Contents (Click To Jump)
- 1 How Long Does a Ductless Mini-Split System Last?
- 2 How Does A Ductless Mini-Split System Work?
- 3 What Are The Advantages Of A Ductless Mini Split System?
- 4 What Are The Disadvantages Of A Ductless Mini Split System?
- 5 What Factors Determine How Long a Ductless Air Conditioner Lasts?
- 6 What Are The Signs That You Need a Mini-Split Replacement?
- 7 How Can You Increase The Lifespan Of Ductless Mini Split Systems?
How Long Does a Ductless Mini-Split System Last?
The average lifespan for a ductless mini-split heat pump is 12 to 16 years. However, with proper care and routine maintenance, they can last over 20 years.
Several factors affect heat pumps’ lifespan, and having an understanding of how they work helps mitigate their effects and keep your heat pump running efficiently for years to come.
How Does A Ductless Mini-Split System Work?
Now that we know how long ductless mini-split heat pumps last, let’s discuss how they work next. They have many moving parts which can wear down or fail, which is why maintenance is key in extending the life of your heat pump.
A ductless mini-split system, or mini-split air conditioner, has two main components: the indoor unit (air handler), and the outdoor unit. These components provide ductless heating and cooling for your home. The indoor unit typically mounts on the wall of the room (or zone) that is being conditioned. It blows cool or warm air, depending on the setting, into the space.
The outdoor unit sits outside the home, usually on a concrete pad next to the building. It connects to the indoor unit via refrigerant lines and is responsible for transferring heat to or from the indoor unit.
Ductless mini-split heat pumps are capable of providing both heating and cooling to your home. They work the same way as an air conditioning system and use the vapor-compression refrigeration cycle to transfer heat.
However, one key difference between an AC system and a heat pump is that a heat pump can reverse the direction of the vapor-compression refrigeration cycle to pump heat into the home as well.
Vapor-Compression Refrigeration Cycle Explained
The vapor-compression refrigeration cycle is the core operating principle of air conditioning and all ductless mini-split heat pumps. In simple terms, it is a process that transfers heat from the inside of the home to the outdoors, or vice versa.
It transfers the heat by moving compressed refrigerant in this closed-loop system to various components that connect with refrigerant lines. The refrigerant lines contain either gaseous or liquid refrigerant, which varies in pressure and temperature depending on the stage of the cycle.
Here is an outline of the vapor-compression refrigeration cycle in cooling mode:
Saturated vapor refrigerant is pulled through the compressor (located in the outdoor unit). The compressor then compresses the refrigerant to a higher pressure, which also makes it very hot. This high-pressure, superheated refrigerant then travels to the condenser, where it is cooled.
The superheated refrigerant vapor enters the condenser and fills the outdoor coils, which run across the cooling fins of the outdoor unit. The fan on the top of the condenser pulls air through the fins and cools, and the air absorbs heat from the refrigerant, cooling it. As it cools, the refrigerant condenses from a vapor to a pressurized, saturated liquid.
Thermal Expansion Valve
Now that the refrigerant has cooled off some, it cools further via the thermal expansion valve (TEV). The TEV provides a sudden reduction in pressure by increasing the volume of the chamber. Because of the rapid pressure drop, the refrigerant rapidly cools and transitions to a vapor before traveling to the indoor unit.
The refrigerant, which is now very cold after experiencing its pressure drop, travels to the evaporator coils inside the indoor unit. The cold refrigerant fills the evaporator coils, and warm indoor air blows through them. During this time, the refrigerant absorbs the heat from the indoor air, cooling it. The cool air blows back into the room, lowering its temperature.
After absorbing heat from the indoors, the refrigerant returns to the compressor, completing one journey along the closed-loop system. It will continue to undergo the vapor-compression refrigeration cycle until the thermostat’s setpoint is reached.
What Are The Advantages Of A Ductless Mini Split System?
Ductless mini-split heat pumps are fantastic systems for heating and cooling your home. They are highly versatile devices designed to heat and cool a single zone. However, they can be interconnected with other mini-split heat pumps to provide a home with multi-zone control.
