How Your Home Air Conditioning System Works

Pictured above is a typical split system design found in most Atlanta, GA homes. It includes an air conditioner located outside the home and a furnace located inside, along with the other equipment that make the magic happen such as indoor air quality products.


We hope the information below helps you understand how your air conditioning system operates. For more information about efficient air conditioner and heat pump solutions for your home, visit our site at: Atlanta Air Conditioning.

The Split System Air Conditioning Process:

1) Refrigerant is cooled. Once the thermostat registers that indoor air is too warm, the air conditioner (or heat pump) kicks in and compresses refrigerant. Compressing refrigerant releases the heat and chills it. The chilled refrigerant is sent back inside to the indoor coil, typically called an evaporator coil. The efficiency of an air conditioner or heat pump (cooling) is measured with a Seasonal Energy Efficiency Rating (SEER).


2) Fan pulls air from the home. The furnace fan or fan coil (air handler) pulls air from the home through the return air duct. Yes, even in the cooling season, your furnace is used. A variable speed fan offers quieter, more efficient operation.


3) Air is filtered. Return air is filtered before entering the air conditioning system. Advanced air cleaners can filter microscopic particles and viruses out of the air keeping your home healthy and your system very clean which helps with efficiency and reliability.


4) Air is cooled. The filtered air is then pushed through the coil system by the fan motor. The cold refrigerant in the evaporator coil absorbs heat and causes moisture to condense, thus cooling and dehumidifying the air. This conditioned air is pushed on by the fan while the heated refrigerant is sent back outside to the air conditioner (or heat pump). The heated refrigerant is pressurized again to remove the heat.


5) Mold is killed & coil efficiency kept high. In the damp interior of an evaporator coil, mold will grow which affects not only the health of your family (mold spores in the air), but the efficiency of your system. In the example layout above, a UV lamp is mounted within the coils to prevent this. UV light kills mold keeping your system efficient and healthy.


6) Cooled air sent back into the home. After leaving the evaporator coil, the cool, dehumidified air is pushed back into the home. In extremely humid climates, a separate whole house dehumidifier can be installed to further remove humidity from the conditioned air.


7) Air is exchanged. At the top left of the above system layout sits a ventilator. Ventilators are part of complete indoor air quality solutions. They exchange fresh outdoor air for stale indoor air. A ventilator is able to do this with minimal loss of energy, retaining the cooled and dehumidifed air your Air Conditioning system worked hard to produce!



The Split System Heating Process:

Gas Furnace:

1) Heat exchanger is heated. A heat exchanger is a type of metal grid that air passes through, and it is heated by the gas powered flames once the thermostat registers indoor air as being too cold.


2) Fan pulls air from the home. The fan in your system pulls air from the home through the return air duct. A variable speed fan is quieter, more efficient and provides a more comfortable climate.


3) Air is filtered. Return air is filtered before entering the system. Advanced air cleaners can filter microscopic particles and viruses out of the air keeping your home healthy and your Air Conditioning system very clean which helps with system life and efficiency.


4) Air is heated. The air is then pushed over the heat exchanger by the fan motor.


5) Humidity is added back. A heat exchanger dries out winter air even more. A whole home humidifier replenishes needed moisture for a healthier home. Restored humidity also helps the air feel warmer, thus decreasing the energy needed during the winter to feel warm and comfortable.


6) Heated air sent back into the home. The fan forces the heated air back into the home via installed ductwork.


7) Air is exchanged. At the top left of the above system layout sits a ventilator. Ventilators are part of complete indoor air quality solutions as they exchange fresh outdoor air for stale indoor air. A ventilator is able to do this with minimal loss of energy, retaining the warm, humidified air your system worked hard to produce!

Heat Pump:

1) Heat Pump is engaged: When the thermostat registers the need for warm air the heat pump turns on and begins extracting heat energy from the outside air. Even when it is cold outside, air contains a certain amount of heat energy. A heat pump absorbs this energy into the refrigerant, and then sends the heated refrigerant back inside.


2) Fan pulls air from the home. The fan in your fan coil (air handler) pulls air from the home through the return air duct.


3) The air is filtered. As with the first method, an advanced air cleaner filters out micro scopic dust and organisms.


4) *Coil difference: When using a furnace and air conditioner, the indoor coil is separate, and called an evaporator coil. When using a heat pump only, the indoor coil is called a fan coil, and is basically a combination of the furnace fan and the evaporator coil.


