Emergency service needed? We're ready to help! Request Service


Air Conditioning 101: Everything You Need to Know

Air Conditioning 101 Everything You Need to Know

Overheated people tend to not be very productive. We don’t typically have long hot and humid summers here in the Pacific Northwest, but we often have some solid above 80 degree months. Hot kitchens, stuffy bedrooms, or stifling offices sap our reserves and make it hard for anyone to function.

Whether you are trying to make your home comfortable or want to offer a cool oasis for your employees and customers, installing air conditioning is an investment in better health. In this air conditioning guide, we’ll cover all the major topics:

Keep reading to learn more about air conditioners, and to have your questions answered!

How Does an Air Conditioner Work

Willis Carrier invented the first modern air conditioning system in 1902. Willis’s invention led to increased production in manufacturing and became the start of summer movie blockbusters.

Popcorn and an ice-cool movie theater – there is no better way to cool off! People soon learned that precisely controlling indoor temperature and humidity offers some pretty great advantages. Everything from malls to homes became a place for people to enjoy life in comfort.

But how does an air conditioner work?

The Basics of Air Conditioning

Air conditioners have three main components: a compressor, a condenser coil, and an evaporator coil. They also have a special chemical called refrigerant that loops through the system absorbing and removing heat. Working together these three components convert the refrigerant from gas to liquid and back to gas quickly. 

What are Refrigerants?

Refrigerants have a pretty cool superpower – the power to go back and forth from a liquid to a gas very easily which makes them very useful in the air conditioning system. From high school chemistry (or boiling water on the stove) you know how liquid water evaporates into a gas – steam- when it is heated to the right temperature.

Refrigerants do the same thing – when they are in the liquid state they absorb heat, transforming into a gas. In the air conditioning system, the refrigerant is then forced to return to being a liquid causing it to expel the heat outside, and back it goes into the house to grab more heat to remove. 

Where Does an Air Conditioner Pull Air From?

To cool off the inside of our homes or buildings the heat inside needs to go outside. Seems simple. And in some ways it is. This is the job of the blower and evaporator. As the warm air from your home is blown across the evaporator coils the refrigerant in the coil absorbs the heat turning it from a cold liquid to a hot vapor.

This whole process happens quickly, cooling the air in your home while the hot vaporized refrigerant dumps the absorbed heat outside through the efforts of the compressor and condenser. 

What is an Air Conditioner Compressor and Condenser?

The compressor and condenser work together in an outside unit (or on the roof of a business).

The compressors’ job is exactly that –  to compress or raise the pressure and temperature on the refrigerant gas. The hot pressurized gas then is sent to flow through the condenser where condensation occurs. The heat dissipates into the air, often with the help of a fan, and the refrigerant gas is condensed back into a liquid state to start the whole process over again. 

What Part of the Air Conditioning Unit Helps to Clean the Air?

Let’s take a step back and look at the whole process in motion. Thermostats in our home are the central brain of the operation, telling the system when the temperature needs to be raised or lowered. When the thermostat senses that the room air temperature is too high it sends a message to the system to start the cooling process. 

A fan pulls the hot air into air ducts where it is passed through a filter system that removes airborne particles like dust and lint. The warm filtered air then flows over the evaporator coil where the refrigerant absorbs the heat and the indoor air is cooled. A fan then pumps the cooled air back through the ductwork into the various rooms. 

Meanwhile, the refrigerant has been converted to a gas and travels outside where the compressor pressurizes the gas and sends it to the condenser coil. Here the outdoor fan disperses the heat into the outdoor air and the refrigerant becomes a liquid and goes back through the cycle again. 

Types of Air Conditioners

The reason Willis Carrier invented air conditioning was to control humidity. Carrier was given the challenge to find a solution to humidity problems plaguing a New York printer. Humidity was causing poor production quality, lost production days, and threatening their production schedule. Besides causing problems in printing and manufacturing, humidity – water vapor in the air – prevents our bodies from regulating our body’s temperature.

Fortunately for us, Carrier took the challenge and today’s air conditioning units are a result of that first goal – conditioning rooms by dehumidifying the air which makes spaces feel cooler to the skin. Modern air conditioners come in a variety of shapes and sizes to help regulate both humidity and heat in your home or business to keep everyone cool and comfortable.  

What are the Different Types of Air Conditioners?

The type of air conditioner that is right for you and your home depends on a variety of factors –  size, physical location, and the way you use it are the main considerations. Let’s review the main types of air conditioners and the pros and cons of each. 

Central Air Conditioner

Central Air Conditioner

As the most common type of systems in the United States, central air conditioners are good for those who have larger homes and want to cool multiple rooms at once. A duct system throughout the home keeps the entire house consistent with no warm or cold spots. This system also uses air filters to improve indoor air quality and remove dust, pollen, and airborne particles. Central air conditioners work in conjunction with existing furnace systems – no need for new ductwork.  

Why Choose a Central Air Conditioning System

Central air conditioners are more efficient and quieter than room air conditioners. Because they take up less room and are, well – centralized –  in an out of the way space, central air conditioning systems keep your house decor clean. 

Ductless Air Conditioner

Ductless Air Conditioner

Ductless mini-split systems work exactly like the central system but without the ducts. Split systems have two units – one on the outside of the home and one inside the room. Because there are no ducts each unit must be installed in individual rooms. 

Why Choose a Ductless Air Conditioning System

When considering a system for your home the deciding factor often is the need for ductwork. These ductless air conditioning systems tend to be more energy-efficient and are easier to add to older or smaller homes that do not have the space for ductwork.

