Scroll compressors are the modern solution when it comes to the world of HVAC. As you’re going to learn, they have a ton of useful traits. We’ll take a deep look into what they are, how they work, and why you should get one. Then we’ll look at a few big brands in the space, then a few products that might be the perfect selection for you.
What is a Scroll Compressor?
Scroll compressors are also called spiral compressors, scroll vacuum pump, or scroll pump. They are a type of compressor that has great use in industrial, manufacturing, and home use. They are becoming a good alternative to the previous industry standard compressors for HVAC applications.
Scroll compressors are just another type of air compressor. It pressurizes, heats, and pumps air from one place to another. The big difference is the motion that the scroll compressor uses.
This novel motion lends itself to a lot of advantages over the previous industry standards, the reciprocating and rotary compressors. Let’s learn more about how they work, how to use them, some advantages of this compressor, top brands in the space, and how they benefit over the previous industry standard compressors.
How a Scroll Compressor Works
Scroll compressors are a mighty little invention. If you can imagine two concentric spirals whose spirals are going opposite directions, you’re off to a good start. These spirals are called scrolls, hence the name. There’s a small off-center shaft with a keyway in the middle of the assembly.
The shaft will orbit quickly, making one of the scrolls also quickly orbit in a circle. While one scroll is quickly moving, the other scroll is staying stationary. Due to the geometry of the two scrolls, there is a passageway, or vane, that exists from the center to the outside – think of one of those maze games that appear on restaurants’ kid menus.
Now, when the one scroll orbits in a small circle, it is narrowing the passageway in a circular motion from the outermost point to the center. The scroll is orbiting in a counterclockwise direction. This, of course, results in compression.
Why Should you Get a Scroll Compressor?
The question is simple. Why is the scroll compressor becoming the new norm in industrial and commercial applications? There are a ton of advantages of using a scroll compressor.
Reliability and Life
Scroll compressors have a lot of advantages over other compressors. For one, they have much fewer moving parts. As you probably know, the less moving parts you have, the less maintenance you have to do. This also means there are fewer things that could go wrong. This makes for a more reliable and longer-lasting compressor.
Again playing into the fact that the compressor has a pretty simple motion, the compressor has less torque variation. This translates to a much smoother operation and less noise.
Two-stage and variable-capacity scroll compressors are known for their ability to control humidity well. They can hold temperatures in a home well and match the exact need of the house. This results in better control over humidity.
Due to the ability to modulate speeds of the scroll compressor, there is a big energy saving for the homeowner.
Due to the simple motion of the compressor, it takes up less space. This is important because it will minimize the overall size of the refrigerator or AC unit it is going into.
Of course, when you mention size and efficiency, that usually translates into the weight of the unit. Scroll compressors are a lot lighter than other compressors in the market. Often, they are up to 50% of the total weight.
The scroll compressor has fewer moving parts, better torque variation, and is a more efficient compressor. All of this plays into its noise level. Couple that with the fact that the motion is oscillatory and doesn’t involve any pistons or loud valves. The result is a very quiet compressor. You’ll notice the immediate difference in the scroll compressor’s noise level compared to other compressors. It sustains a low hum while other compressors you can hear constant vibrations and pistons firing.
Who Makes the Best Scroll Compressor
It’s not an easy answer, there are so many brands of scroll compressors you can buy. There’s Atlas Copco, Quincy, and Powerex on the top end of power. For lighter duty, you will find top brands like Copeland, Eastwood, Danfoss, and Trane. To pick just one is not an easy job. Let’s learn a little about each brand
Scroll Air Compressor Brands
Atlas Copco opened their doors in 1907 and delivered the first-ever mobile air compressor. It’s a brand that offers an industrial air compressor that is made with quality in mind. They deliver top air while reducing operating cost
Quincy has a very long history of success. Founded in 1920, they continued to lead the pack when it comes to air technology. It’s another brand that sells scroll compressors in the industrial-application side. Their commercial-grade scroll compressors have massive CFM potential and deliver the air quietly.
The last brand in the industrial category is Powerex. Their tagline is “the leader in pure air technology”, and their scroll compressor is no exception to this ideology. Founded in 1988, their sole focus has always been the engineering side of things. This results in more innovation and higher quality than its competitors.
First up on the list of lighter-duty scroll compressors is Copeland. Its roots go back to 1937 when it started making compressors for the refrigeration industry. They are arguably the best name in air technology, and that’s largely due to their obsession with the future of the industry. They roll out newer generations of technology, and that applies to their scroll compressor operations too.
Eastwood is another brand known for its smaller scroll compressors. They were founded in 1978 to serve the auto restoration and hobbyist market. Their products are still aimed towards garages, shops, and hobbyists. They make small scroll compressors that are very powerful and more efficient while minimizing noise.
Danfoss’s history traces back to 1971, starting with the production of compressors. 11 million units later, and here we are. They are one of the top names when it comes to light-duty scroll compressors. They sell units for commercial refrigeration. Danfoss focuses on minimizing operation costs and maximizing the efficiency of their scroll compressors.
