2 Stage vs Variable Speed Air Conditioner – Which One Should You Choose?

Air conditioning units are highly effective at controlling the temperature of your property in the warmer months. When the temperatures increase, you need to stay cool indoors. Therefore, choosing the right air conditioner is essential – but what options are at your disposal?

When it comes to selecting your air conditioner of choice, you have two main systems to look at:

• Two-stage 
• Variable speed

Naturally, you might not even know that different types of air conditioning units existed. As such, how will you know which one of these is right for you? In this guide, we’ll help you understand everything you need to know about either option, including their key differences and benefits, helping you make a more informed decision when buying your next AC unit. 

 

What Are Two-Stage AC Systems?

A two-stage AC system is commonly referred to as a dual-stage system by many people in the industry. The key thing about this unit is that it operates at two different speeds. In other words, it has two different stages, hence the name. 

With a two-stage compressor, the AC refrigerant gets pumped throughout the system. This is exactly how it happens in a standard AC system, but the difference here is that there are two different stages of cooling. One stage runs the system at max capacity on the highest setting. This delivers the most amount of cooling throughout your property. Alternatively, the second stage sets the system to run at a much lower capacity. The exact percentage depends on the unit, but it is typically around 60% of the max capacity. 

Two-stage AC systems are seen as an evolution of the classic one-stage system. A one-stage AC unit is the most traditional and bog-standard option out there. They only have one stage, meaning they operate at one speed. You turn it on, and you turn it off. As you can see, the two-stage variant is a great improvement on this as you can choose to run it at a lower capacity if you need to. 

 

What Are Variable Speed AC Systems?

If a one-stage system has one speed and a two-stage has two, how many speed settings are there on a variable one? Well, the answer is that there are almost limitless settings the system can run on. The exact number of speed settings depends on the product, but the idea is that you can vary how powerful your AC unit is. Variable systems let you make small adjustments to run your system at a level that suits your needs. 

Think of it as a thermostat in your home, but for cooling purposes. In the winter, if you want to heat your home up, most thermostats let you select a temperature and make small adjustments. Imagine if you could only set your heating to be on or off, or at full capacity or 6- per cent! A variable AC system simply gives you more options, which leads to a whole host of benefits. 

 

Two-Stage System Benefits

What are the benefits of a two-stage system?

Well, there is one key benefit when compared to a one-stage system! With a two-stage operation, you get much more energy efficiency than you would from a one-stage product. A normal one-stage air conditioner will be on full-blast until your home reaches the desired temperature set on the thermostat. This requires a lot of energy, and the unit will blast itself back on if the temperature starts to increase – which it will likely do during the day. 

Looking at the two-stage variant, it can operate at full power when required, then be turned to lower power when you want. This means it uses less energy to cool down your home as it can run on a setting that’s around 60% of the max capacity. In theory, this means you can use around 40% less energy to cool your home. 

 

Variable System Benefits

However, the variable air conditioner is a far better option than both of the previous two we have mentioned. Going back to our description of how one-stage systems cool your home, how does this work with a variable unit?

Essentially, variable speed compressors work completely differently from this. Instead of being at 100% capacity, the system will run much lower. In most cases, this can be as low as 25% capacity. They will then blow a consistent stream of cold air throughout your home to maintain the desired temperature. To do this, they run almost continuously throughout the day until you turn the system off. 

While this might seem like more energy gets used, it actually leads to far less energy consumption. Interestingly, your air conditioner uses up most electricity when it is turning on, not when it is running. Therefore, with single or two-stage units, they are turning off and on many times throughout the day. A variable system turns on once, and that’s it. Then, it runs at a lower capacity, demanding even less electricity than the other units. As a consequence, less energy gets used, making this the most efficient type of air conditioner you can find. 

Furthermore, variable air conditioners can also dehumidify your home far better than a two-stage or one-stage system. This is all down to the continuous pouring of cold air from the compressor. It helps to maintain a cooler temperature at all times, which keeps the humidity down. A huge issue with other AC systems is that they cool the house then turn off. When they turn off, your home starts to feel more humid and hot. As a result, it becomes more uncomfortable, and you struggle to sleep at the end of the day. The constant nature of a variable air conditioner eliminates this and makes your home more enjoyable to be in. 

Finally, the fact that these systems run at a lower capacity means that they are much quieter than other options. Two-stage systems will be quieter than one-stage ones when operating on the lower setting, but variable ones barely make noise throughout the whole day. 

 

Two-Stage & Variable Speed Air Conditioners Impact On Air Quality

By now, you should have a pretty good idea about how both of these systems work and how they are beneficial. In essence, a two-stage unit is an improvement on a one-stage, offering greater energy efficiency – while also improving the humidity levels as it does run slightly more frequently than the one stage. 

Still, the variable air conditioner is a level up yet again. It takes energy efficiency to new levels and offers even better dehumidifying. Nevertheless, we can look at one area where both of these systems triumph over one-stage air conditioners and improve your home; air quality. 

Both the two-stage and variable options will help to purify the air in your home. This is all down to their dehumidifying benefits, which enable them to prevent things like mold growth and dust mites. The result of this is cleaner air that’s free from certain allergens and pollutants. 

Of course, variable units are still more effective at doing this, seeing as they are better dehumidifiers. In turn, they can also be very good at filtering your air and cycling it through the ducts. As a result, you have cleaner air entering your indoor space. 

 

The Cost of A Two-Stage AC Unit vs. A Variable One

Whenever you’re looking to buy anything, you need to consider how much your options will cost. One-stage AC units are the cheapest, largely because they’re the least technologically advanced and the least efficient. 

With that in mind, a two-stage air conditioner is significantly cheaper than a variable one. As expected, the variable unit will always be more expensive because it has more technology inside of it. Moreover, you should take into account the energy bill savings you could make with the most efficient option in your home. 

However, if we are going to directly compare the installation costs, you have to give two-stage units the win here; they are considerably cheaper. 

 

Conclusion: Which Is Better?

After reading through this guide, you should have a deeper level of understanding about both of these air conditioning systems. To recap, here are the main points:

• Two-stage air conditioners have two settings: one at 100% capacity, and the other running at around 60% capacity
• Variable air conditioners run at much slower speeds that can be as low as 25% capacity
• Variable air conditioners run for longer but use up less energy
• Both variable and two-stage air conditioners help to dehumidify and purify the air in your home
• Two-stage air conditioners are the cheaper option

Overall, which option would you say is the best?

Generally, variable air conditioners are a smarter choice as they offer the same benefits as a two-stage system – but taken to new levels. They are also quieter, better air filterers, and tend to last longer. The only reason you might opt for a two-stage over a variable is if you don’t have the budget to get the high-end option. 

Either way, upgrading your AC system is a great way to improve energy efficiency and create a more comfortable living space during the warmer months of the year. 

You might want to read “How to Reduce Your Heating Cost By Using Central Heat Instead of Space Heaters”.