HVAC maintenance should be a top priority for anyone who owns central heating and air systems, but you might be surprised by the number of people who don’t know how to care for their climate control equipment properly. Then again, maybe you’re one of them! Not to worry — if the terms you hear certified technicians use are confusing you, you’ll probably need to do a little more research so that you can gain a better understanding of their work. Still, you’re in the right place: we’re here to give you valuable information you can use to take better care of your HVAC and enjoy more consistent, cost-effective service. Ever wondered how to charge an AC unit? This post’s for you.
Charging an AC unit is an integral part of making sure it functions in an energy-efficient way. Hold on a second; you might be thinking. What on earth is a charge? Does it have something to do with your circuit breaker or the batteries in your thermostat? The answer is no. Charging an AC is a procedure that concerns the refrigerant it uses to facilitate temperature changes when the system is running. Refrigerant is made from Freon — a substance with relatively high volatility that can easily be manipulated by the mechanical systems in your air conditioner.
Before You Learn How to Charge an AC Unit, Learn Why it’s Necessary
Why does the process of manipulating freon matter? Simple: as freon passes through your system, it undergoes numerous changes in state. As it does, it either absorbs or releases heat from the air around it. The following is a breakdown of the refrigeration cycle in brief:
- Refrigerant starts out as hot, low-pressure form of freon gas. When it moves through the condenser in your air conditioner, it is compressed — which adds pressure to it.
- The refrigerant then moves into the condenser, where it is condensed into a liquid form. As this occurs, it releases the heat it contains to the air outside your home.
- Next, the refrigerant travels through the expansion valve, which restricts the flow of the liquid and forces its pressure to drop.
- When the refrigerant (now a low-pressure liquid) enters the evaporator, it absorbs heat from the air inside your home and turns it into a gas. As it absorbs heat, it lowers the indoor temperature to the level indicated by your thermostat.
- The refrigerant has now returned to being a low-pressure gas. It enters the compressor once again, and the cycle repeats itself.
- Freon’s sensitivity to heat and pressure makes it an ideal chemical for use in refrigerant, but that also means it must be present at precise levels within your system. If the refrigerant level — or charge — is out of balance, each of the components mentioned above will overwork themselves trying to achieve the necessary results. For example, if not enough refrigerant is flowing into the compressor, it will have to work harder than usual to compress the amount that is present. As such, your system will draw more power, and the compressor will be more likely to wear itself out prematurely.
Is it Really a Big Deal? Actually, Yes
Many people don’t believe that a slight imbalance in their refrigerant levels will be enough to cause major difficulties in their AC system, or that these difficulties are likely to cost them substantial amounts of money. However, the cost of replacing a broken home air compressor can easily reach $1800. Remember: the compressor is just one of at least four essential components that handle the refrigerant in your HVAC. Replacing the evaporator coil can be a thousand-dollar fix too — so the last thing you want is to endanger these pieces by an incorrect amount of refrigerant in the system. It’s best to have a licensed professional charge the system whenever you suspect a leak so that you can avoid these costs.
How to Charge an AC Unit by Yourself
If you want to know how to charge an AC unit by yourself, the easiest way is to follow the manufacturer’s instructions. You’ll need to know the following:
- The suction pressure
- The outdoor air temperature
Once you do, simply add refrigerant until the pressure meets the level specified by your manufacturer’s chart. Once the charge is complete, check for a proper temperature split so that you can be sure the system will operate with a suitable level of airflow.
If you do not have a chart from your manufacturer explaining the correct charge levels for your equipment, do not attempt to charge the system yourself. Charging a system properly without this information requires specific conditions and the use of particular tools. It should only ever be undertaken by a qualified professional, so call your local HVAC company instead.
People who want to know how to charge an AC unit should be commended for taking the time to become better acquainted with their systems, but not everyone is equipped to perform this complex task. Only attempt to charge the system without professional help if you have significant experience and the correct information at your disposal.