#4) THE TWO BASIC TYPES OF STEAMERS
When you are talking about dry vapor steam cleaners there are two basic types on the market today. One, the more dependable single tank systems. Two, the easy fill dual tank, continuous fill systems. Both use as little as one gallon of water an HOUR making them extremely usable indoors. Both the single tank and dual tank dry steamers have their strengths and weaknesses. Note, there is a third kind of steamer, a wet steam pressure washer. It produces super heated steam but instead of being dry, it uses close to 1 gallon of water a minute. For more on industrial wet steaming click here.

4-A) SINGLE TANK STEAM CLEANERS: Single tank vapor steam cleaners are the tried and true standard bearer of the steamer world. They were the original design for steamers. Never buy a steam cleaner with a boiler less then a 2 liter water capacity. 3 liters is perfect, more is better.

SINGLE TANK PROS: A single tank steamer is amazingly simple in its design. This simple design makes the single tank system inherently more dependable. If you are looking for a powerful system that should run trouble free for years and years it is a single tank system. Another nice thing about the single tank systems is that they tend to give a dryer steam. As your using the system the steam gets dryer and dryer. This is due to the fact that as the water level gets lower, it also gets further away from the steam outlet port at the top of the boiler.

SINGLE TANK CONS: The only down side to a single tank vapor steam cleaner is that when it finally does run out of water you are required to shut down the system, cool it off, refill it and wait for it to warm up all over again. However, if you get a system with a good size boiler, there is a good chance you will get tired of cleaning long before it runs out of water that day.

4-B) DUAL TANK STEAM CLEANERS: Dual tank, sometimes called continuous fill or continuous flow vapor steam cleaners are the latest technology in vapor steam cleaning. A continuous fill system allows you to add water "on the fly". You will never have to shut the unit down to refill it and when you add water you can get right back to work. Never buy a continuous fill system if the boiler is less then 3 liters. The refill tank can be any size.

DUAL TANK PROS: This dual tank system features one boiler and one refill tank. This refill tank keeps the boiler topped off with water at all times via a high pressure injection pump. What this means is that you can add water at any time without shutting or cooling down the machine. Truly a time saving concept. If you are a contractor or run a business where you intend on using a steamer several hours every day, you should consider getting a continuous fill steam cleaner. In the business world time is money and this type of unit will save you plenty of time.

DUAL TANK CONS: Although the dual tank steamers are convenient there are some down sides to them. They have a reputation for being considerably less dependable then a single tank system. The reason for this is simple. A dual tank system not only has a boiler, switches and circuit board but it also has an extra tank, extra lines, a high pressure transfer pump, some have in line filters, special sensors to detect the slightest drop in water level and extra safety features. All these extra parts combined with super high temperatures result in a somewhat less dependable steamer. Continuous fill systems also tend to run a little wetter. This is due to the fact that the boiler is always full and the bubbles are popping close to the top of the outlet tube. That being said, we are only talking 1% or 2% wetter. All this being said I would rather a continuous fill system if I were in business but it really depends on how many hours a day you plan on using it.