Making sense of vacuum cleaner specifications

Understanding vacuum cleaners, in general, can be hard at times - it's difficult to know which will be best for you and your home, let alone what all the technical bits mean.

At Gtech, we like to keep things simple - we make great products that our customers love, and we pride ourselves on being an honest and trustworthy brand. That's why we thought we'd run through what's behind all of the specifications we use on our vacuums.

These features are found on both corded and cordless vacuums, so you should be able to figure out what's going on, regardless of what model you have...

Voltage - measured in volts (V)

Voltage is essentially the way we measure electricity that's being supplied from an electric source. The electricity itself is a means of energy transfer, such as kinetic (think wind turbines) or solar energy.

Plug sockets in the UK are powered by our mains grid, and electricity comes out at 240V, with 10V lost through the process, giving us 230V. It's supplied to us as 'AC', which stands for 'alternating current' - because the direction of flow is constantly switching - and it's infinite in supply as it comes from the mains. You'll see it written as a 'V' on rating labels and in product descriptions.

A battery is a portable storage unit of voltage that contains a finite supply. Batteries can be charged, which replenishes them and means you can reuse them as needed. In comparison to our mains power supply, batteries use 'DC' voltage - 'direct current' - which means that the flow only goes in one direction around a circuit.

Gtech Pro K9 cleaning stairs

Current - measured in amps (A)

Current is the flow of electricity through a circuit - whatever draws it is using the power, such as a hairdryer that's plugged into the mains. Again, AC flows in multiple directions - this is constantly changing and is a consistent, stable form of high voltage electricity that comes from mains power outlets. If you're plugging a corded vacuum into a socket at home, for example, it will be running off AC.

DC, as we mentioned earlier, is direct current and only flows in one direction. Generally, this is linked to lower voltage sources, such as batteries, and solar panel electric generation. DC that is used in batteries is produced by conversions of chemical reactions to electricity.

Electrical power - measured in watts (W)

When we talk about wattage, we're talking about electrical power. To calculate wattage, you multiply the voltage by the current - this lets you know how much 'power' is being delivered. Let's simplify things...

Imagine a plumbing system with a water tank and different sized pipes coming in and out of it. The tank is the battery and the water in the tank is the finite level of electricity. The pressure in the system is the voltage as the water flows from the tank; the rate at which it flows is the current. The resulting flow that's generated by the movement of the water is the power which then turns a motor. It all comes together as a system, with power being measured in this way as it would be in an electrical item.

If you're wondering what this all means when it comes to vacuums, it's important to note that electrical power isn't a good indicator of performance, despite many people thinking it must be. We hear the word 'power' and assume that it links to how good a product is - how well it can clean our floors, for example. In fact, we should be looking at how the power is used to complete the primary task (vacuuming) and how efficiently it can complete it.

Charging battery pack for the Gtech Multi handheld vacuum

A product's power levels may be high but that doesn't mean that its performance will be. The wattage can actually be used inefficiently, like when motors overheat - this is a use of power but it's not a beneficial one. The wattage remains high but it's not being used in a good way for its primary function, so it doesn't really equate to anything in terms of performance.

Cordless products strive to be more efficient so that as much of the finite power available is delivered to cleaning as possible. That means that wattage isn't as important a factor as a lot of people think and that the way it's being used is what really matters. So, opt for a machine with a high wattage, sure, but make sure you find out how that's being used in terms of efficiency and consider other factors such as airflow, too.

Battery runtime - measured in watt-hours (Wh)

One thing to consider on battery-powered products is the watt-hours or watts per hour (Wh) of the product's battery pack. This is a good indicator of the amount of time your product will run for. This also depends on the amount of power your product uses and on the specification of the battery.

Going back to the plumbing system, the watt-hours would describe how big your tank of water is. If you have a large output pipe you would expect the tank to drain faster than if you had a smaller pipe.

A vacuum with an efficient running current and a large watt-hour battery will last a long time between charges. It is important to consider how long you want your product to run between charges when looking for your next vacuum - this is done by assessing the size and type of area you are cleaning and how much cleaning is needed.

Airflow - measured in volume per time, e.g. litre/second

Airflow is much more important than most people think, which is why we'll be going into more detail on it later. For now, we'll just explain what it actually is.

Essentially, airflow refers to how much air is moved in a given time across a surface. In simple terms, it's the speed of the air travelling through the airways of a product, in this case, a vacuum cleaner. This measurement takes into account the suction generated by the motor (see below for more info on suction) and the resistance of airflow due to filters or convoluted air paths that are long, winding or complex.

Airflow is probably the most important thing to look at when establishing the cleaning ability of a vacuum. Look at it this way - a vacuum cleaner that's blocked may technically be demonstrating a high level of suction by lifting whatever it is that's blocked it but, because it's blocked, the airflow is massively reduced and nothing more is actually picked up. Suction power is important in some ways, but airflow is definitely the first thing you should be looking at when considering buying a new vacuum cleaner.

