How Much Electricity Does An Air Purifier Use?


If you are looking to improve the air quality at home, spending a few bucks on an air purifier is the way to go.

Though it sounds like a wonderful investment, a question on everyone’s mind is “How much electricity would an air purifier use?” Compared to many appliances at home, an air purifier is very energy efficient. If it were to run 24/7, it would typically result in an additional cost of about $50-$100 per year.

But this is an average statistic because many more factors come into play when answering this question. A good understanding of these elements will let you bring down the annual electricity cost of an air purifier to about $16 or even less.


Understanding Electricity Usage of an Air Purifier

To understand the power consumption of an air purifier, we need to touch on a few basic electrical concepts.

Electrical appliances need energy to work, and an air purifier is no different. The amount of energy needed by a device to operate is measured in “Watts(W)” and 1000 watts equal to 1 Kilowatt(kW).

If you’ve handled electronics before, you might have already heard of ” the power/watt rating”. The watt rating of an electrical device is the amount of energy it or in our case, the air purifier needs to function. The product specification of an air purifier usually has its watt rating listed. If not, it’s just one google search away.

Different brands and models of air purifiers come with different watt ratings that may range from about 20w to 950w. However, a common household air purifier is 50w on average.

The product of a device’s watt rating and the time it spends in operation (watt rating x hours) is what’s commonly used to measure electricity consumption. The unit of measurement is Kilowatt-hour(kWh). It also acts as the base for calculating your electricity bill. For example, if a 50w air purifier operated for 12hours, its electrical consumption would be 600Wh or 0.6kWh on that day.


The True Costs of Running an Air Purifier

Now that you’ve got an idea about a few basic electrical concepts, let’s crunch some numbers to figure out the costs of having an air purifier. I know it sounds daunting, but bear with me and I promise you that by the end of this section you’ll learn to cut down your purifiers electricity cost to $16.

To tackle this task with ease, let’s come up with 2 scenarios.


Scenario 1

You have an air purifier with a watt rating of 50W and it runs all day long(24 hours). Assuming that your local electricity rate is 12 cents per kWh, the annual cost can be calculated as follows.

Daily electricity consumption = 0.05kW x 24h = 1.2kWh

Monthly electricity consumption = 1.2kWh x 30 = 36kWh

Annual electricity consumption = 36kWh x 12 = 432kWh

So, your annual cost would be = 432kWh x $0.12 per kWh = $51.84


Scenario 2

Now, let’s see how you can cut down costs to $16. Assume that the local electricity rate and the time the air purifier runs each day remains the same. But the air purifier you now use has a watt rating of 15W.

Daily electricity consumption = 0.015kWh x 24h = 0.36kWh

Monthly electricity consumption = 0.36kWh x 30 = 10.8kWh

Annual electricity consumption = 10.8kWh x 12 = 129.6kWh

The annual cost would then be = 129.6kWh x $0.12 per kWh = $15.5

Keep in mind that you can do the above calculations on any electrical device, and not just on air purifiers.


Other Elements that Affect an Air Purifiers Electricity Usage

It’s clear that watt ratings and running times contribute to a purifier’s electricity usage. But are they the only factors you need to worry about?

No, even though they seem like direct factors that influence electricity consumption, there are a few indirect factors you need to look out for.


The Coverage Area

Every air purifier has an area that it can effectively cover. The more coverage an air purifier provides, the greater its watt rating is going to be.

The coverage area can be typically found in the air purifiers product specification. At times manufacturers include tags like “Large room purifier” and “Small room purifier” along with the model name to help you get a rough idea about the coverage area.


CADR and Energy Star Label

CADR stands for “Clean Air Delivery Rate”. Simply put, it is the rate at which clean air is injected into a room. Higher CADR result in better air quality and faster rates of filtering. But this also leads to larger amounts of energy consumption.

The Energy Star performance of an air purifier takes the ratio of CADR and watts consumed into account. So, if the product has a good Energy Star rating, it means that it is energy efficient.


The Operating Environment

The environment a purifier operates in affects the amount of work it has to do. If it’s a highly contaminated environment, the air purifier will have to do more work than it does in a standard surrounding. More work needs more energy leading to greater electricity usage.


Air Purifier Technology and Settings

Not all purifiers are made equal. Different models employ various technologies to purify air. The following are five common technologies used in everyday air purifiers.

High-Efficiency Particulate Air (HEPA) filters – Purifiers that use this technology have fans to suck in air. The air that’s sucked in then passes through a fibre-like material which traps the pollutants. These types of purifiers usually have different settings to control the fan speed. Running the fan on high speeds usually consumes more electricity than when it’s run on lower speeds.

Activated carbon filters – Air purifiers that use activated carbon filters function very similar to HEPA filter purifiers. They suck in the air using a fan but pass it through carbon that has been processed and not a fibre like material. The running speed of the fan in these purifiers also contribute a lot to the overall energy consumption.

Ionizer – These air purifiers produce negative ions that get attracted to positively charged air particles such as dust. Once they combine, the particles become too heavy to stay airborne and falls onto the ground. These fallen particles should then be vacuumed or cleaned manually. This makes Ionizers less effective than other types of air purifiers.

Ultra Violet (UV) technology – This method uses UV light to eliminate bacteria, viruses, and other types of germs. However, UV light doesn’t take care of pollutants such as dust and pollen. So, most UV light air purifiers also come with a filter system (such as HEPA filters) installed. The UV light and the fan (if installed) will consume most of the electricity.

Mixed Technology – Many air purifiers produced nowadays combine two or three of the technologies listed above. This leads to varying levels of electricity usage. Hence, as a general rule of thumb, it’s best to keep in mind that the more work the air purifier does, the more electricity it will consume.

You might have already noticed that the amount of electricity an air purifier uses can be controlled to a certain extent. With a solid understanding of both the direct factors and indirect factors that affect energy consumption, there’s no doubt that you will be able to select the best purifier your home needs.


Related Questions

Are air purifiers worth it?
The answer to this question depends on a few factors. If you live in a city with high levels of air pollution, investing in an air purifier is totally worth it. However, if u live in a less polluted area, it need not be a priority.

You already know that you have a certain amount of control over its running costs. So, if you have some money to spare and you feel like the air you breathe at home isn’t the best, go for it.


How much does it cost to maintain an air purifier?
The maintenance cost depends on the type of air purifier you own. If it’s a filter-based air purifier, you would need to change its filter at least every 2 to 3 months. This mostly depends on the environmental conditions the purifier functions in.

Nowadays certain high-end air purifiers only need filter replacements every 6 months. The price of a filter can vary depending on its brand and type. On average, a filter costs between $25 and $250. Other types of air purifiers also have different replacement costs for parts, but it eventually boils down to the model.


How long should an air purifier operate?
An air purifier needs to operate throughout the day (24 hours) to get the best results out of it. This is because airborne pollutants will always tend to seep in unless the room is literally airtight.

The CADR value and the coverage area help in determining how long a purifier would take to clean a room. Typically, it would take about 45 minutes to 3 hours, give or take. You might also want to consider the different seasons. For example, there’s more pollen produced in the summer, so an air purifier might have to operate for longer periods during this time.

Even so, the running time of an air purifier depends on the purpose it’s used for and is entirely up to you.