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Ductless Air Conditioning

Adding central air to house without ducts

Richard Trehewey holds a toilet

I saw a ductless air conditioning system used in an older house that did not have a forced air furnace. How does this work?
Mark, North St. Paul, MN


Richard Trethewey replies: A ductless air conditioner, also called a mini-split system, has two major components: a unit mounted on an inside wall that delivers cool air to the room and a unit mounted on the outside of the house. A pair of refrigerant lines run between the two, one delivering electricity, the other taking away condensate (water). The system also has thermostatic control and a variable quiet blower.

If your house already has insulated ductwork, air conditioning can be added to the existing furnace. If your house is without ducts, look into a high velocity mini-duct system. If you are looking for the "oasis theory" of cooling one room as opposed to a whole house a split type is a good solution. A split system has several advantages over a traditional window unit, first and foremost a thermostat that can keep the room at a constant, comfortable temperature instead of blasting on and off. In addition, you don't have to move a spilt system in and out of the window as the seasons change, and you don't have the open-window security concerns of a moveable unit.



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