There are many advantages to a mini-split heat pump, but they have some disadvantages as well. Here are the main advantages:
Ductless mini-split heat pumps are incredibly energy-efficient and boast high energy star ratings. Compared to a traditional central air conditioning system and air-source heat pumps, mini-splits have a much higher seasonal energy efficiency ratio (SEER) and annual fuel utilization efficiency (AFUE) ratings.
One of the critical factors in the excellent efficiency of ductless mini-split heat pumps is that they do not experience efficiency losses in the ductwork. As such, they have nearly 100% AFUE ratings in moderate climates and SEER ratings up to almost 30 SEER.
Provide Heating and Cooling
Unlike a window air conditioner, a ductless mini-split heat pump can provide both heating and cooling. This dual-operation design is a huge benefit to homeowners. Instead of paying for two systems (separate heating and cooling) and separate installation costs for each, the upfront costs are dramatically reduced with mini-split systems.
No Ducts Required
If your home does not already have ductwork, installing it would be a significant expense. Depending on the size of your home, the price could range from thousands to tens of thousands of dollars alone. As such, a traditional ducted heating and cooling system is not a cost-effective way to get a new HVAC system in your home.
Since ductless mini-split heat pumps don’t use ductwork, they offer a clear advantage in such cases, thanks to the massive difference in installation costs.
Ductless mini-split heat pumps are one of the simplest HVAC systems to install. The indoor unit is mounted level on the wall, the refrigerant lines and cabling are routed through the wall to the outdoor unit, and the system is powered on.
There’s a bit more to the installation than that, but any HVAC technician will tell you that installing a mini-split is a lot easier than a central air conditioner, air-source heat pump, or a gas furnace.
Did we mention how cost-effective ductless mini-split systems are already? The costs are so much lower, it is worth reiterating. Ductless mini-split heat pumps for a single zone range from $700 to $2,000 depending on size (BTU capacity), with installation costs ranging from $500 to $1,500. For each additional zone, you can expect to pay around $500 to $900 more.
On the other hand, a central AC unit typically costs between $1,600 to $4,200 depending on the capacity and brand, with installation costs ranging from $4,000 to $7,500. Keep in mind this doesn’t include the cost of ductwork installation if your home has no ducts.
What Are The Disadvantages Of A Ductless Mini Split System?
Ductless mini-split heat pumps have plenty of advantages, but they do have some downsides as well. They aren’t as efficient as gas furnaces in extreme cold, and they are limited on the amount of space they can condition with one unit. Here are the disadvantages of mini-split systems:
Higher Energy Bills in Extreme Cold
In lengthy winters with extremely cold weather, heat pumps get less efficient. In fact, for every degree colder it gets, heat pumps lose a bit of efficiency.
The reason for less efficiency during colder weather is simple. Heat pumps work by extracting heat from the air, and when it is colder, the air contains less heat. Even cold air has some heat, unless it’s absolute zero outdoors (-460°F, which is impossible on Earth). However, since colder air has less heat, the efficiency of the heat pump is reduced.
For most ductless mini-split heat pumps, this efficiency loss is most notable at 30°F or lower. This means your heat pump will constantly be running, and your electricity bill will go up when it is 30°F or colder outdoors for extended periods of time. To combat this increased energy usage, you can lower the setpoint on the thermostat, wear layers of clothing, or use supplemental heating.
May Require Supplemental Heating
When it is extremely cold outdoors, a mini-split heat pump becomes less efficient at heating your home, increasing your energy bills. Even if your heat pump is constantly running, it might not be able to keep your home at your desired temperature. For example, if you set your thermostat to 72°F, the heat pump might struggle and only raise the temperature to 63°F.
In this case, if you want your home warmer, you might have to use supplemental heating. This includes but is not limited to the following:
- Electric space heaters
- Baseboard heaters
- Hydronic heating
- Radiant heat systems
- Heated blankets
Supplemental heating systems are helpful and can be turned on when the homeowner desires. However, they do incur an extra energy cost on top of the increased energy consumption of the mini-split heat pump due to its decreased efficiency.
