Two stage vs variable speed AC comparison. Read on to find which air conditioning system is best for you.
Naturally, homeowners do not care about these differences in air conditioners. If the cooling technology is cooling your house, why would you get into the details of at what speed it delivers cool air?
Contact us 24/7 for HVAC services!
That is the wrong way to look at how air conditioners work. There is every reason to look at how a two stage AC system differs from variable speed AC.
The critical question is, how do you know the best option for you? In this article, we look at their differences. Even more importantly, we help you select the most informed decision while shopping for your next AC.
Shall we get straight into business?
What is a Two Stage Air Conditioner
A two stage AC system is also known as a dual stage AC system.
The highlight of this system is that it operates at two different speeds. In simpler terms, it has two different stages.
The first stage is the full blast option, where the unit runs at its maximum capacity. This is suitable for delivering the most cooling throughout your property.
The second running capacity is usually a percentage of the total capacity. The exact percentage will depend on your system, but typically, it is around 60-70% of the maximum capacity. If you want to cool your property but not at full capacity, you can select this setting, but not at full blast.
One-stage air conditioning systems only operate at one full blast capacity. Therefore, dual systems are an evolution of the one stage because they allow you to select the cooling capacity you want.
What is a Variable Speed AC system?
What does a variable speed air conditioner have if one stage has one running capacity and a two stage has two running capacities?
That is right; it has numerous variable settings. A typical variable system can run on 750 different settings! The number of settings will depend on the product you have, which is the idea behind variable speed systems.
You can have your system at full blast, at 80%, 70% or even 25%. It just depends on how much cooling you want.
Two Stage System Benefits
The upfront cost of a two-stage AC system is lower. If you are on a budget and looking to replace your AC system, you are better off going for a two stage than a variable speed system.
A two-stage system is not that inefficient when it comes to energy costs. For instance, you can start the higher setting. Then, after cooling your house, you can turn it down to a lower cooling capacity, say 60%.
If you turn it down to 60%, your AC unit uses 40% less energy to cool your property. This is pretty good. But how does it compare to a variable speed system?
Find out below the benefits of a variable speed AC system.
Variable System Benefits
A variable system is known as the most superior cooling technology. Here are its benefits that set it ahead of other air conditioners.
Maximum Energy Efficiency
Regarding energy consumption, a variable speed AC system is far better than a dual system.
If it is not too hot, you do not need to have your system at 100%. The good thing is that a variable speed lets you select any setting you want. And, you can go as low as 25%.
With 25%, you will maintain a consistent temperature throughout the day. Your system may turn off less than when it is on full blast. This consumes far less energy because your system will not have to start over from scratch so often, a process that consumes too much energy.
Yes, air conditioners use much more energy when turning on and not running.
Stronger Dehumidification Capacity
Variable systems dehumidify your home far better than a two-stage AC system.
The continuous filtering of cold air from the air compressor is behind this stronger humidity control. This feature helps maintain the temperature at all times, keeping humidity levels down.
A variable system will not turn off, ensuring you have desired temperature and humidity levels at all times.
Variable AC system is Quieter
The fact that variable systems run at lower capacities means they are quieter.
Two stage systems are typically quieter than single-stage AC units. However, variable speed systems barely make any noise all through the day.
Have you ever been indoors and felt too cold only to have it feel too hot within 30 minutes. That is one major drawback of single-stage air conditioners, and sometimes even two-stage air conditioners.
Usually, a single or two-stage system may overshoot the thermostat setting and cool it too much. However, the indoor temperature will most likely drop below the set point when it turns off before repeating this cycle.
On the contrary, a variable speed system maintains the indoor temperature to what you have set it. Furthermore, there will be fewer hot and cold points in your house.
May Qualify for Rebates
Certain utility companies and some states offer rebates if you purchase an air conditioner that is highly energy efficient.
Variable speed systems have the best SEER rating. Therefore, they usually qualify for such rebates. These rebates are constantly changing. Therefore, you must check with your utility company, state, or county to see what your AC systems qualify for.
Drawbacks of Variable Speed Air Conditioner
Here are some reasons you may consider a variable speed air conditioner unsuitable.
Higher Upfront Costs
The main downside of variable AC systems is their initial cost. They do not come cheaply. Well, you may cover up for these high upfront costs as it is a more efficient system.
The other drawback of variable speed air conditioners is the repair costs. They have more advanced technology, which is a great thing. However, if you need to repair the AC, you will have to pay more to replace parts and cater to labor costs.
Sometimes, the system is under warranty, and you don’t have to worry about the repair. However, labor costs are not covered in the warranty. You, therefore, want to discuss this with your HVAC technician in advance.
A good compromise would be to go strong on air conditioner maintenance, just to avoid costly repairs.
Might be Overkill
Depending on the climate, buying a variable system may be overkill. If your summers are mild with ideal relative humidity, getting variable speed air conditioners may not be worth the extra price.
If your summers are not that hot, a two stage or even a one stage AC system might be good enough for you.
Still in doubt whether a variable system may be too much for you, feel free to contact the HVAC company near you for recommendations.
Your Home May be Incompatible
If you have a central air conditioning system, replacing it with a variable-speed air conditioner can be easy.
However, you may not want to get variable speed systems if you have uninsulated ducts. This is because they may result in too much condensation.
