First question.  Why should I purchase a portable instead of a truck mount carpet cleaner.  It's a money thing.  If your just starting out and you have the money for a heavy duty van, advertising, expenses and the truck mount then go with a truck mount. A person that cleans properly using the proper procedures and uses good quality chemicals can do just as good of a job with a portable than a person with a truck mount.

With so many carpet cleaning extractors out their which one do you choose ?  I can point you in the right direction and give you my opinions but this is a decision you will have to make depending on a few questions you must ask yourself.  What type of area will you be cleaning, inner city, suburban, new or older homes, mobile auto detailing or stationary detailing, commercial cleaning, hospitality, food service or you may want to do what ever you can get ?

The reason this question is very important is that most more powerful units need to be plugged into 2 outlets that are 20 amps and must be on separate breakers.  Why ?  Because most heated units pull over 2000 watts just with the heater.  Then you have the dual vacuums (2 each vacuum motors) and the pump.  All of this power is split between 2 cords.  If your doing inner city older homes you will have a problem finding 20 amp outlets.  Most commercial and hospitality should be OK.  Newer homes usually have 20 amp outlets in the bathrooms and kitchen.  You can also use the machines that have heat without the heater on to cut the amperage draw considerably.    Our company's' belief is that a person using the standard 25' hose set, that most carpet cleaners use, would do a good job with a 100 psi, dual 2 stage with heat unit.  Read about cleaning carpet  and read section on carpet restoration.

If you think you can handle the extra amperage go with the 3 stage vacuum units with heat and 100 psi pump.  The three stage vacs give you as much vacuum as a truck mount running long hoses. Some contractors have told me they have made splitters that plug into the 220 volt outlet used for dryers.  These are easily made for under $50.00 and could handle a powerful unit.  I recommend having an electrician put it together for you.  Some contractors have told me they have a generator in their van to run one or both of their cords.  

Another question would be how will I be using the machine ?  Is this for a homeowner for him or herself,  for a part timer looking to make extra money, for a back up machine, for a janitorial company using it on occasion or for the full time carpet cleaner. The below is my suggestions and is only a suggestion.  I do recommend when ever possible to use a heated machine.