The smaller footprint makes them ideal for homes where space is limited or who need a non-obtrusive cooling system. Energy Star is a brand that consumers want, so it comes at a cost. You do get used, just like if you were to get used a new posters. They can be moved from room to room and provide cooling only in the areas that are needed. You may not pay any additional fees if you purchase. Portable ACs that have only a single hose will not be suitable for rooms requiring a large amount of cooling. Maintaining them in good working condition won't have a negative impact on your wallet, barring the normal wear and tear repairs that any cooling solution over time will require. Some models have a pan that must be emptied each time the unit is filled with water. Btu, or British Thermal Units, measures cooling capability. With a little planning, you can easily find the ideal portable air conditioning unit for your upstairs area. Second, the window units can be easily stored when they aren't in use. You can save energy by turning on your mini-air conditioner in a particular room, such as your bedroom or office. Your caterers, servers and DJ will all be affected by the heat.