The final name on this list is Trane, and it’s a big name. Since 1973 they’ve been consistently delivering heating and cooling products for the industrial world.
Their compressors are lighter duty and boast exclusive energy-saving solutions. Since they first opened their doors, their focus has been on R&D, supplying the newest technology, and improving the previous designs.
Best Light Duty Scroll Compressors
Best Industrial Scroll Air compressors
Let’s take a look at two of the best industrial scroll air compressors on the market.
The first industrial scroll compressor on this list is one of Atlas Copco’s. This unit touts a massive 22 HP electric motor. It cranks out up to 141 PSI and can hold 49.8CFM at 141 PSI. It comes in just over 1300 pounds.
This is an incredible option when it comes to an industrial setting. It has huge power, a big capacity, and somehow delivers the pressure at just 64 dBA. This means you get everything you need in a scroll compressor at a volume comparable to normal conversation!
Next is Powerex’s scroll compressor, the Octoplex. It features a generous 40 HP motor, and can deliver a max of 145 PSI. It can put out 100 CFM at 100 PSI, which is a huge amount of air. It weighs in at one ton. Of course, this product can give you all of the air you need and more. It is rated to operate at 60 dBA which is thanks to their engineered sound enclosure. Overall it’s the perfect choice for most industrial applications.
Are Scroll Compressors the Better Option?
It depends on the application, of course. We are seeing the market start to shift towards using scroll compressors for a few reasons. They’re smaller, less likely to fail, and much quieter than what used to be the standard.
They also offer much better energy savings and humidity control over the other compressors you could pick. Finally, they typically have a longer life and better reliability than other compressors.
Causes of Scroll Compressor Failure
There are a lot of different reasons for a compressor in your heat pump or air conditioner to fail. The refrigerant lines could be blocked, the refrigerant charge could be low, cracks or holes in the lines, or an incorrectly sized suction line. All of these will also lead a scroll compressor to fail.
There is one method of failure that is specific to just the scroll compressor, though. A reciprocating compressor can operate in either direction and still work, but a scroll compressor has to move in one specific direction. If there is a quick power interruption, your scroll compressor might actually start running in the wrong direction. This will lead to overheating and tripping the overload protector, making your scroll compressor fail.
Scroll Compressor vs. Reciprocating
Reciprocating compressors were the old norm. They use a piston and cylinder to compress and pump refrigerant. Comparing the two yields a pretty polarizing result.
The scroll compressor is a more efficient, quieter, and smoother compressor. It also touts better energy efficiency, higher reliability, and fewer mechanical failures over its lifespan. Scroll compressors also cost less money to manufacture so replacing it sometimes costs less than repairing it.
Beyond these characteristics, the scroll compressor also has a greater cooling capacity due to its streamlined and powerful design. It can heat or cool air faster and does all of this at a lower sticker price than a reciprocating compressor. Reciprocating compressors are a lot louder than scroll compressors, so you would want to avoid using these in AC units in your window or main areas of your home.
Scroll Compressor vs Rotary Compressor
Scroll compressors are much better at cooling and are more energy-efficient than rotary compressors. Rotary compressors typically have more power than scroll compressors, which means they can cool a higher capacity of air.
Unfortunately due to the complicated geometry of the scroll, scroll compressors are really hard to repair. The units will typically have to be replaced instead. The rotary compressor is a lot easier to repair but does have a more complex design. This means the rotary unit is more likely to breakdown but is easier to repair.
The rotary compressor is more likely to breakdown, but it is worlds easier to service and repair than the scroll. The rotary compressor is actually the most powerful compressor in this space. This also means it has the highest capacity for cold air. These are two areas that the rotary is preferred over the scroll. Additionally, rotary compressors don’t get nearly as hot – which might not be a problem as long as the coils are clean. Finally, the rotary compressor has a lower sticker price than its scroll counterpart.
Scroll Compressors Used in HVAC
In the HVAC world, you’ll most typically see a scroll compressor used in an air conditioner or a heat pump. It works just like any other refrigerant compressor. They are becoming increasingly popular over the traditional reciprocating compressor. The big reason for this is because of their increased reliability and efficiency.
In the case of an HVAC application, the scroll compressor will have a refrigerant that it’s compressing and pumping. The refrigerant will start its journey in the outside of the scroll and work its way in and towards the center along the vane as the scroll orbits. This will raise its pressure and temperature before it ultimately gets to the center. In this case, the center is a center port that will feed to the condenser.
Single-Stage Scroll Compressor
This is the simplest and least expensive type of scroll compressor. Single-stage units only have one fixed speed they can run at. They have all of the benefits of a scroll compressor they are just less expensive.
Two-Stage Scroll Compressor
This type of scroll compressor runs at two different speeds. It can better match the heating or cooling need for the home. Since they can run at a slower speed, it actually removes the excess humidity in the air and saves energy. Two-stage scroll compressors are usually the more energy-efficient version over the single-stage.
Variable-Capacity Scroll Compressor
As the name suggests, this type of scroll compressor can change its capacity in small increments across a wide range of operations. This is the most expensive model, but due to its ability to dial in on its capacity, it will yield great savings in the energy bill.