Variable speed air conditioners run for too long. This may keep your ductworks too cold, which will form condensation. This condensation may start dripping into your walls down through the ceilings.
This excessive moisture can cause water damage and wood rotting in your property. It can also result in mold and mildew growth.
Simply put, if you have uninsulated ductworks, you are better off with a two-stage air conditioner.
Two Stage Vs Variable Speed Air Conditioners: Impact On Air Quality
When we talk about air conditioning, people worry about cooling their houses. However, behind the scenes, your air conditioning unit helps improve indoor air quality.
A variable and a two-stage stage will help keep your air quality better. With both, you will have cleaner air free from pollutants and allergens.
However, a variable speed air conditioner still does so much better at improving your air quality. You do not have to worry about mold growth with a higher dehumidification capacity.
Also, variable-speed air conditioners continually pass the air through the AC filters. The result will always be cleaner and fresher air.
Our Judgements: Which is better, two stage vs variable speed air conditioner
Here is a quick recap of a two-stage unit and variable speed AC systems:
- Two-stage AC units have two settings: 100% running capacity, and another lower capacity, of around 60%
- A variable system has many running settings.
- A two stage system runs for shorter periods but uses more energy
- A variable speed air conditioner runs for longer but uses minimal energy.
- Both systems dehumidify the air. A variable speed system dehumidifies more and is suitable for highly humid environments. On the other hand, a two stage AC system dehumidifies less, therefore suitable for less humid areas.
- Two variable systems are cheaper to buy but more expensive to run. Variable speed systems are expensive to buy but cheaper to operate.
So, which is more suitable for your household? Generally, a variable air conditioner is better than a two stage AC system. And, we would encourage you to get a variable speed system over a two stage system.
The only time a two stage system would be better is when you have a lower upfront budget.
When Should I Upgrade to a New AC unit?
It would be best if you started considering upgrading your air conditioner when:
- you have unexplained increased utility costs,
- there are more frequent needs for AC repair,
- Your system is no longer cooling your house evenly,
- your air conditioner is more than ten years old.
These are common signs that you need a new AC installation. And if you do not do it early, you may end up with broken systems.
Also, an excellent time to go for a new AC system is when you need to upgrade to a more efficient system. You can upgrade your single stage system to a two stage or a variable speed ac system. This is a sure way to considerably lower your electricity bills.
How Much Do The Variable Speed Air Conditioners Cost?
A variable speed unit costs between $4000 and $8000 for a new unit(1). This price varies depending on the SEER rating, the brand, blower type and even your location.
The installation of the variable unit typically costs $2000 to $4000. This often depends on the installation complexity and your location.
Are variable Speed AC Worth The Cost?
In most cases, yes.
You may spend $3000 more to purchase and install a variable speed air conditioner. However, it uses at least 15% less energy than two stage air conditioners. You can save up to 15% on your AC electricity cost.
It may take you a year or two to finally balance up this. However, in an air conditioner’s 10-25 years, a variable air conditioner will save you thousands of dollars.
And, with the extra comfort and convenience that it gives, it is definitely worth the extra upfront cost.
When NOT to Buy A Variable Speed AC?
A variable speed air conditioner is the most effective cooling technology. However, sometimes, it does not make sense to buy it.
Here are instances when you would rather buy a two-stage air conditioner:
- If you are planning to move soon. It may take a year or two to break even. Therefore, it is not worth it if you are planning to move houses before you can recoup the higher upfront cost.
- You have uninsulated ductwork: If you have uninsulated metal ductwork, you do not want to deal with condensation buildup. Unfortunately, insulating ductwork is usually too expensive. In this case, go for a two stage unit to avoid mold problems and water damage.
- You live in a mild climate: If you use your air conditioning less, even in summer, you will likely not need a variable speed AC system.
- Your energy costs are low: if your energy costs are low, getting a recoup from the upfront cost may be difficult. If you also use windmill energy or solar panels, a two stage or single-stage AC unit will be ideal.
Two Stage and Variable Speed AC Unit Frequently Asked Questions
We answer some frequently asked questions about variable speed vs two stage AC units. These questions will help you understand better which cooling technology is ideal for you.
Is 2 stage AC the same as variable speed?
There is a difference between the two. A 2 speed AC unit runs on two speeds, high and low. For the variable speed; there are numerous different speeds between the lowest and highest setting.
Also, a variable speed air conditioner runs more continuously without frequent switching on and off but uses less energy. A 2 speed AC unit switches on and off throughout the day but uses more energy.
This consistency makes a variable speed a great commercial AC.
Is variable speed AC worth it?
In many situations, yes, it is 100% worth it. You may buy it expensively, but with the lower monthly bills, you will save so much. Also, with the comfort and convenience that comes with them, it is worth every penny.
Does a variable speed air conditioner run all the time?
They turn on and off less frequently. This makes them more energy efficient because an AC unit uses more energy to turn on.
How Much More Expensive is a Variable Speed Air Conditioner?
It would usually cost $2000- $8000 more to install a variable speed. The price will depend on the brand, model, efficiency rating, and installation costs.
Final Thoughts on Variable Speed vs Two Stage AC
It is our time to wind up the two stage vs. variable speed air conditioner debate. At this point, we are convinced that you know the critical points of the two and, most importantly, know what suits you best.
Still unsure of what is best for you? Feel free to contact us for free answers.
Contact us 24/7 for HVAC services!