In this article…
- 13 Parts Included In A Full HVAC System Replacement
- Outdoor Condenser Unit
- Evaporator Coil
- Furance
- Heat Exchanger
- Air Handler
- Refrigerant Lines
- Ductwork
- Plenum
- Thermostat
- Electrical Disconnect & Wiring
- Condensate Drain Line & Pump
- Expansion Valve
- Dampers
- Additional Components
- How Much Does A Full HVAC System Replacement Cost?
Before investing in any major home upgrade, understanding all that comes with it is essential to know what exactly you’re getting into and if it’s worth it.
When it comes to replacing your HVAC system, there are several components that make up the entire unit, not just the outdoor condenser and indoor furnace or heat pump.
A full HVAC system replacement is a large purchase, and you want to know all that goes into the installation in order to choose the best company to work with.
At Wright Home Services, we’ve been providing San Antonio homeowners with high-quality HVAC services, repairs, and full system replacements since 1979.
On top of our premium services and products, we’re here to educate you on all things heating and cooling. This includes teaching you the parts of an HVAC system, what they do, and what is included in a full system replacement.
This article will outline what’s included in a full HVAC system replacement along with what additions are common, like IAQ upgrades, when updating your system.
Then, you will be more prepared for your replacement project and can find a trustworthy HVAC company.
13 Parts Included In A Full HVAC System Replacement
The compressor, furnace, and air handler (in heat pump systems) are the main units you know of that make up an HVAC system. You have an indoor unit and an outdoor unit, right?
While this is true, there are many other important components that are responsible for the proper functioning of your AC.
Here are the 13 main parts of an HVAC system typically included during a full system replacement.
1. Outdoor Condenser Unit (AC or Heat Pump)
The condenser is the outdoor part of the cooling system. It releases the heat absorbed from inside the home into the outside air to cool the home.
Over time, the condenser’s compressor and coils wear down, causing reduced efficiency, refrigerant leaks, or complete failure. Newer models are more energy-efficient and use eco-friendly refrigerants.
2. Evaporator Coil
The evaporator coil is located inside the air handler or furnace and works to remove humidity from the air as the refrigerant circulates through it, bringing cooler, drier air into your home. This process cools the air before it is pushed through the duct system.
Coils can become corroded or clogged with dirt over time, reducing the capacity and efficiency and the ability to remove heat and humidity from the home.
If the coil leaks refrigerant, it must be replaced. A leaky evaporator coil is not only costly to repair over and over again, but leaking refrigerant is also not good for the health of your home and the environment.
3. Furnace
The furnace generates heat using gas, propane, or electricity and distributes it throughout the home through the ductwork, and they typically last 15-20 years.
If the heat exchanger cracks, it can release carbon monoxide, making replacement necessary. Older furnaces are also far less efficient than newer models, so upgrading will help reduce energy bills and keep your indoor air temperature more consistent.
4. Heat Exchanger
This is the part of the furnace that transfers heat from the burners to the air without mixing dangerous gases into the home’s air supply.
A cracked heat exchanger is dangerous because it can leak carbon monoxide into the home. Since it’s a critical component of the furnace, replacing the entire furnace is often the best option once it wears out.
5. Air Handler (for heat pump systems or electric systems)
For a heat pump or electric heating, the air handler replaces the furnace. It houses the blower motor that moves air through the duct system and usually contains an electric heating element.
Blower motors can wear out, reducing airflow. If the unit is inefficient, it can cause excessive energy use and uneven temperatures throughout the home.
6. Refrigerant Lines
Refrigerant lines are insulated copper pipes that carry refrigerant between the indoor evaporator coil and the outdoor condenser, facilitating the heating or cooling process.
Old refrigerant lines can develop leaks, extremely reducing efficiency. If the system is being upgraded to use a newer refrigerant type (such as R-454B instead of 410A or R-22), the lines may need to be replaced to match the new refrigerant.
7. Ductwork (if needed)
Ductwork is an essential component of your HVAC system and is responsible for carrying the heated or cooled air from the system to different parts of the home.
Ductwork does not always need repairing or replacing. However, if ducts are old, leaky, or improperly sized, they can lead to energy loss, reduced airflow, and inconsistent temperatures.
If your ducts are over a decade old and haven’t been repaired or resealed, sealing or replacing ducts will significantly improve the system’s efficiency.
Duct design (like many things) has changed over the years. The design from past builders can be very basic, while today we design ductwork to improve efficiency, comfort, and indoor air quality.
8. Plenum
The plenum is a large air distribution box that connects the HVAC unit to the ductwork, directing airflow properly.
