#### Short answer

#### Long answer

In the U.S. electricity cost for residential varies from states to states. Based on May 2019 EIA report, Washington cost the least at **9.81 Cents** per Kilowatt-hour while Hawaii cost the most at **33.43 Cents** per Kilowatt-hour. That's a huge **23.62 Cents** gap in between. The elecitricity cost on average is at **13.32 Cents**.

## How to Calculate an Air Purifier Energy Cost

It’s easy as 1 2 3. First you calculate the total wattage consumption per day e.g. 70 watts X 12 hours = 840 watts. Then you convert watts to electricity measurement e.g. 840 watts/ 1000 = 0.840 kilowatts. Continue calculating the monthly usage by multiplying accordingly. E.g. 0.840 kWh x 30 = 25.2 kWh per month. Finally, use your local electricity rates, multiply the figures, and voilà, there is your answer. E.g. 25.2 kWh x 0.15 = $3.78 per month. Using that as a baseline, you should be paying between $3-8 dollars monthly with 12 hours of daily operation. Hardly any dent on your electricity bill.

To recap, here is the formula we used for the above example.

**W x 12 (hours) / 1000 (kilowatts) x 30 (days) x 0.15 (rates) = Cost per month**

For yearly energy cost just multiple the months by 12.

**Cost per month x 12 = Cost per year**

## How Much Electricity Does an Air Purifier Use?

Depending on the airflow speed, Most HEPA air purifiers consume around 50-100 watts per hour. With 12 hours of daily operation, the electricity will be around $3-5 a month or $36-60 annually. With 24 hours operation, you just need to multiply the numbers by 2 so the cost would be at $6-10 a month or $72-120 annually.

The above and below figures are calculated with the baseline rate at $0.15 per kilowatt-hour.

Winix 5500-2 | Coway Mighty | Airmega 300 | Levoit LV-PUR131 | |||||
---|---|---|---|---|---|---|---|---|

12 Hours | 24 Hours | 12 Hours | 24 Hours | 12 Hours | 24 Hours | 12 Hours | 24 Hours | |

Power Consumption (Max) | 90 watts | 78 watts | 57 watts | 40 watts | ||||

Daily Cost | $0.16 | $0.32 | $0.14 | $0.28 | $0.10 | $0.20 | $0.07 | $0.14 |

Monthy Cost | $4.80 | $9.60 | $4.20 | $8.40 | $3 | $6 | $2.10 | $4.20 |

Yearly Cost | $57.60 | $115.20 | $50.40 | $100.80 | $36 | $72 | $25.20 | $50.40 |

Energy Star rated |

## Does Air Purifier Use A Lot Of Electricity?

No, as its power consumption is on the lower end of household appliances. You can leave your air purifier on all night and it will have little impact on your electricity bill. Some air purifier energy consumption is around the same rate as a light bulb at LOW speed (keyword: LOW). To put things into perspective, a normal television uses 70 watts of electricity per hour. A refrigerator uses 200-300 watts and an air conditioner uses 600 watts. Washing machines are the biggest power hogger that uses 2000 watts of electricity.

## How to Choose An Energy Efficient Air Purifier

Look for models that are Energy-Star Rated is a good way to start. Then refer to the air purifier’s power usage in the specification. Features like Auto/ Sleep mode will help manage power consumption. Some models even have Eco-mode that will turn off the motor fan when not in use. Choose the right air purifier that would cover the exact room size. An air purifier that does not fulfill the coverage would take ages and higher speed to cover an entire room.

Another bonus tip is to keep your windows shut when the air purifier is in operation. This will block out external pollutants from coming in. Also, replace the filters when is worn out to maximize the filtration efficiency. Remember, a good air purifier does not need to operate at MAX speed all the time. The lesser the airflow, the lesser energy it uses.