it does not allow air to flow easily via the ducts in the HVAC system. So, the HVAC system has to work harder to provide you the same cooling or heating effect.


Air filters can be visually checked if they are clean or dirty. You can see the air filter in an HVAC system by removing the side access panel. Pull out the air filters by removing the access panel and check it visually.


Cleaning Air Filter


Recall that some air filters are reusable and can be cleaned. We can clean an air filter with water. We can use a garden hose to clean the reusable air filters.


While washing, make sure that the water pressure in the hose is low. High-pressure water might tear and damage the filter.


Here are the steps we need to follow while cleaning an air filter:

  • Remove the filter and wash it with water.

  • Make sure the filter is dry before replacing it.

  • Insert the filter back.

We can only clean reusable filters. Other filters must be replaced.



Replacing Air Filter


Non-reusable air filters cannot be washed and need to be replaced. You can pull out the air filters by removing the access panel and insert a new one.


All air filters have an arrow marked on it. This arrow is the direction in which the air should

flow through the filter. So while inserting the filter back, we should see the direction in which the air flows in the ducts and point the arrow in the same direction.


Routine maintenance involves:

  • looking for common problems,

  • solving them, and

  • cleaning the HVAC system.

We inspect for dents, leaks, and clogs in ductwork. We clean registers and the insides of the ducts during ductwork cleaning.


If the air filter is dirty

  • we have to clean the washable filter and reuse it, or

  • we have to replace it with a new filter.

Air filters have arrows printed on them that show us which way they are supposed to be installed.



Question #1: What do we need to ensure during routine maintenance of HVAC system?

  1. the system is working properly and safely

  2. the fuel and electricity bills are efficient and optimal

  3. the equipment has prolonged life

  4. All the above

Scroll down for the answer...














Answer: All the above

During maintenance, we need to ensure that:

  • the system is working correctly,

  • it is operating safely,

  • the fuel and electricity bills are efficient and optimal, and the equipment has prolonged life.


Question #2: An HVAC system had been shut down for three months as the owners were on vacation. What should you likely check during routine maintenance?

  1. Air Filter

  2. Access Panel

  3. Traces of mold and fungi in the ducts

  4. Dust on the air filters.

Scroll down for the answer...









Answer: Traces of mold and fungi in the ducts

The access panel is the outer cover of the filter. It is the first component you should remove to gain access to the air filter.


Question #3: What do we clean during the ductwork cleaning?

  1. Air Filter

  2. Register

  3. Ducts

  4. All the above

Scroll down for the answer...










Answer: All the above

We clean the insides of the ducts, registers, and air filters during ductwork cleaning.


Question #4: While inspecting an air filter, which of these components will you remove first?

  1. Air Filter

  2. Access Panel

  3. Grilles

  4. Duct Joints

Scroll down for the answer...















Answer: Access Panel

The access panel is the outer cover of the filter. It is the first component you should remove to gain access to the air filter.


Question #5: We clean the reusable filter with water.

  1. True

  2. False

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Answer: True

The steps we need to follow while cleaning an air filter:

  • Remove the filter and wash it with water.

  • Make sure the filter is dry before replacing it.

  • Insert the filter back.

We can only clean reusable filters with water and reuse them. Other filters must be replaced.


Question #6: During routine maintenance for a system having a reusable air filter, you should ____ the filter and see that the ____.

  1. Wash; filter arrow is pointing the same as the direction of airflow.

  2. Wash; filter arrow is opposite to the direction of airflow.

  3. Change; filter arrow is opposite to the direction of airflow.

  4. Wash; filter arrow is pointing the same as the direction of airflow.

Scroll down for the answer...
















Answer: Wash; filter arrow is pointing the same as the direction of airflow.

During routine maintenance for a system having a reusable air filter, you should wash the filter and see that the filter arrow is pointing same as the direction of airflow. Recall that reusable filters can be washed with water. They need not be changed.

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