Exhaust Fan Power Consumption

posted on Feb 21, 2024

It is always better to have an exhaust fan in your kitchen and bathroom to push hot air and keep the room cooler. In bathroom, exhaust fans can keep the surface dry and minimize the possibility of mould and mildew.

Although exhaust fan wattage differs from brand to brand, but on an average, it consumes around 30-40 Watt of power. It is recommended to switch ‘ON’ your exhaust fan for 20 min after bath. So, overall if you switch it ‘ON’ for 6 hours it will cost you around RS. 35-65 per month.

Checking the wattage of exhaust fans

Your ceiling fan wattage decides the energy it will consume. Almost all the fans are marked with Watt they consume. You must check your fan wattage especially if the electricity rates are on a higher side in your area.

You must check the label of the exhaust fan you have bought. Note the counts of amp which may range from 0.25-0.5 for an average exhaust fan. A larger motor will have more count of amps.

Usually an exhaust fan consumes around 50-55 watts.

Calculating the power consumption of an exhaust fan

Power consumption is directly connected to your electricity bills. Hence while buying any exhaust fans the first thing you must consider is the amount of wattage your appliance will consume.

If you know the power of your exhaust fan in Watts (W), you must divide it by 1000 to convert it into kWh. For instance, if your exhaust fan is 70 W, then its power consumption will be 0.07 kW.

Today, BLDC motor exhaust fans have also gained popularity because of their energy efficiency. These fans usually consume around 28-40 watts of power. Hence, exhaust fans with a BLDC motor have greater capability to save your electricity bills.

Energy consumed by exhaust fans in a day

Usually, an exhaust fan consumes around 0.04 kWh of energy per hour. So, depending on your usage in a day, you can calculate the energy consumption of exhaust fans. Let’s take a look at the energy consumption table of exhaust fan

Consumption	Total (Wh)	kWh
Hourly	70	0.07
Day	840	0.84
Month	25200	25.2
Yearly	302400	302.4

The above table shows that your exhaust fan runs 12 hours a day.

Hence, it is clear that your yearly exhaust fan wattage will be around 302.4kWh, which is 5% of your electricity bill.

Cost to run exhaust fan for 24 hours.

It is a simple calculation to know the annual cost of your exhaust fan if it runs the whole day. The first step is to know your exhaust fan wattage. You can determine that from the label present on the fan itself. Once you know the wattage, you can divide it by 1000 to convert it into KW. So, if your exhaust fan is 50 50-watts, then it will be 0.005 kWh.

Now follow the below-mentioned steps:

Now, you need to multiply the KW figure by the average electricity price of your area. In India, the average price is around Rs. 6.4.
Multiplying 0.005kWh with 6.4 will give you Rs. 0.032-kWh. And in a year, there are 8760 hours, so your annual cost will reach around RS. 280.32
Keep in mind that this figure indicates continuous running of the exhaust fan 24/7, which is practically impossible. To get the practical number, you must calculate the number of hours per day your exhaust fan runs and multiply it by 365 days.

Power consumption of different types of fans

Power consumption usually depends on the type of exhaust fan you are using and the duration of usage. Below-mentioned is the power consumption of different types of exhaust fans which you can consider while buying.

Exhaust fan type	Average wattage	Average units per day	Average cost per day	Average hours of usage
Ceiling mounted	50-80 watts	2-4 units	$0.10-$0.20	1-2 hours/day
Wall Mounted	40-60 watts	1-2 units	$0.08-$0.16	1-2 hours/day
Window Mounted	30-50 watts	1-2 units	$0.06-$0.12	1-2 hours/day
Inline	60-100 watts	3-5 units	$0.12-$0.25	1-3 hours/day
Attic	100-200 watts	5-10 units	$0.20-$0.40	1-5 hours/day

You can also look for BLDC exhaust fans to save more energy.

How to save energy by using an exhaust fan

Ideally, you must keep your exhaust fan switch ‘ON’ for 20 minutes after a bath. During this time, your fan will be able to exhaust moisture. Exceeding this time limit will be power wastage.
You might forget to switch ‘OFF’ the exhaust fan after 20 minutes. Hence, to avoid such conditions, you can set the timer mode in the fan. It will automatically switch if ‘OFF’ after a certain duration.
You must replace the exhaust fan capacitor after every 6 months. A weaker capacitor may reduce the fan speed.
Your exhaust fan should contain a smaller size mesh, as the longer mesh will block the outlet air, and it will become difficult for the fan to exhaust the bathroom air.
You can go with BLDC motors, as they are more energy-efficient than normal exhaust fans.

Conclusion

Exhaust fans play a pivotal role in maintaining indoor air quality, but these fans can cost a lot on your electricity bills if not used properly. You must be aware of your exhaust fan wattage and the things you can do to reduce your energy usage. You must buy the right size exhaust fan for your bathroom or kitchen and clean it regularly to maintain its optimal performance.

Also, look for BLDC motor exhaust fans, as they are more energy efficient. These fans usually come with remote control and timer mode features.

Frequently Asked Questions

How much power does an exhaust fan typically consume?

On average, an exhaust fan consumes around 30-40 watts of power. If you use it for around 6 hours a day, then it will cost around Rs. 35-65 a month.

Are there energy-efficient exhaust fan options available?

Yes, exhaust fans with BLDC motors are considered the most energy-efficient fans. The BLDC exhaust fan wattage is typically around 16 watts. Also, BLDC exhaust fans come with a remote control, thus making them more convenient for the users.

Does the size of an exhaust fan affect its power consumption?

Usually, fans with larger sweep sizes will consume more energy. The common size of an exhaust fan is around 150-300 mm.

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