Woman cleaning kitchen surface with Gtech Multi vacuum cleaner

Suction power - air watts

As mentioned above, a lot of people think that the most important thing about a vacuum cleaner is its suction power. Which makes sense, given that we all want a cleaner that picks up the dirt from around our home.

Technically speaking, suction power is calculated using airflow and vacuum pressure. It was originally devised as a means of converting electrical power to output power - essentially, how well a vacuum can pick up dirt. As a calculation, it's not really representative of how well vacuum cleaners can perform and can be pretty misleading.

Suction power measures how well a vacuum can lift heavy debris off the ground, which is relatively useful to know. However, it is airflow that moves that dirt through the airways and into the bin or bag, which is important when it comes to vacuuming. Airflow affects how the bin or bag fills up, which, in turn, affects the pickup performance and efficiency of your machine.

So, we've established that suction power picks up heavy items - so do rotating brush bars. Brush bars move across surfaces to agitate the dirt, and the airflow then lifts the dirt and transports it to the vacuum bin or bag. Ultimately, you want to be looking for good airflow combined with an agitator that works to physically bring the dirt into the vacuum rather than just focusing on suction power.

Our award-winning Gtech AirRam features a brush bar along with our unique AirLOC technology* which works to lift larger objects as well as finer dust and dirt.

In case you've always wondered what 'AirLOC' stands for, it looks at the airflow as well as the vacuum's abilities in terms of 'Large Object Collection'. Rather than just focusing on the suction power of our vacuums, we work to make sure other elements are also efficient and deliver the level of performance that people have come to expect from Gtech.

Cleaning width

This one's pretty self-explanatory, and quite a nice break after all the technical jargon. Cleaning width literally refers to the width of the cleaning head or attachment being used - simple. The wider the cleaning head, the more area that can be cleaned in a single pass.

That said, wider heads are obviously more restricted by where they'll actually fit when it comes to vacuuming. A huge cleaning head might mean fewer passes on a piece of carpet as you cover more space per sweep, but it poses a huge problem when you try to clean between chair legs.

The cleaning head on our AirRam is 295mm - we've designed it for busy homes where vacuuming needs to be a speedy job, with as few passes as possible delivering a great clean. We know that a lot of people struggle to fit cleaning into their busy schedules, so the AirRam was built to clean in between furniture and to move easily around any obstacles with its low profile, reclining handle, making it ideal for reaching underneath beds and sofas.

Weight

A heavy product (such as a typical mains-powered vacuum cleaner) is cumbersome and difficult to lift, especially if you're carrying it up and down stairs. In general, mains products have large AC motors that are pretty heavy, along with long cables that contribute significantly to the product's overall weight.

When you're using a corded vacuum on the floor, its wheels bear a lot of the unit's weight and the cable is being trailed, so you don't have to carry the weight of it. With cordless products, the majority of the vacuum's weight is in the battery pack itself. The batteries used in cordless vacuums tend to weigh much less than mains cables do, meaning the weight you actually carry is intrinsically lower.

The most relevant aspect of weight is the weight you feel in your hand while vacuuming. You can have two products of equal weight, but if one's weight is predominately in the floor head (and being supported by the wheels and floor) and the other's weight is in the handheld unit, it'll feel as though the handheld is heavier. That's because that's the weight that you're actually experiencing, so it's worth considering the style of vacuum you think will fit into your lifestyle, and home, best.

Filtration

So, we know about how airflow works. But what is filtration and why is it so important? As the air moves through the vacuum, it's laden with dirt and debris. Filtration is basically cleaning this air with the sole purpose of collecting it in a chamber whilst separating it from the airflow. Like sifting icing sugar through a sieve, you want to filter it out so that the finer particles fall to the bottom and make more room for the (soon to be compressed) larger clumps of sugar.

Filtration can be conducted via a filter, unsurprisingly, that traps dirt but allows air to pass, or by means of cyclonic separation. It might sound very scientific, but cyclonic separation is basically spinning the dirt around and waiting for the heavier bits to exceed the hold of the airflow so that they break away and drop down.

To measure how effective filtration is, we look at the size of particles that a filter can trap without becoming blocked and therefore restricting airflow, rendering the cleaner ineffective. Filtration is much more important than it sounds as it affects the overall performance of a vacuum cleaner.

So, there we have it - a brief guide to the technical side of vacuum cleaners. Hopefully, you've learned something new and have a better understanding of how your vacuum works. There's so much more to a great product that just suction power, so don't be afraid to delve a bit deeper and do your own research when it comes to choosing your next vacuum cleaner...

*AirLOC system is patent-pending - W02017/144922.