If you don't have central air conditioning in your home, window air conditioners can become your best friend during the summer months. But not every room has windows large enough – or windows at all – to accommodate a window-mounted unit. You aren't relegated to a summer under a ceiling fan.

There are a couple of cooling solutions in small rooms where window units aren't possible.  Understanding how each one functions can help you in making a purchase decision and in advising an appliance repair person of what might be wrong should a problem arise.

Portable Air Conditioner

A portable air conditioner is a small unit that can be easily moved between rooms for cooling. The unit looks a bit like a small upright window air conditioner.

The front of a portable air conditioner contains the cool air vent, the control panel and display, and might include the handle used for pulling the unit around. On the back of the unit, you will find the key air conditioner components.

A portable unit has two air inlets on the back – one the condenser and one the evaporator – which are how warm air enters the machine and is cooled. There's also an air filter, which needs to be cleaned or changed regularly, and a stoppered drain hole. If you use the unit regularly, drain the moisture out at least once a week over a bathtub drain.

You will need a way to vent the exhaust hose of the unit out of the room you are cooling. This can involve running the hose out a small window or a door that leads outside. If neither of those exists in the room, you will need to create a small hole through the wall to outside so that the hose can vent through the wall.


A packaged thermal air conditioner, or PTAC, is the type of wall unit most commonly seen in apartments or hotel rooms. The unit has to be mounted into a wall so that the unit's rear vents can aim outside. Some models of PTAC don't require any draining due to the condensate being thrown back on the heated condensing coils to dry.

The sheer size of a PTAC unit doesn't make it the best option for a small room that could be serviced by a portable air conditioner.

However, if the small room is a rental space with an adjoining bathroom, a PTAC unit could be a selling point when you're trying to attract new renters. The renters will have the ability to control the room temperature to their liking and the output will be stronger and reach further than a portable unit. Click here for more info about AC.