Additional reading: Ductless Mini Split vs Central Air: A Quick Comparison

Heat Pumps

Heat Pump

A heat pump combines heating and air conditioning all in one unit. There are multiple fuel options for heat pumps – gas, electric, and dual-fuel. Heat pumps pull heat out of the outside air to heat your home and reverse the process when cooling your home. Heat pumps are great for areas that have a mild climate. 

Why Choose a Heat Pump System

As an economical source of heat (air is free!), heat pumps can’t be beaten. But when it is freezing or below you will need a backup heating system. If you have a lot of freezing days in your area then a heat pump isn’t a good option. An investment in a heat pump can help you save money on heating costs and lets you heat with renewable electricity.

Additional reading: Heat Pump vs Air Conditioner: Which is Right for You?

How to Choose an Air Conditioner for your Home?

Choosing an air conditioner for your home comes down to a few things:

  • Size of your home
  • Budget
  • Ductwork
  • Energy-efficiency
  • Other considerations 

The first step of choosing an air conditioner is determining what you’re willing to spend and how much effort it will be to install. If you are in an older home that doesn’t have ductwork, that may be the deciding factor. For new homes, you will have the luxury of planning a system before you build. If you are replacing an older system, check to make sure that your new system has a good warranty and that it is professionally sized for your home.

What Size Air Conditioner Do I Need?

Properly sizing your air conditioner for your home is key to both energy efficiency

and adequate cooling. Too small an air conditioning system will not keep your home comfortable on the hottest days and too large of a system won’t remove humidity efficiently.

This may seem counterintuitive but when a too-large system cycles on and off too often it never fully dehumidifies your home keeping you sticky and irritated.  

How to measure what size air conditioner you need?

An improperly sized conditioner will consume more energy and wear out quickly. As a general rule, you want about 15 to 25 BTUs of cooling power per square foot. However, there are many factors that go into sizing that it’s best to speak with a professional – it’s their job!

You can do the calculations for yourself so when you speak to a professional you are armed with the basic info you need. The recommended BTUs vary based on ceiling height, windows and doors, insulation, and how much sun your home gets but you can find the general basics through some simple math.

Related: AC Sizes Explained: What Size Air Conditioner Do I Need?

Air Conditioner Cost for Installation or Replacement

There isn’t one answer to how much a new air conditioner will cost. The cost nationally varies on geographical region. In the Northwest central air conditioning system can range from $5,000 to $10,000. Because your system will have a bearing on your bills and comfort for years, trusted HVAC experts will help guide you to the best system for your home.

If you are adding a system to your home, having your ductwork inspected is highly recommended. Depending on what is needed – leaky ducts, damaged ducts from animals, undersized or oversized ductwork – repairing existing ductwork can bump the cost by an extra $1,500 to $5,000. Remember that the average life of an air conditioning system is about 15 to 20 years. The newer systems are more energy-efficient offering savings on your bills over their lifetime.

How to Get a Quote on a New Heating and Cooling System

Getting a quote should be an easy process. HVAC professionals are ready to help you find the best system for your home. Our consultants at Jacobs love helping so reach out to us with any questions. We can come out to your home and evaluate the size, ceilings, windows, and existing system and discuss options. 

Troubleshooting Your Air Conditioner

We often don’t think about our air conditioning until it isn’t working. You can do some investigative work yourself before calling in a professional. There are a few prevalent problems that we see often. 

Thermostat Not Set Correctly

The first thing to check is your thermostat. Make sure that it is in AC mode and the temperature is set correctly. A thermostat that is directly in the sun can also malfunction and register the wrong indoor temperature. Also, thermostats that are near the kitchen and other heating or cooling sources such as vents or windows can be a factor. 

Clogged Filters

Also, check the filter of the air conditioning system. Clogged filters can be a problem that blocks airflow through your system. When air filters get dirty the air conditioner has to work harder, increasing operating costs and leading to costly repairs and shortening the life expectancy of the unit. 

Plants Crowding the Outdoor Unit

The outdoor units of air conditioners need adequate airflow. Make sure that there are 2 to 3 feet of clear space around the outdoor unit. Plants and trees that crowd or overhang your compressor will make it struggle to do its work, eventually burning it out. 

Air Conditioner Maintenance

The number one reason air conditioners stop working before their time is lack of regular maintenance. Regular inspections catch problems before they get worse and cause a big bill. Technicians will come and check filters, unit parts, and refrigerant to make sure that all is working well so you don’t have a summer heat emergency.

Additional reading: When to Service Your Air Conditioner (And How Often)

How Jacobs Can Help

If you are looking for a new air conditioning system, our consultants at Jacobs Heating & Air Conditioning will evaluate your home and help find the best system for your lifestyle. If you need air conditioning maintenance we are ready to help you save money and keep surprise breakdowns away. You can schedule your next tune-up and keep the stress and hassle out of maintaining your system. No matter what you need we’re always just a phone call away. You are welcome to review our statement on COVID-19 and how we’re taking precautions to protect you, our team, and our communities.

About the Author

Amanda Jacobs portrait

Amanda Jacobs, Internal Project Manager

Amanda Jacobs is an Internal Projects Manager and 3rd generation member of Jacobs Heating & Air Conditioning. She received her MBA from Seattle University and has worked for a leading HVAC training and consulting firm. When not talking HVAC on the Jacobs Blog, you can find her on the golf course or whipping up her famous vegan chili.