With a central air conditioner, cooling down your Bountiful, UT home is as easy as turning your HVAC system on and adjusting its thermostat setting. However, a lot goes on during the cooling process to create the indoor conditions you want. Understanding the science behind air conditioning makes it easy to identify developing problems, troubleshoot minor issues, and perform essential AC maintenance. The following is everything you need to know about the science behind AC.
The Anatomy of an Air Conditioner
Central air conditioners have two primary components: indoor air handlers and outdoor condenser units. Air handlers have evaporator coils and blower fans. Outdoor condensers hold AC compressors, condenser coils, and their own blower fans. Refrigerant travels between these two units to facilitate the heat transfer process. Rather than producing cool air, your air conditioner extracts heat from the warm air inside your home and routes it outside.
AC Refrigerant: The Lifeblood of Residential Cooling Systems
You can liken many of your air conditioner’s primary components to various body parts. AC refrigerant is often referred to as the lifeblood of cooling systems. It enters indoor air handling units as an icy liquid and exits them as a hot vapor gas. During each cooling cycle, your AC compressor pressurizes or depressurizes refrigerant to move it throughout the system, much like a heart.
The Movement of Refrigerant During the Cooling Cycle
When your AC kicks into action, it draws in warm air from the building interior. It passes this air over its evaporator coil, and the icy refrigerant within this coil removes its heat. This same air is distributed throughout the building via ducting to lower your home’s internal temperature by several degrees.
After having absorbed heat, cold refrigerant becomes a high-pressure gas. It’s moved to the compressor while cooled and compressed back into a liquid state. This compression produces condensation that’s routed out of the building via a condensate drain.
With each cooling cycle, the temperature in the interior of your home goes down. Most air conditioners run cooling cycles that last 15 to 20 minutes. However, some highly efficient air conditioners can accomplish the same work within 10 to 15 minutes. On hot, muggy days, your AC can run two to three cooling cycles every hour.
Short and Prolonged Cooling Cycles
If your AC cooling cycles last 25 minutes or more, there’s a good chance that your air conditioner is too small for its service area or needs maintenance. If it rapidly cycles off and on and runs more than five cooling cycles every hour, it may be too large. Short, frequent cooling cycles can also indicate the need for AC maintenance.
Humidity Control
All air conditioners offer three-pronged climate control. Residential cooling systems lower indoor temperatures, remove airborne particulates and extract excess moisture. Dry air tends to feel much cooler than humid air. If the air inside your home feels damp, heavy, or downright oppressive, there may be problems along your AC condensate drain line.
When compressing refrigerant and extracting moisture from conditioned air, air conditioners route condensation along this line and down a condensate drain. If this drain is blocked or clogged, your air conditioner might short cycle, overheat, or simply fail to create the indoor conditions you want. Blocked condensate drain lines can leave homes feeling clammy or muggy and hotter than they are.
Unfortunately, residential air conditioners tend to develop thick growths of algae or algal blooms along their drain lines, in their drain pans, and in condensate drains. These features can also get clogged by slimy coatings of bacteria-ridden biofilm. Problems like these are most likely during air conditioners’ seasonal dormancy periods, especially when ACs don’t receive regular preventative maintenance.
Why Air Filtration Matters
Many homeowners mistakenly believe that their HVAC air filters exist to promote acceptable indoor air quality (IAQ). In reality, AC manufacturers install these components to protect their equipment. The IAQ benefits provided by clean, high-functioning air filters are secondary. These components extract large-sized particulates floating in the indoor air that would otherwise land on sensitive, internal AC components.
AC filters extract:
- Carpet and textile fibers
- Dust
- Dander
- Pollen
- Pet and human hair
Failing to change your AC air filter can inhibit the movement of air throughout your air conditioner. Like blocked condensate drains, dirty filters can lead to problems like short cycling, insufficient cooling, overheating, and excess humidity. Moreover, the airborne particulates that filters extract can settle on evaporator coils.
Dirty evaporator coils have a hard time extracting heat as air moves over them. This keeps refrigerant in an icy, liquid state and can cause air conditioners to ice over and freeze.
Blockages at the AC Condenser Unit
While excess moisture is routed out of buildings via the AC condensate drain, extracted heat is released outside via the outdoor condenser unit. This component is typically installed on a concrete or composite pad in a back or side yard. To ensure the release of heat, it should always have at least 24 inches of clearance on all sides. If your condenser has been encroached upon by fast-growing bushes, grass, or weeds, the hot air your air conditioner routes outdoors could become trapped. This can also result in overheating and may cause your air conditioner to shut down.
Your Thermostat’s Role in the Cooling Process
Even if all of your air conditioner’s components are working as they should, your cooling system will never turn on and kick into action if your thermostat is broken or isn’t reading indoor temperatures accurately. Standard, central HVAC systems have a single thermostat in a central, neutral location. When these devices register indoor temperatures as being higher than the temperatures that residents have set, they send signals to air conditioners that initiate cooling cycles.
During annual preventative maintenance, we inspect, test, and calibrate thermostats. This way, they’re guaranteed to read indoor temperatures accurately.
The Science of BTUs
When choosing a new air conditioner, the first and most important factor to consider is its size or cooling capacity. The cooling capacity of ACs is measured in British Thermal Units or BTUs.
Many decades ago, people cooled their homes with blocks of ice. To melt a ton or tonne of ice, you’d need 12,000 BTUs. To melt one pound of ice, it takes just 143. Although home cooling technologies have significantly evolved since this time, BTUs remain the universal measurement for AC cooling capacity.
To determine how many BTUs are necessary for cooling your home, you’ll have to account for the amount of space that requires temperature control or your targeted service area. There are lots of online charts that recommend AC sizes or cooling capacities based on square footage alone. However, we use the Manual J Load Calculation to ensure that air conditioners aren’t too large or too small for their service areas. This calculation accounts for a variety of additional factors, including:
- Insulation amounts
- Ceiling heights
- Window sizes
- Number of building residents
- Building layouts
The Manual J Load Calculation is so complex that we leverage special software as part of the AC sizing process.
We help Bountiful, UT, residents get the most from their home cooling equipment. We offer exceptional heating, cooling, and plumbing services. We also provide cutting-edge indoor air quality improvements, ductwork, and HVAC preventative maintenance plans. To find out more about the science of air conditioning or schedule an appointment, contact Blue Best Plumbing, Heating, Air, Generators now.
