Ductless air conditioning—A better way to keep cool
Consider a mini-split system for your home cooling
If you’ve considered upgrading your existing system or adding air conditioning to your home, you’ve probably realized there’s a large gap in the available options for home cooling. At one end of the spectrum are the small, relatively inexpensive window air conditioners that seem to have moved along noisily with few advances in technology since they entered the mainstream market in the 1940s. At the other end are large, quiet (as long as you’re inside) central systems designed to hook into existing central ventilation ducts.
What do you do if you want something in between? What’s available for houses that have no ducting? Isn’t there a more efficient way to cool your home?
Positioned between the extremes of window-mounted units and central systems is an air-conditioning technology that’s still new to most Canadians. Ductless air-conditioners, also called mini-split systems, are a newer approach to air conditioning developed in Japan, which use a type of heat pump technology to efficiently deliver cooling action to independently controlled zones in your home.
Ductless air-conditioners are called mini-splits because the two main halves of the equipment are separated by distance. One half is the compressor, which sits outdoors all the time, just like the compressor on a central air-conditioner. The other half of the ductless system, the indoor air-handling unit, is wall-mounted and connected to the compressor via a pair of hidden pipes. This is the unique feature of the mini-split approach.
Think of the indoor component like a radiator that delivers cold instead of heat. It can be located as far as 75 feet from the compressor and without losing power or efficiency. Noise and vibration never get anywhere near the inside of your home, and cooling action can be delivered high up on any wall for maximum benefit.
Typical mini-splits include two or three indoor air-handling units to deliver cooling throughout your home. Hook up is technically easy, requiring no ductwork and only a three- or four-inch hole drilled through an exterior wall.
Besides offering an air conditioner option that’s sized to fill the gap between central systems and window air conditioners, ductless systems have another advantage, too. They save money through lower electricity consumption. This happens in two ways.
Since the cooling action of a mini-split is delivered to several independently controlled areas in your home, it’s possible to selectively cool different zones depending on the time of day. By focusing cooling action in bedrooms at night, for instance, and living areas during the day, you can save substantially by reducing the amount of total air cooled. And added to this there’s another energy advantage, too.
According to the U.S. Department of Energy, typical residential duct systems can lose a staggering 25 to 40 per cent of the heating and cooling energy supplied to them by a furnace or air conditioner. This happens because of leaks within the ducts, especially those drawing warm air back into the system to be cooled. Add to this the fact that the metal ducts themselves must also be cooled before you feel any benefit, and you’ll see where the energy losses come from.
Operating without all that sheet metal has its advantages. For duct-free houses heated with electric baseboard heaters or radiant in-floor heating, mini-splits offer cooling action that simply can’t be achieved with central air. Ductless systems also eliminate the risk of criminal intrusion into the home that window air conditioners create. Some systems are even designed to operate in reverse, supplying heat during cool weather. For homes without ducts, this can mean getting rid of those baseboard heaters, resulting in year-round energy savings.
At the moment, ductless, mini-split air conditioners are relatively new, and this means that a higher profit margin is built into their sales and installation. Currently, the cost-per-unit of cooling capacity is roughly one-third more than you’ll pay for central air. Despite the premium you might pay for new technology, the energy savings of mini-splits mean they’re worth considering. This is just one of a handful of technologies that let us do more with less energy while enjoying a better life in the bargain.