If the plenum is leaking, poorly designed, or has microbial growth, it can reduce the overall performance, efficiency, and indoor air quality of the system. Upgrading it is crucial for proper airflow and efficiency.
The plenums we use today have a much higher R value (insulation) and have an anti-microbial liner to prevent growth in dark, humid environments.
9. Thermostat
The thermostat controls the HVAC system and, while not necessary, is typically updated along with a new HVAC system.
Older thermostats are less efficient and lack features like programmable settings, smart home integration, and Wi-Fi control. Replacing with a smart thermostat can lead to significant energy savings and enhanced comfort.
Some smart thermostats also have geofencing for no-need programming. This means you can program your thermostat to know when you are away to set the temperature higher or lower to conserve energy and improve efficiency.
10. Electrical Disconnect & Wiring
The electrical disconnect is a safety switch that allows power to be cut off to the outdoor unit for servicing.
Faulty or outdated wiring can be a fire hazard or cause the system to have an electrical fault. New installations require updated electrical components to meet safety codes.
When installing these components, it’s crucial to make sure the disconnects are sealed or weatherproofed to keep out rain and bugs.
11. Condensate Drain Line & Pump
The condensate drain line removes moisture that inevitably forms during the cooling process. The pump helps move the water if gravity drainage isn’t possible.
Clogged or cracked drain lines can cause water damage and microbial growth, which affects your indoor air quality and allergies. A failing pump can lead to water backing up into the HVAC system and flooding.
12. Expansion Valve (TXV or EXV)
The expansion valve regulates the flow of refrigerant into the evaporator coil, ensuring efficient cooling.
A failing valve can cause uneven cooling, inefficient operation, or freezing of the evaporator coil, whereas newer TXVs improve efficiency and performance.
13. Dampers (for zoned systems)
Dampers regulate airflow within ductwork, allowing temperature control for different zones of the home.
Broken or stuck dampers can lead to uneven heating and cooling throughout the home, and replacing them will restore balanced airflow in a zoned system.
Additional Components Included In An HVAC Replacement
The above-listed elements are typically necessary and common for all full HVAC replacements. But there are additional upgrades that you may want (or need) depending on the condition of your system and its efficiency.
Some other parts of your HVAC system that may need replacing include:
- Air Filtration System – May include a standard filter, media filter, or electronic air cleaner for improved indoor air quality.
- Dehumidifier – Optional additions to reduce indoor humidity levels.
- UV Light System – Helps eliminate bacteria, mold, and allergens from the air.
- Surge Protector – Protects the HVAC system from power surges.
- Insulation for Refrigerant Lines – Ensures efficiency and prevents condensation issues.
- Ventilation System (if required) – Includes components like fresh air intakes or energy recovery ventilators (ERVs) for better indoor air quality.
- New Registers & Grilles (if needed) – These can be updated for better airflow and aesthetics.
Every HVAC system installation is unique because every home is different. Depending on your home’s layout and your system’s current condition, the cost for a replacement will vary.
How Much Does A Full HVAC System Replacement Cost?
Now you know all the standard parts included in an HVAC replacement along with common additions you may need and have a basic understanding of what goes into your replacement project.
Knowing the components of an HVAC system and what is included in a replacement will help you to choose the right company to work with and avoid potentially getting ripped off by a faulty company.
Even if you choose the highest quality products, if they are not installed correctly, they won’t perform as they should.
As soon as your new system is installed, the first day of its life is the most important. It will tell you if your system was installed properly, and any potential issues will come to a head.
The last thing you want is to waste thousands of dollars for a faulty installation, which is why understanding the installation process and what’s included is essential.
Knowing all that goes into your HVAC replacement is the first step to understanding how much it will cost — because every project is different.
The cost of a full HVAC system replacement can range anywhere from $8,000 at the lower end to upwards of $20,000, depending on the system type, size, and any upgrades or modifications.
When it comes to any home upgrade, knowing all that goes into your project is the first step to success. The more you are educated on products, installation practices, and cost, the better prepared you are to find the right company to work with.
To help you move forward with your HVAC replacement project and fully understand all that goes into the price, check out this article that details how much an HVAC system replacement costs, what factors most influence that cost, and how to find the right company for you.
Ready To Upgrade Your HVAC System With A Company You Can Trust?
Wright Home Services has helped thousands of homeowners in the San Antonio area upgrade their old, worn-out HVAC systems and improve their home’s comfort with efficient IAQ additions.
Our team of expert, certified technicians and installers put care into their craftsmanship with every installation, and we’ve been doing it Wright since 1979.
Treating people Wright – since 1979!
