Most of us have an idea on what an inverter does for refrigerators and air conditioners. It saves a lot of energy (and money) when operating these two notoriously power-hungry appliances. But for a washing machine?
Does a washing machine even use a lot of energy to warrant the use of an inverter? Is it even worth it to spend an additional ₱5,000 – ₱7,000 more to get that inverter upgrade?
In this post, we will give you some pointers on the differences between inverter vs. non-inverter washing machines so that you can have a more informed decision when buying a new washing machine.
- How a washing machine works
- How an inverter washing machine works
- Inverter vs. Non-inverter Washing Machine: A Comparison
- Other benefits of an inverter washing machine
How a washing machine works
Whether it’s a top-loading type or a front-loading type, a washing machine works by moving your clothes through water and detergent to loosen dirt and grime with the drum walls acting as the washboard.
When you load the laundry in your fully automatic washing machine, its sensors will detect how much the clothes weigh. With this information, the washing machine’s microprocessors decides how much time and water is needed for that batch of laundry.
As with the spin speed however, washing machines are designed with the assumption that you are going to load whatever is the maximum capacity your particular model can handle. Whether you are loading a 3kg or a 7kg batch on a machine that is rate for 7kg, the motor spin speed will be the same. Hence, a lot of power will be wasted.
Sure, you use the “gentle” setting if you want to wash a 3kg load on a 7kg-rated washing machine if you want to save a little bit of energy, but the cleaning performance will not be optimal. This is where inverters come in.
How an inverter washing machine works
Simply put, an inverter is a device that controls the frequency of the incoming electrical current that goes to the motor; this allows the washing machine’s motor to operate at variable speeds.
With this, an inverter washing machine can vary its motor speed to the most optimal level depending on the weight of the load that you’ve put in. This will allow the washing machine to use the least amount of power without sacrificing its cleaning performance.
This brings us to two questions: (1) how much will an inverter washing machine save you? And (2), is it worth the additional cost?
Inverter vs. Non-inverter Washing Machine: A Comparison
For this example, we are going to use two 10.0 kg fully automatic top load washing machines from Electrolux: EWT105WN (non-inverter) and EWT105WD (inverter). I chose these two models because apart from the color and the motor, these two are nearly identical.
As you can see, the inverter model has a 90W advantage over the non-inverter model. However, is it enough to justify the ₱7,000 price jump? Let’s take a deeper dive.
How much will an inverter washing machine save on your bill?
To compute the monthly electricity bill for these models, we will use the following computation:
(Wattage ÷ 1,000) x Hours of use x Power Rate = monthly electricity expense
Since the power rate is in kilowatt per hour (kWh) We need to divide the washing machine’s wattage by 1,000 to convert it to kilowatt (kW).
We will also assume that you will use your washing machine once per week for two hours (two loads – for whites and coloreds).
|Model||Energy Consumption (kW)||Power Rate (kWh)||Cost per Hour||Cost per Week (2 Washes)||Cost per Month (8 Washes)||Cost per Year (96 Washes)|
As you can see, the inverter model is 19% more efficient compared to the non-inverter model.
However, since the washing machine is not used for a prolonged period of time like a refrigerator or an aircon, the difference in energy savings is not as pronounced as the other two appliances.
Even if you use your washing machine for obscenely long hours per wash, it will take you a very long amount of time to recover the additional ₱7,000 you’ve invested for the inverter upgrade.
Doesn’t sound so appealing now is it? Well, there are some other non-monetary benefits that an inverter provides.
Other benefits of an inverter washing machine
One term that you often see lumped together with inverter washing machine is direct drive motor (DDM).
What is a direct drive motor (DDM)?
Most washing machines are driven by a system of belts and pulleys to transfer the power from the motor to the pulsator or the drum (belt drive). While this is cheap and easy to repair, it is noisy, inefficient, and suffers from a lot of vibrations.
As the name implies, direct drive motors (DDM) powers the drum or the pulsator directly; no belts needed. This provides the following benefits:
1. More efficient
Since the power is transmitted directly to the drums or the agitator, there is no energy lost between the motor and the belt, which improves its efficiency.
2. More durable
The belts and pulleys in the belt-driven system are susceptible to wear and tear because of friction. Since there are fewer moving parts in a DD motor, they are generally more durable than belt drive motors.
This is reflected in the manufacturers’ warranty policies; most inverter/DDM models have a warranty of 10+ years for the motor while it’s only 1 year for their non-inverter and non-DDM counterparts.
3. Less noise and vibrations
DD motors have a higher torque-to-weight ratio compared to belt-driven motors. Basically, that means that to reach a certain speed, a belt-driven motor has to exert more energy to make the washing machine tub (or agitator) to compared to a DD motor. This makes the DD motors more stable, and produce less noise and vibrations.
While inverter washing machines are truly more efficient compared to non-inverters, do you think that the energy savings justify the additional upfront cost of the inverter?
Also, are the perks of having a DD motor enough to make you want to buy an inverter washing machine?
I hope that we were able to provide you with insight regarding inverter washing machines. Are you planning to switch to an inverter model soon or are you still unconvinced? Let us know by commenting below!
Miguel Mores worked for 5 years as a member of the product management team for a home appliance company in the Philippines. He started 101appliance to answer the most common customer questions that he has encountered during his time in the industry. He now works in the digital marketing field and manages a small online bookstore on the side.