A couple of months ago, the HVAC unit in my home started malfunctioning. The temperature inside my home soared to over eighty degrees Fahrenheit, even though my air conditioning system ran nonstop. After inspecting my air conditioning unit, my knowledgeable HVAC contractor recommended I purchase a new system. He discussed the pros and cons of installing different sizes of HVAC units with me. After considering my HVAC contractor’s advice, I decided to purchase a three and a half ton HVAC unit. Shortly after my HVAC contractor installed my new air conditioning unit, my house started feeling more comfortable. On this blog, I hope you will discover how an HVAC contractor can help you select the right air conditioning unit for your home. Enjoy!
A central air conditioner that freezes up frequently is not a problem that you should have to live with. Whether the problem is worse in hot weather or your unit is freezing after every use, there are a few steps you can take to get to the source of the problem. Here are some tips that can help your air conditioner run more smoothly.
Check the Evaporator Coils
When you notice that your air conditioner is not putting out cold air like it should be, the first thing you should do is turn it off at the thermostat. The longer your air conditioner continues to run after it has frozen up, the more ice will accumulate, and the longer the unit will take to thaw. You can inspect the evaporator coils after turning off the air conditioner by removing the furnace access panel. Depending on the type of furnace you have, the panel may simply slide off, or it may be held in place with screws.
The evaporator coils can be found above the furnace blower in an A-frame configuration. If your air conditioner has frozen up, you will see a thick accumulation of ice on the coils. Do not try to scrape the ice off the coils, as this can damage them. Instead, you can run your air conditioner in fan-only mode until the coils defrost as a temporary solution. For a permanent fix, you should try to solve the two most common causes of freezing: airflow restrictions and refrigerant leaks.
Restore Airflow
Under normal circumstances, the refrigerant inside your evaporator coils cool the air that is blown into your home while the warm air that flows into the coils keeps condensation on the coils from freezing. If airflow to the coils is reduced, the condensation will freeze on the coils before it can drip into the drain pan below the coils.
Airflow to your central air conditioner can be blocked at a number of places within the system. The most common culprit is a dirty furnace filter. The warm air that is blown across the evaporator coils is first drawn through the furnace filter to remove dust, pollen, and other airborne contaminants. If the furnace filter is clogged, your evaporator coils will not receive enough air to prevent freezing. You can avoid this problem by cleaning or replacing your furnace filter at least once a month.
If your furnace filter is clean and your air conditioner is still freezing up, the next most likely cause of restricted airflow is a blockage in the return duct. The return ducts draw warm air inside your home back into the system to be recirculated. Dust and debris can accumulate on the return vents over time and prevent this warm air from getting to the evaporator coils. You can sometimes solve this problem by wiping down the return vents in your home and using a vacuum-hose attachment to clean the insides of the return ducts. In extreme cases, a professional duct cleaning may be necessary to remove all the blockages in your home's ductwork.
Get Professional Refrigerant Leak Repair
If airflow is not the problem, your air conditioner may be freezing up because it is low on refrigerant. The refrigerant in your evaporator coils cools the air by expanding inside of the coils. This expansion creates a drop in temperature due to a physics principle known as the Joule-Thomson effect. When your air conditioner is low on refrigerant, the remaining refrigerant in the coils will have more room to expand. This creates a greater drop in temperature than the coils were designed for and causes them to freeze up.
Your air conditioner does not consume refrigerant. The refrigerant circulates in a closed loop between the outdoor condenser and the evaporator coils above your furnace. This means that the only reason your air conditioner would be low on refrigerant is if it has a leak. Leaks often occur inside the condenser unit, making them difficult for homeowners to detect, and they must be repaired by a professional. Contact an HVAC technician who provides cooling services if your air conditioner is still freezing after you have cleaned your furnace filter and attempted to remove airflow blockages in your return ducts.
Keep these tips in mind so you can solve central air-conditioner freezing issues and keep your home cool and comfortable in the summer.
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