5) Air is heated. The air is then pushed through the coil system by the fan motor. The heated refrigerant warms the passing air and then is cycled back outside to the heat pump.


6) Mold is killed & coil efficiency kept high. In the damp interior of an evaporator coil, mold will grow which affects not only the health of your family (mold spores in the air), but the efficiency of your system. In the example layout above, a UV lamp is mounted within the coils to prevent this. UV light kills mold keeping your system efficient and healthy.


7) Heated air sent back into the home. After leaving the indoor coil, warm air is pushed back into the home. In dry winter climates, a separate whole house humidifier can be installed to replenish the humidity in indoor air.


8) Air is exchanged. At the top left of the above system layout sits a ventilator. Ventilators are part of complete indoor air quality solutions. They exchange fresh outdoor air for stale indoor air. A ventilator is able to do this with minimal loss of energy, retaining the cooled and dehumidifed air your system worked hard to produce!

Hybrid Heating System:

A hybrid system uses both a furnace and a heat pump. Heat pumps can be more efficient than a gas furnace at certain temperatures in areas where fuel prices are high. Heat pumps cannot provide adequate heat however in extreme cold, and their efficiency drops substantially at that point.


A smart thermostat is used to control a hybrid heating setup. It intelligently switches between units for the highest energy efficiency available depending on the outside temperature.



Thank you for reading our blog! More great information will come soon. You can visit our website at: Atlanta Air Conditioning Contractor

Indoor Air Quality Part IV: Whole House Humidifier

Welcome to Part IV of our Indoor Air Quality series. Today we discuss whole house humidifiers. A whole house humidifier or whole house dehumidifier can be a life saver if you are in climates with any type of humidity extreme. Whether a cold, dry Chicago Winter or a hot and humid Georgia summer season. This fourth part of the indoor air quality product suite is definitely key.



Whole House Humidifier
When the Winter climate is dry Winter, a whole house humidifier can be the end to itchy dry skin. It can also avoid damage to instruments and wood furniture, static electricity and other discomforts. A whole house humidifier is installed onto your HVAC system, and adds humidity to the air leaving your furnace (or air handler). There are different types of humidifiers including fan powered, bypass and even steam humidifiers.

There are two primary types of whole home humidifiers: powered and bypass. A Bypass Humidifier is installed before the furnace, on the return air ducting, and has a bypass pipe that is attached to the "warm air" or "supply" duct. A bypass humidifier doesn't have a fan, so it takes the forced air leaving the furnace and uses that to flow through the humidifier. Obviously, if your furnace is crammed in a closet, you might not have room for this setup. A powered humidifier has its own fan which means some electricity used, but they can also out perform a bypass humidifier and don't require the extra installation space. A powered humidifier is mounted on the warm air ducting (never on the cool air return).

Automatic controls: Advanced humidifiers can sample the outdoor air to gauge how they run. A humidifier with automatic control is the best because it will adjust to daytime and nighttime humidity changes. Just because your air needs humidity doesn't mean pumping too much in is healthy either. That introduces other problems. You want a humidifier and control that can keep humidity levels right where they need to be year round.

Another humidifier on the market is a steam humidifier. They can churn through 10-12 gallons of water a day for large homes, but they also required much more power to run. Additionally, for ultra humid climates, whole home dehumidifiers exist to help maintain proper moisture levels.

Whole home humidifiers are tricky to install. If they are not done right you can ruin controls (never mount the humidistat on the hot air return for example), you can loose major performance (if placed on the wrong ducting) and much more. Do your research, but let a pro install it. One technician stated that he has had more business fixing bad humidifier installations than installing new ones. Don't be a statistic!

Whole House Dehumidifier
An air conditioning system dehumidifies indoor air as it cools it, because moisture condensates on the frigid piping in the indoor coil as the warm indoor air passes through. However, a whole house dehumidifier can step it up a notch, and for our humid Atlanta summer weather, that can be nice. Similar to a whole house humidifier, a dehumidifier integrates into your HVAC system, and removes humidity your indoor air as it passes through your cooling system.

For more information on our HVAC service please visit Atlanta Heating & Air Conditioning.

Thank you for reading our four part series on indoor air quality! We know these products will transform the health and comfort of your home. Call us at (770) 860-1837 for more information!

