How does drum capacity affect spin efficiency?

I occasionally receive questions asking about how the size of the drum affects spin efficiency. This is quite a technical question and not something people are generally aware of. I’m pretty sure that the size of the drum does make a difference due to the physics of it. I know that in gearing, the smaller the wheel the faster the revolutions so presumably the larger the drum the faster the motor has to spin to achieve the same revolutions.

I have done a little bit of research and found that the larger drums do appear to have a better spin rating compared with washing machines spinning at the same speed but with smaller drums. But there are anomalies, which means it’s not easy to make a direct correlation between the size of the drum and it is spin efficiency.

For example there is a Bosch 1400 spin washing machine with a 6kg drum rated B for spin efficiency, but there is also a Hotpoint 6 kg drum washing machine that spins at 1600 despite having the same 6Kg drum and spinning at 1600 rpm it is also only rated the same B for spin efficiency. This shows there is more to spin efficiency than the size of the drum and the spin speed. The design of the drum, how many holes, what size holes, the pattern of the holes and also exactly how long it spins for must also have an effect.

Within the time I spent researching washing machine stats I found that most washing machines with a 6 kg drum and 1400 spin speed were rated at B for spin efficiency, where as most washing machines with 8 or 9 kg capacity drums spinning at the same 1400 rpm were rated A for spin efficiency. I don’t see this as conclusive proof because there are several anomalies but it does tend to give credence to the idea that the larger the drum the more centrifugal force and the greater the spin efficiency.

Here are some of the ratings I observed –

At the end of the day there’s less difference between A spin efficiency and B spin efficiency than most people are likely to assume. Here’s an article I wrote looking at the difference between tumble drying loads spun at different spin speeds and how much extra that is likely to cost – Washing machine spin speed efficiency figures and drying costs

Related:

• Washing machine spin speeds (Washerhelp article)
• Are Washing Machine Spin Speeds A Con? (Forum discussion. Topic is closed but you can comment on this article (below) if you want to add something)

Find out which are the best washing machines – Which? Best washing machine brands (NOTE: The Which? reviews and consumer advice is available immediately online and a 30 Day Trial offer is available for just £1)

Written By - Washerhelp on February 24th, 2009 with no comments, yet - What do you think?
__
Read More Articles on Washing Machines & Washer Dryers |  Subscribe | Please Report any broken links - pretty please :-)

Why not add your comment? click the comment link above or scroll down to the comments box

Related articles

• 10% and 15% discount codes for Comet US refrigeration appliances (January 28th, 2010)
• Hoover stacking kits (January 20th, 2010)
• What should I do with the old hot water tap when connecting a cold fill washing machine? (January 6th, 2010)
• Washing machine won’t spin just one item or very small loads (October 13th, 2009)
• Why don’t most modern washing machines last very long? (August 9th, 2009)