Only Heats and Cools One Zone
Heating and cooling just one zone or room can be viewed as both an advantage and disadvantage depending on the situation. It can be advantageous from an energy use perspective– you only pay to heat and cool the room you are occupying.
On the other hand, if you want to heat and cool more than one space, you will need additional indoor units. If you have more than one zone, each zone has its own thermostat control, which can be a great feature for some, but an inconvenience for others.
Takes Up Wall Space
For those keen on feng shui and interior decor, mounting a sizable indoor unit of a ductless mini-split heat pump may be less than ideal. However, compared to the pricey alternative of installing ductwork throughout the home for a central HVAC system, it’s a concession many homeowners are willing to take.
What Factors Determine How Long a Ductless Air Conditioner Lasts?
Many factors determine how long ductless air conditioners last, such as how often they are used and how well they are maintained. If you want the maximum lifespan of your heat pump, keep a constant eye on these factors:
Routine maintenance is essential in maintaining functionality, and increases the lifespan of ductless heat pumps. Maintenance ensures the heat pump is running smoothly and efficiently. It resolves any issues that could lead to a system failure or a major problem.
Maintenance includes cleaning the air filters and coils, checking the refrigerant levels, oiling the fan and blower along with other moving parts, and ensuring proper draining of the condensate. If these tasks are ignored, they can lead to components overheating, jamming, or grinding against each other.
As you may suspect, these issues can compound and result in major repairs or, worse– complete equipment failures.
Amount of Use
How frequently you use the ductless mini-split system also affects how long it lasts. For example, a mini-split unit that is used 12 months of the year won’t last as long as one used for eight months of the year.
If you live in a climate where you can open your windows to bring your home to a comfortable temperature, do so when you can. You’ll not only extend the life of your ductless mini-split heat pump, but you will also lower your energy bills too. Not to mention, this method is much more environmentally conscious!
Outdoor Weather Conditions
The outdoor conditions where you live play a significant factor in the ductless mini-split heat pump’s life. For example, if you live in a climate zone with extremely hot conditions for half the year, your heat pump may last longer than a unit that experiences less extreme climates.
The reason is that extremely hot and cold temperatures put lots of stress on the mini-split unit.
Let’s face the facts; some brands are just better than others. Brand quality is one main reason the lowest cost systems should be avoided. You get what you pay for with cheap mini-splits, which is usually a far below-average lifespan with countless repairs.
Reputable brands include:
- MRCOOL DIY
What Are The Signs That You Need a Mini-Split Replacement?
There are some clear-cut signs that you might need a replacement mini-split system. However, some are not obvious unless you know what to look for.
Poor Heating and Cooling
If your ductless mini-split heat pump is not reaching the setpoint on your thermostat, you may have an issue that requires a complete replacement of the unit. Or, it might be just a simple repair. Either way, you’ll need to get in touch with an HVAC technician for assistance – give our team a call today if you need help.
When a mini-split system doesn’t turn on, it could be a simple issue like a tripped breaker, blown capacitor, broken inverter, or a failed relay. Unfortunately, it could also be a systemic issue that could necessitate a complete replacement.
If the ductless mini-split heat is riddled with refrigerant leaks in the coils, it is often more economical to replace the mini-split unit rather than repair it.
Costly Repairs and Age
One of the most important factors when weighing a repair against complete replacement is the total cost of the repair and the mini-split system’s age.
A good rule of thumb to follow – if the repair cost is 50% or more of a new unit, get a replacement. Or, if the unit is 15 years or older, consider a replacement even if the repair is less than 50% of a new unit.
How Can You Increase The Lifespan Of Ductless Mini Split Systems?
The best way to increase the lifespan of a ductless mini-split heat pump is to stay up to date on routine maintenance and repairs. If you use your ductless mini-split system year-round, it is best to have maintenance performed twice a year– once before winter and once before summer.
Regular maintenance catches minor issues that could turn into costly failures, and keeps your system running smoothly and efficiently.
Another way to extend the lifespan of your mini-split unit is to give it a break. If the weather outdoors is mild, consider turning off your heat pump and opening the windows. If you leave home for a week or two, turn it off entirely or adjust the setpoint, so it doesn’t run as much.