Carpet cleaning methods compared: steam, dry cleaning and shampooing
What hot water extraction, shampooing, low-moisture and dry cleaning each do well, what they don't, and which suits which carpet.
Cleaning companies tend to recommend whichever method they have the equipment for. It's useful to know what the real differences are, so you can ask better questions.
At a glance
| Method | Cleans deep? | Drying | Good for | Watch out for |
|---|---|---|---|---|
| Hot water extraction ("steam") | Very good | Hours, longer for thick pile | Most synthetic carpet, some wool | Too much water; heat on sensitive fibres |
| Shampooing | Moderate | Slow to moderate | Surface soil on robust carpet | Residue attracts dirt quickly |
| Encapsulation (low moisture) | Moderate | Fast | Offices, maintenance between deep cleans | Less effective on heavy soil |
| Bonnet cleaning | Surface only | Fast | Quick appearance improvements | Can leave soil deeper down |
| Dry compound (powder) | Moderate, near the surface | Very fast | Water-sensitive carpet | Powder residue; needs thorough vacuuming |
Hot water extraction
Hot water and a suitable cleaning solution go into the pile and are immediately extracted by vacuum. Because soil and solution are taken out together, it's usually the most thorough option. It's our main method, and you can read about it on our carpet steam cleaning page.
The trade-off is moisture. In Hong Kong's humidity, drying needs to be planned as part of the job.
Carpet shampooing
A rotating brush works foaming detergent into the carpet, which is then left to dry and vacuumed, or extracted. It was once the standard method, but it has fallen out of favour because detergent residue left in the pile can make carpet attract dirt faster. It can still work on robust carpet if it's followed by proper rinsing, but we rarely see a reason to choose it over extraction.
Encapsulation
A low-moisture polymer solution is brushed in, crystallises around the soil as it dries, and is vacuumed out later. It dries quickly and suits regular maintenance in offices. On heavily soiled carpet, it won't replace a deeper wash.
Bonnet cleaning
A spinning pad, or bonnet, absorbs soil from the top of the pile. It's quick and improves the appearance, which is why hotels sometimes use it between deeper cleans. It's not a deep clean, and if overused, it can distort the pile.
Dry compound cleaning
A slightly moist, absorbent powder is brushed into the carpet, where it attracts soil, and it's then vacuumed out. It's very useful for carpets that can't tolerate much water, including natural fibres. Vacuuming thoroughly matters, or powder may remain in the pile. Despite its name, "dry cleaning" a carpet usually involves some moisture.
Which method suits which carpet?
- Nylon or polypropylene fitted carpet: hot water extraction
- Office carpet tiles: low-moisture maintenance, with occasional deeper cleaning where the tiles allow
- Wool: gentle extraction or low-moisture methods, with wool-safe products
- Sisal, jute, coir: very low moisture or dry methods only
- Silk, viscose, antique rugs: assessed individually, often by a specialist
What to ask a cleaner
Ask which method they'd use and why. Then ask whether they'd vacuum first and rinse afterwards. If someone offers just one method for every carpet, ask how they'd handle wool or natural fibres. You'll learn a lot from their answer.
Want to see how our approach fits together? Read about our process, or if your carpet is very dirty, see carpet deep cleaning.
