People are so used to central air conditioning systems that they imagine they’re the only effective way to provide cooling to an entire house. Window air conditioners have obvious limits: in order to cool a house, they need to be placed in every room, and not every room has an available window that works with them. Window ACs also struggle to cool larger rooms. For example, a single window air conditioner won’t do much for a living room.
There’s another option for whole-house cooling, the ductless mini split heat pump. These systems use wall-mounted air handlers to send cooled (or heated) air directly into spaces. They connect through a small hole behind them in the wall to the outdoor cabinet that exhausts heat in the summer.
Is installing a ductless system in a house an effective method to keep cool during our hot summers? Or is it always inferior to a central HVAC system?
The cooling capabilities of the wall-mounted air handlers
Let’s start with the cooling you can receive from one of the air handlers in a room. Each of these units contains its own refrigerant coil to absorb heat to cool the air and a blower fan to send it out. Unlike a window AC, it doesn’t need to house a compressor or exterior coil—that’s all contained in the separate outdoor condenser, which the air handler connects to via a refrigerant and power line. A single air handler has 12,000 BTUs of cooling power, more than most window ACs. This provides enough cooling for a space of 450 to 500 square feet, which can handle the majority of rooms in a house without trouble.
The number of air handlers
So one of the air handlers can take care of the cooling requirements of a room. But how many air handlers can a single ductless mini split sustain?
The answer is up to eight air handlers per outdoor condenser unit. This means a home can have up to eight different cooling “zones.” If you have a four-bedroom house, you can have cooling zones for each bedroom and still have four more zones you can cover: the living room, the kitchen, the dining room, and a den/office. Eight zones is enough to handle the comfort needs of the majority of homes, and it’s easy to add a second condenser to accommodate larger homes.
Yes, a ductless system can cool your whole house
You probably already realized this by reading what we wrote above—but in case you skipped down to the bottom to peek at the answer, here it is. Ductless systems are excellent choices for homes without ductwork that have to rely on window air conditioners for comfort. Because ductless mini splits are a type of heat pump, they also provide heating, making them great year-round solutions.