Your air conditioner keeps your home safe and comfortable during the hot Tucson summers. While it might seem like a complicated system, it is actually quite simple, but it does need some attention throughout the season. How does it work, and what do you need to do to keep it running?

Air Circulation
The first thing you already know about your system is that it must circulate air to run. It does this by creating a high pressure at the outbound vents and a low pressure at the return vents. The system cools the air as it flows through and then forces it back out into your home.

A hiccup anywhere in the airflow prevents your AC from cooling your home. These problems may occur both in your home or in the system itself, but most are preventable.

Be sure you keep the vents clear so that air can flow freely from them. Remember, the air must be able to come up from floor vents and then circulate around the room.

If you put furniture over the vents, you inhibit proper air circulation. This inevitably leads to a room being uncomfortable while you’re paying to simply cool the furniture. Try to leave several inches above any vents open and then enough room for air to circulate around the vent.

Air circulation is also frequently restricted from within the system as well. We’ll discuss how to prevent these restrictions in the maintenance section below.

Circulating Refrigerant
Not only must your air conditioner circulate air, but it must also circulate refrigerant. This is what makes the air cold before it moves out through the ducts.

The refrigerant works by absorbing the heat from the air circulating through the system. It then transfers that heat to the air outside, which is why you have an outdoor unit for your central air system.

In order to do the job properly, your air conditioner must be able to regulate the pressure of the refrigerant. The expansion valve restricts refrigerant flow just before the evaporator coil, creating a drop in pressure and temperature. The greater the difference in temperature between the refrigerant and the circulating air, the more heat transfer takes place.

Once the refrigerant arrives at the outdoor condensing unit, the compressor increases the pressure and drives up the temperature. The hotter the temperature of the refrigerant compared to the outside air, the more efficient the heat transfer.

Getting the Right Size
BTUs, or British thermal units, are the size measurement for air conditioners. One BTU is the amount of heat needed to raise 1 pound of water by 1 degree Fahrenheit. You may also see some air conditioners sized in terms of tons of cooling capacity, with o1 ton equalling 12,000 BTUs.

In theory, it might seem that more cooling capacity would help cool your home more effectively. However, it is actually quite the opposite, with too much cooling capacity driving up costs and operational strain.

First, understand the more cooling capacity your air conditioner has, the more watts it takes to run it. Regardless of the temperature you have the thermostat set to, there is a minimal amount of power needed to run the unit.

Additionally, larger units cool the air faster, which also means they shut off faster. This reduces the amount of dehumidifying the system can do and also reduces the actual amount of air circulated.

Because your system is running shorter cycles, it will run them more often. When your unit first starts up, it uses about double the amount of power as when it’s already running. The starting process is also the most strain your unit experiences, so more frequent starts lead to more repairs.

The Importance of Ductwork
The ductwork is an often-ignored part of your air conditioning unit, but it’s extremely important to its effectiveness. The ducts transport the cooled air throughout your home and bring the warm air into your HVAC system.

There are two common problems people generally encounter with their ducts. First, they do tend to get dirty, which causes airflow restrictions that can cause inconsistent cooling throughout your house.

Second, the ducts may develop leaks over time, both from loose duct fasteners or too much pressure. Closed and blocked vents are a couple of causes of this increased pressure.

When your ducts have a leak in them, the cooled air seeps out on its way to your destination room. The result is less cooling in the intended room, with longer cycle lengths and more wear on your system.

Maintaining Your System
To keep your air conditioner working well, it needs regular professional maintenance. Most manufacturers consider this so important it is a term of keeping the warranty valid. To keep from voiding your warranty, a professional technician must perform this maintenance—not just a homeowner doing some of it.

As your air conditioner runs, it deposits small particles throughout your system. These particles eventually collect enough to restrict airflow, reducing your system’s efficiency.

Also, your system vibrates as it runs, which causes some of the system’s components to loosen. This uncontrolled vibration adds to the stress on those components, leading to more repairs and shorter service life.

A technician works to solve all of this during a routine service visit, which ideally happens in the spring. The goal is to make your system operate to the specified efficiency and experience the least amount of strain while doing so.

The first thing the tech does is clean the circulating fan and evaporator and condensing coils. This alone solves most of the airflow restrictions that occur within the system itself.

The tech will also check the refrigerant level to ensure there is enough to allow the system to run properly. Low refrigerant causes the system to freeze, leading to not only less cooling but also damage to your compressor lines.

Then, the tech will check all the mounting bolts for the fans, including the bolts for the condensing fan blades. They will also test the fan motors and lubricate the bearings if they aren’t sealed.

Lastly, the tech will also test the contractor and capacitor in the condensing unit to ensure both are working correctly. A faulty contractor may cause rapid cycling of your compressor, which will eventually damage it. The compressor will fail to start if the capacitor is faulty, and you may also hear a loud humming or buzzing sound.

In addition to routine maintenance, be sure to change your filters regularly. Most systems will need new filters about every 90 days, depending on your home’s air quality and filter type.

What Could Go Wrong?
There are several problems you may notice with your air conditioner over time. The fan motors, capacitor, and contactor will eventually wear out and may need replacing before the end of the system’s service life.

Your system may also develop a refrigerant leak, which is hazardous to your health if it’s located inside. These leaks may occur in the refrigerant lines, at the compressor, or at either the evaporator or condensing coils.

People around Tucson have relied on D&H Air Conditioning & Heating for AC installation, maintenance, and repair since 1959. Our technicians are also experts in heating installation, maintenance, and repair—not to mention indoor air quality. Call to schedule your air conditioner repair or new system consultation with our team today.