Mini-Split Systems: Hope You Like Tubing


The radio is abuzz with ads for systems that condition (heat or cool) only the spaces you are using. No, they aren’t about baseboard electric heat. They are for a product line called mini-split or ductless mini-split systems. And unlike electric baseboard, they can heat and cool. Mini-split systems are an excellent choice in many heating and cooling situations particularly when no ductwork exists. So, what are they and should you use them in your home?

Let’s talk about the technology these systems use. In short, they are small heap pumps designed to treat portions as opposed to entire homes. They are highly efficient, often providing 33 SEER versus 15 – 16 SEER for a whole house heat pump. They get their name from the way they are built and installed; the compressor and condenser are in an outside unit while the fan and air coil are placed where you want to heat or cool.

Using variable speed components and sophisticated software, these units provide comfort to spaces over a much wider temperature range and for a lot less money than a regular heat pump. For instance, a conventional heat pump begins to lose its heating capacity between 32o and 17o. To make up the shortfall in heat production, the system turns on resistance heating strips. This can really increase your operating cost. Mini-splits can provide 100% output down to -5o, depending on the make, model and manufacturer.

These systems work just like a regular heat pump in that they move heat from one area to another. In the summer, they pump heat inside your home, via refrigerant, to the outside unit where it is discharged. In the winter, they capture heat from the outside air and bring it into your home, again via the refrigerant. It seems amazing to think these systems can provide heat on really cold days but they can.

You can replace window air conditioners, electric baseboard and wall heaters or simply condition space you haven’t before, say a bonus space over a garage. They are very flexible when it comes to possible applications.

Here are the components:

  • An outside unit much like a regular heat pump, just thinner.
  • Refrigerant tubes to connect the outside unit to the inside one.
  • Inside unit.
  • Controls; a thermostat and frequently a handheld remote.

The appearance of the inside units is where folks may find room to object. Manufactures try to make them as unobtrusive as possible but at about 30”x 12”x 8” they do stick out. I have seen floor mounted models from one company and also ceiling units. These ceiling units require some ductwork increasing installation costs.

Then there are the refrigerant tubes. Installation of these systems is very simple. Drill a 3 – 4” hole in the wall for the tubes and install the inside and outside components. Connect the power and you are ready to go. Just like the manufacturers try to make the inside units unobtrusive, installers try to do the same with the tubing. Typically they cover the tubes in a cover, either plastic or aluminum. To outward appearances, this looks like another downspout. Use mini-splits for your whole house and you’ll have a lot of “downspouts”…another area folks may not like.

Appearances aside, these are amazing systems. If you can get over the appearance issues, you can dramatically reduce your costs to heat and cool. Plus, they eliminate the expense of the expanding ductwork of an existing ducted system.

Got a project where the mini-split might fit the bill? Give your favorite contractor a call to see how they can work for you. The savings and improved comfort are sure to keep you happy.