There are several answers as well as considerations you need to consider regarding how often you should clean your carpets. They are what I call blanket answers. Answers that are designed to cover everyone. The problem being no one answer is realistic for everyone.
All the major carpet manufacturers recommend every carpet should be cleaned on an annual basis but require that all carpets are professionally cleaned at least once every two years to keep the warranty in force for the carpets. Their reasoning for this is that professional cleaning will help remove deeply embedded soil particles. It is these particles that could remain in the carpet and be a primary cause for causing fiber loss due to the slow cutting of the fibers at their base. This is very true.
The IICRC, http://www.iicrc.org and the CRI, https://www.carpet-rug.org both of which are organizations that are involved in both carpet cleaning, certifications within the industry as well as ongoing education both have a similar approach. Their thought is to clean carpets once per year with a little variance based upon use.
I like to take an honest approach. One that is tailored for each situation. First, you need to consider if a warranty is important to you and what it covers. In my 50 years plus of experience in the carpet cleaning industry in the greater Boston area, I have never come across an issue that was covered by a manufacturer's warranty. Not to say it never could happen, just I’ve never seen it. As far as cleaning by a schedule, I feel it is more important to consider other factors as well. Yes, a carpet should be cleaned regularly but there are also other considerations.
What is the area used for, a family room that receives heavy daily traffic, a quest bedroom, that rarely sees any use, or perhaps a formal dining room carpet that is put to use twice a year? Next, consider your lifestyle. One child with no pets versus 6 children, two dogs, and a cat. This all plays an important part in your consideration as far as how often you should clean your carpets. Never mind the visual appearance of a heavily used rug with several children and pets or perhaps a sloppy husband.
Another issue that is usually not considered but should be is the exterior environment. Do you live in the suburbs where the air is considered to be clean? Or do you live in a major city like Boston or New York, where there is a tremendous amount of soot from car emissions that get filtered into the house? This soot can be very acidic and can cause some serious soiling issues if left to accumulate on a carpet.
Lastly, we should not forget the health issues. Most homes are run on a very relaxed policy of wearing shoes both in and out of the house. Everything that is stepped upon outside gets tracked inside. This, along with a few food spills not properly cleaned up or an occasional pet accident all factor into the overall consideration of the cleaning frequency needed. Believe me, this can cause quite an unhealthy environment. Another consideration is if any member of the family suffers from allergies. Dust, dust mites, and bacteria can all lead to some pretty unhealthy conditions. You may want to read our blog on dust mites. http://www.alecscarpetcleaning.com/blog/entry/all-about-dust-mites. Another good read would be our main page on carpet cleaning at http://alecscarpetcleaning.com/carpet.
So, as you can see, there is a lot to consider. Even the frequency that carpets are vacuumed as well as how well they are vacuumed plays a part in this overall picture. We try to educate our clients so they can make responsible decisions for themselves. This is why we have a reputation for being Boston’s best carpet cleaner.