• Reasons for Little to No Airflow in HVAC Systems

    The aim of your air conditioner is to circulate air throughout your home to keep you and your family cool, while also filtering out any potential allergens, toxins or bacteria. It should help to keep your living conditions comfortable, while at the same time giving you clean and healthy air to breathe.

    So if your air conditioning system doesn’t seem to be blowing any air through your vents or if the air flow has decreased you have a problem. Let’s find out what might be going on and what you need to do to solve the problem…

    The Problem

    If your AC has stopped blowing air completely, or the air has become very gentle, then that means you have ‘low airflow’. This refers to the amount of air flowing over the evaporator coil and through the ducts. There are several potential reasons for this which in most cases can be prevented with regular air conditioner maintenance

    • Dirty Air Filter

    One potential issue is a dirty air filter. Over time, if the filter is not changed it will become clogged up with thick dust and dirt creating an air restriction in the system. This will cause the unit to starve for return air and in turn will decrease the amount of airflow and even cause the system to freeze in many cases. Air will become tougher and tougher to move and this will eventually bring it to a complete halt. This is bad news because the temperature will be on the rise in your home quickly. The trick is to regularly change or clean permanent filters every 30 days. We tell our customers during AC repairs to change their filter every time they pay an electric bill as a good rule of thumb. At the end of the day it always pays to replace your filter regularly!

    • Blocked Return Vents

    Return vents are where the air is returned from the conditioned space and recycled back to the air conditioning system. In some cases the return register/filter is located on the floor or down low on the wall. Many people are tempted to put a bookcase or desk over it to hide it which is fine as long as there is plenty of clearance for the the air to be pulled into the return air duct. If it is covered tightly the system will begin to starve for air and in turn cause low airflow or a freeze up.

    • Dirty Evaporator Coil

    If you have ran your air conditioning system without a filter installed for any length of time other than just to change it, all the dirt that you would normally see on the filter is now on your evaporator coil inside of your air handler or furnace. When this happens you will have the same outcome as a dirty filter (stated above) but with a much higher air conditioning repair bill. The only way to clean the coil is to cut a hole in the ducting (if accessible) and clean with chemical and a brush. In some situations the evaporator coil will actually have to be removed from the system to clean and reinstalled (this is a major repair and can be costly).

    • Damaged Duct System

    Air ducts can be damaged by rodents or more simply because of age, in this case you would be supplying air conditioning to your attic or crawlspace instead of your home! This can cause the entire property or even 1 or more rooms to not cool properly depending n the size of the air leak and location within the duct system. It’s a bit like having a hole in a straw and trying to drink a soda. You need to find that hole and patch it up as this can also cause moisture issues which is inviting to mold, termites and other insects.

    • Evaporator Blower Motor

    Your AC system has a blower motor located inside the indoor unit which is used to cool the air moving across the coil (coming from the return air duct), then flows into ducting, and into the property. This motor can fail just like anything else electrical does. Most common reasons for the motor not running are:

    1. The thermostat is defective and not calling for it to run.
    2. The relay that powers the motor is stuck open and is not supplying power.
    3. The capacitor that starts the motor is defective.
    4. The motor itself needs to be replaced due to damaged start winding or bearings.

    In any of the above cases an air conditioning repair company will be able to get the system up and running again if you are unable to DIY.

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