Indoor Air Quality Part 3: Ventilators

Welcome to part three of indoor air quality products from your Atlanta HVAC Contractor! Today we are reviewing the benefits of a Ventilator. Warning: you'll probably want one of these after reading.

*As mentioned in the previous Zack hammonds indoor air quality articles, no indoor air quality components are mutually exclusive. If you want to really harness the power given to you by modern air purification technology, you have to consider them all.

Ventilators (ERV and HRV)

Have you ever stunk up the house with food or old garbage? Been worried about CO2 buildup, or other airborne pollutants like cleaning products that get recycled through your HVAC system? What's the answer? Open the windows right? But let's say it is 100 degrees outside with crazy high humidity - in other words, a normal Atlanta summer - opening windows isn't the best for the utility bill. If it is freezing outside, you again don't want warm air funneling out an open window. The answer? A ventilator. Ventilators takes the stale air from inside your home, and exchange it with fresh air from outside. During the exchange, the cooled air that is passing out is used to cool the air coming in....the energy is exchanged. Not flawless, but very energy efficient. With a ventilator, you can bring fresh air inside during the middle of a hot Atlanta summer without killing your air conditioning bill. The same is true for the Winter season.

There are two types of ventilators: Heat Recovery Ventilators (HRV) and Energy Recovery Ventilators (ERV). The latter exchanges humidity as well as heating and cooling energy. So if you are using a whole home humidifier in the winter, an ERV is the better way to go, to adjust the dry air coming in.

Ventilators sit downstream of your HVAC system. Assuming you have all four indoor air quality (IAQ) product types installed, when air is pulled from your home and heated or cooled, it is first taken through the Advanced Air Cleaner to filter microscopic particles like dust, pollen, toxins and viruses. The next IAQ product the air goes through, or by, is the UV Lamp. Remember, the UV Lamp isn't doing anything to the air. It is killing mold that grows in the damp indoor evaporator or fan coil. After the UV Lamp, the air is humidified or dehumidified, and then we hit the Ventilator. See the image below:

As always, thank you for reading the Zack Hammonds blog! If you need a local HVAC specialist in the Atlanta, GA area, we are your best choice. To read more about us please visit: Atlanta Air Conditioning. We'll see you soon for Part IV of Indoor Air Quality!

Indoor Air Quality Part 2: Advanced Air Cleaners

Welcome back to Indoor Air Quality Part II: Advanced Air Cleaners.

Zack Hammonds is happy to post our IAQ blog part 2 to further educate Atlanta homeowners on the purpose and importance of indoor air quality products.

If this is your first reading, you should catch up with our first IAQ blog post that talks about UV Lamps and how they help the efficiency of your air conditioning system while protecting your home's indoor air from mold. Now we are moving on to advanced air cleaners.

If you are not familiar with the layout of a typical air conditioning and heating system, take a look at the image below. See the bubble identifying the Advanced Air Cleaner. It is installed after the return air duct, and before the furnace (or air handler). Normally there is a small filter that comes with your HVAC system. These filters are thin, and made to just capture larger particles in the air. They do not filter at very high levels.



Remember that the job of a UV Lamp is to kill mold growing in an evaporator coil (or a fan coil). A UV lamp does not clean the air, but protects the air. The job of an advanced air cleaner is to clean & filter the air returning being drawn from your home before it goes back into the HVAC system, and then back into every room of your house.

What are the advantages? We're so glad you asked. Read on:

1) Cleans your indoor air. When we say these air cleaners clean your indoor air, we really mean it. Down to microscopic things like pet dander, chemicals, smoke, and bacteria. Some can even kill the flu virus! Think about that....someone has the flu at home. What does your current system do? It potentially pumps those germs throughout the entire house. Not anymore. Advanced air cleaners are also great ways to remove seasonal allergens from your air.

2) Protects your air conditioning system. An advanced air cleaner keeps your air conditioning and heating system clean and running more efficiently. Every system has a filter - they are typically 2 inches thick and made to be replaced monthly. These filters keep out the big stuff, but are not the ideal choice for really keeping your system clean, and definitely do not do much for indoor air quality.

Measuring the ability of an Air Cleaner

The ability of air cleaners or filters is measured with a Minimum Efficiency Reporting Value (MERV). MERV ratings tell you what an air cleaner is capable of doing. MERV 16 is high end for residential applications. MERV 17-20 is most often found in labs with radioactive or carcinogenetic materials...meaning, not your place. MERV 16 will filter most tobacco smoke, all bacteria, and many other things including hair spray, mold spores, pollen, dust mites and the list continues. Imagine your home with the dust, bacteria and chemicals filtered every time your system turns on. Now that is a great start to pure indoor air.

