A 24-hour ventilation system is common in many newer rental properties. Some people turn it off because they feel the electricity cost is wasteful, but the actual cost is lower than expected, while the risks of stopping it are greater. This article explains the types of ventilation fans, typical electricity costs, and practical ways to save energy.
How much does a ventilation fan actually cost to run?
Ventilation fans are among the lower-power household appliances, and even when left on 24 hours a day, the monthly electricity cost is usually only a few dozen to a few hundred yen.Typical costs by location (based on 31 yen per kWh) are as follows.
- Toilet: about 42 to 67 yen/month (power consumption of around 3W)
- Bathroom: about 290 to 446 yen/month (power consumption of around 13 to 20W)
- Kitchen: about 446 to 670 yen/month (power consumption of around 30W). Models with a continuous ventilation mode are about 112 yen/month
Why is it better to leave a ventilation fan running?
The benefits are significant relative to the low electricity cost, so leaving a ventilation fan running is generally recommended.
- Condensation prevention: Continuously removes indoor moisture and helps prevent condensation that can lead to mold
- Mold and mite prevention: Helps avoid higher move-out costs and health issues such as sick house syndrome and allergies by preventing mold growth
- Odor control: Constantly expels trapped household odors and helps prevent them from settling into curtains and sofas
- Air exchange: In airtight homes, opening windows alone is often not enough, so a ventilation fan becomes the main way to circulate air
What is the difference between ventilation fan types and a 24-hour ventilation system?
A standard ventilation fan is intended for "short-term ventilation when needed." By contrast, a 24-hour ventilation system is "ventilation that runs continuously to address sick house concerns and prevent condensation."Homes built since 2003 are required to have a 24-hour ventilation system installed, so it should not be turned off.
4 tips to reduce ventilation fan electricity costs
- Run it with windows and doors closed: Improves ventilation efficiency in an enclosed space and reduces unnecessary power consumption
- Clean it regularly: Dirty filters reduce ventilation efficiency and can raise electricity costs, so using filters can make cleaning easier
- Use low-power mode: When using an air conditioner, switching the fan to low-power mode can save electricity without unnecessarily reducing AC efficiency
- Replace an aging ventilation fan: Fans that have been in use for more than 15 years become less efficient and noisier. Replacement may also reduce power consumption
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Frequently Asked Questions (FAQ)
Q. Are there any legal issues with turning off a 24-hour ventilation system?
A. Installation is required under the Building Standards Act, and it is not recommended for occupants to stop it. Because the purpose is to expel chemical substances that can cause sick house syndrome, turning it off carries health risks.
Q. Is it okay to use a ventilation fan and an air conditioner at the same time?
A. Yes, but the ventilation fan can expel cooled or heated air from the air conditioner, which reduces efficiency. When using an air conditioner, you can minimize the impact by running the fan on low-power mode or adjusting the AC temperature setting.
Q. How often should a ventilation fan be cleaned?
A. For toilet and bathroom fans, removing dust with a vacuum about once a month is recommended. In the kitchen, the range hood filter should generally be replaced or washed every one to three months.
Q. When is the right time to replace a ventilation fan?
A. The typical service life is around 15 years. If you notice louder noise, unusual sounds, or reduced ventilation performance, it is reasonable to consider replacement. In a rental property, consult the landlord or property management company.
