How Much Cheaper Is a Swamp Cooler Vs. Central Air?

Window-Mounted Evaporative Coolers

• Evaporative coolers for residential use are usually small, window-mounted appliances -- sometimes called "window units" -- that can be installed one to a room. Prices vary according to the power of the unit, and according to additional features such as programmable thermostats, timers, and remote controls. Multiply the cost of one window unit by the number of rooms you plan to cool to get an idea of the total installation costs for the entire home.

Large Evaporative Coolers

• Large evaporative coolers use the same technology as window units, but one unit serves an entire home. This saves the homeowner from needing to purchase a separate unit for each room. These units are much more expensive than individual window units, on average, but they still only cost roughly half as much to install as a central air conditioning system. The chief reason for the price difference between these and central air conditioning is that the technology used for evaporative coolers is much simpler.

Energy Costs

• A key consideration when weighing the costs of central air against individual evaporative units is the energy usage involved in operating each. Large evaporative coolers use about half as much energy, on average, as central air conditioning units. For small window units servicing one room at a time, calculating energy costs is a bit more difficult, since occupants can control when they are on or off. In general, however, even using multiple window units tends to be less expensive than central air conditioning so long as the window units are well-maintained. Invest in units with programmable thermostats that turn the evaporative coolers off when the rooms reach a predetermined, comfortable temperature to help prevent energy waste.

Maintenance

• Proper maintenance is key to controlling costs. Neglecting evaporative coolers can compromise their energy efficiency and lead to excessive energy usage. Evaporative coolers work by passing outside air through a damp pad that cools and adds moisture to the air; this pad needs to be replaced regularly in order for the cooler to work efficiently. For a whole-house evaporative cooler, sets of these pads cost around $20 to $40 as of publication and need to be replaced once or twice per season. For window units, the pads are much smaller and therefore less expensive.