Valley Home Services technician installing a heat pump.

While shopping for a new HVAC unit for your home you might have come across units called “Ducted Mini-Splits” and “Ductless Mini-Splits.” If you’re not an HVAC specialist or you’ve always lived in a home with centralized, ducted heating and cooling, you may not be familiar with these or how they work.

What a mini-split is, and how it works.

A mini-split heat pump unit can both heat and cool your home. It is made up of two parts, one that remains outside and an inside component. The outside component pulls in outside air and pulls heat out of it via compressed refrigerant. How do you pull hot air out of a cold Maine night? By getting the refrigerant significantly colder than the outside air. Heat is pulled from the comparatively warmer outside air into the refrigerant. It is then sent through a small refrigerant tube into the inside part of the heat pump. Air is essentially blown over the heated refrigerant to force warm air out into the room.

This is a highly simplified, layman’s version of the heat exchange process. All you really need to know is heat is transferred from the outside air while in heating mode. This process is reversed in cooling mode, which means heat is pulled out of the inside of your home.

Mini-splits make great additions to new or old homes because of how easy they are to install with or without an existing HVAC framework as long as there is access to an outside wall. They work best on a small room-to-room scale. They’re an excellent solution if you have different temperature needs for different rooms in your home. For example, if your kitchen runs hot but your bedroom is always cold, a mini-split could provide a solution. Each room has an air handler, allowing you to control each room’s temperature separately.

Ductless Mini-Split Versus Ducted Central Air

  • Ductless Mini-Splits are great for older buildings that don’t already have ducts, home additions or adding temperature control to a part of your home that didn’t have it before (like the garage). The inside and outside components of a ductless mini-split are connected to each other through a wall (a small hole is required for power, refrigerant line, control wires, and condensate drain line).They are considered particularly energy-efficient compared to other heating and cooling solutions.
  • Ducted Mini-Splits use a vent system to deliver temperature-controlled air to a specific room or a series of rooms via a short run of ducts rather than whole-home ductwork. Some find them more aesthetically pleasing because all interior components of a ducted mini-split are concealed (no bulky air handler on your wall).They’re an excellent solution if you want the zoning control that a mini-split system offers without wanting to have the air handler visible in a room. However, the installation of the ducts can make the job more expensive, time-consuming, and messy. Installation options may be more limited compared to ductless mini-splits.

Why Are Ductless Heat Pumps More Energy Efficient Than Traditional Central Air Systems?

All heated and cooled air circulating through ducts should ideally not leak out into uninhabited spaces in your home (attics, crawlspaces, etc.). But ductwork is rarely perfectly airtight. Even if it started out perfect, leaks will form over time, meaning some of the temperature-controlled air escapes and is wasted. Ductless heat pumps don’t have that issue since there’s no ductwork.

The biggest factor affecting energy efficiency is the source of heating and cooling. Furnaces, boilers, and other traditional central air heating solutions burn some form of fuel to generate heat. Heat pumps do not burn fuel or derive heat from heating coils – they simply transfer heat from outside or inside (depending on mode). This requires far less energy than traditional combustion-fueled heat generation.

However, this same benefit can be cited for central air heat pumps – so what makes mini-splits better? The answer is zoned heating and cooling. Instead of expending energy to control the temperature in the whole building, including guestrooms, offices, bathrooms, or dens that are empty, you’re only paying to heat or cool the rooms that you’re occupying. This targeted temperature control can drastically cut your utility bills.

Mini-Split Installation in Maine

Ductless heat pump purchasers understandably want their heat pump installed by an experienced heating and cooling specialist. Valley Home Services is a local, family-owned business that has been operating in Hermon and Bangor, Maine, since 1981 and is now in the Brunswick area. We have years of experience and are a Fujitsu Elite Dealer. We proudly install Fujitsu heat pumps as well as Honeywell generators.

You can learn more about our heat-pump installation services online, or feel free to contact us at (207) 945-9008 for a consultation on your home comfort system.