Another note to consider when using an Advanced Air Cleaner: a variable speed fan motor in your furnace or air handler will also increase your air quality, as these fans control climate and air flow much better than traditional fan motors in older HVAC systems.

Thanks for reading the Zack Hammonds blog! We are your finest choice for Atlanta air conditioning and indoor air quality solutions. Visit our website at Atlanta Air Conditioning.

The next IAQ blog is Indoor Air Quality Part III: Ventilators.

Indoor Air Quality Part 1: UV Lamps

Zack Hammonds is starting a five part series on indoor air quality. Maintaining a healthy home is critical, and something that can be overlooked in many HVAC installations.

The primary thing to take away from this series is this: indoor air quality components all do different things. They are not mutually exclusive. Each component we talk about has a specific purpose that cannot be replaced with another IAQ product.

Indoor Air Quality Part I: UV Lamps

To start this series, we are discussing UV lamps. A homeowner one time, at the mention of a UV lamp said, "I heard those things don't work". Why did he have that perception? Because he wanted a UV lamp to filter air, or do some other indoor air quality task that it was never meant to do. A UV lamp has one purpose: to kill mold in your evaporator coil.

What is an evaporator coil? When running your air conditioner (or heat pump) in the summer, chilled refrigerant is pumped from the air conditioner outside via copper tubing to the evaporator coil inside. The fan in your furnace then pulls air from inside your home, and pushes the air through the chilled copper tubing. The air is cooled and dehumidified as water condenses on the coil. (homes that do not have a furnace typically have a "fan coil" which in a basic sense is a combination of the evaporator coil and the fan from a furnace). More information on this process is available at: Heating & Air Conditioning 101

Now that you understand what an evaporator coil is, let's move back to the UV Lamp. The dark, damp interior of an evaporator coil is a breeding ground for mold. Once mold begins to grow in the coil, air conditioning efficiency drops, and mold spores can be released into your indoor air. A UV lamp mounts inside the coil, and kills mold that tries to grow. This protects your air from mold spores, and helps the indoor cole run efficiently to keep air conditioning bills (and heating bills when using a heat pump) at a minimum.

Thanks for reading the Zack Hammonds blog. Visit Atlanta Heating for more information. The next IAQ topic: Indoor Air Quality Part II: Advanced Air Cleaners.

Change your air filter regularly

Check your filter every month, especially during heavy use months (winter and summer). If the filter looks dirty after a month, change it. At a minimum, change the filter every 3 months. A dirty filter will slow down air flow and make the system work harder to keep you warm or cool - wasting energy. A clean filter will also prevent dust and dirt from building up in the system - leading to expensive maintenance and/or early system failure. If you have any questions please call us at (770) 860-1837

HVAC Tune-up

Don't wait for your heater or your air conditioner to stop working before giving it a tune-up. Instead, get a preventative maintenance agreement with Zack Hammonds, it can save you on your monthly energy costs. In fact, routine HVAC maintenance is vital to efficient, worry-free heating and cooling.

Others may claim they know how to do a tune-up, but get the facts first. Some of these so-called "tune-ups" are nothing more than a basic HVAC system inspection. Nothing compares to our full heating and air conditioning precision tune-ups by our NATE certified technicians. Our tune-ups are so thorough you'll marvel at our expertise, because we care so much about our work.


Advantages/Benefits:

• 10% Discount on service calls
• Priority Service
• Keeps operating efficiencies high and utility bills low
• Helps extend equipment life
• Helps protect against costly failures
• Provides you the convenience of scheduled service on a regular basis
• Gives you peace of mind

A Preventive Maintenance visit Includes:

• Clean/Replace Filters
• Monitor Voltage/Amperage
• Check Operating Temperatures
• Check Refrigerant Level
• Clean Outdoor Coils
• Visually Check for Refrigerant Leaks
• Adjust, Lube & Check Blower Assembly
• Check Indoor Coils
• Check & Adjust Burner/Pilot Assembly
• Tighten Electrical Connections
• Check Condensate and Drain Lines
• Check System for Proper Operation & Safety

Call us today (770) 860-1837 to schedule service!