You’ve started your research on regulators while trying to decide what to buy, and you keep coming across the same confusing terms — balanced or unbalanced. What do they mean?
What is the difference between a balanced and unbalanced scuba regulator?
Essentially, a balanced regulator will breathe the same no matter how deep you are or how much air is left in your scuba tank (the ease of breathing is not dependent on your tank pressure). An unbalanced regulator, however, may feel more difficult to breathe from as the pressure in the tank gets lower, or as a diver’s depth changes during the dive.
If you read the diaphragm vs piston regulators article, the first stage of a regulator always has a bias spring and a high pressure seat / poppet valve assembly that directs (and responds to) the intermediate pressure air movement.
In a balanced regulator, these gear pieces operate at the same force no matter what ambient pressure levels are.
In other words, the pressure coming from the tank and the ambient hydrostatic pressure from a diver’s depth do not affect the regulation of the intermediate pressure chamber in the first stage.
While the term “balanced regulator” usually refers to the first stage of a regulator, a second stage can also be balanced or unbalanced.
In any second stage, a diver’s inhalation opens a valve that is tensioned by a spring inside the second stage body (similarly to when the piston or diaphragm in a first stage moves to open a pathway between the high pressure and intermediate pressure chambers).
In a balanced second stage, there is an intermediate pressure stored on the backside of the valve to counteract the tension from the spring (without this intermediate pressure pocket, it would be more difficult for a diver to pull breath from the regulator).
This ensures the consistent ease of breathing from the second stage and the first stage (if both are balanced).
As a note, it is unlikely that a diver will be able to notice a significant difference in ease of breathing between a balanced or an unbalanced second stage as long as it is paired with the balanced first stage.
If the first stage is unbalanced, a balanced second stage may assist slightly in easier breath pulls.
With an unbalanced regulator, a diver may have to use more physical effort to pull a breath as tank pressure or ambient pressure decreases.
Essentially, the spring and high pressure seat system in the first stage of an unbalanced regulator responds (opens and closes to allow air through the first stage into the second stage) to tank pressure/ambient pressure instead of the controlled intermediate pressure flow of a balanced first stage.
This results in less consistent air flow to the second stage and therefore a more difficult feeling breath.
While this labored breath pull may seem daunting to some readers, rest assured that unbalanced regulators are completely safe and still provide the diver with ample air.
The novice diver may not even be able to tell a difference in the air flow, but as a diver becomes more in tune with their gear and explores new environments, the subtle difference in breathing ease between a balanced and unbalanced regulator could become a strong preference.
Which is Better?
As mentioned above, many divers would be unable to tell the difference in breathability, particularly if the regulator is only being used for recreational diving depths.
For deeper dives or more technical realms of diving, the physical effort it takes to pull a breath could become more important to a diver (whether the preference skews the direction of a diver needing an easier breath at all times, like in a strong current, or whether the diver likes to be able to feel it getting more difficult to breath as the tank pressure lowers to signify an approach toward low air in the tank).
Both regulator styles are 100% safe and effective, but inevitably each diver will have their own opinion over whether to choose a balanced regulator or an unbalanced one.
Why Aren’t All Regulators Balanced?
If a balanced regulator is easier to breathe from and the breathing ease remains consistent at all depths and tank pressures, why wouldn’t all regulators just be balanced? Why do manufacturers keep making both styles?
This mostly comes down to price.
The design of a balanced regulator is a bit more intricate and requires more complex servicing skills.
This added design complexity, although not majorly more intricate than the design in an unbalanced regulator, raises the price to both the manufacturer during the build and to the owner to upkeep the regulator.
Because of this, the sale price of a balanced regulator is consistently higher than the sale price of unbalanced regulators.
Therefore, unbalanced regulators remain popular for a diver’s first regulator purchase if the diver is on a budget, and just getting started with a few recreational dives per year.
A diver must weigh the pros and cons of each regulator type to decide whether price, longevity/durability, regulator needs based on the type of diving, and comfortability is most important to them.
To learn more about choosing the right regulator, head over to our How Much Does a Diving Regulator Cost article! And don’t forget to leave your comments below.
Well explained! Thank you. New scuba diver here; going through the SDI open water course now and trying to learn more in depth about the gear.
I have another question you might be able to answer if you wouldn’t mind emailing me back!
What is the difference between 15x and 72x regulators; such as with the Mares Loop. Thank you and keep writing!