Ductless Mini Split Heat Pumps

Fujitsu Air Source Heat Pump

Fujitsu Air Source Heat Pump

Most of the world, and the lower half of the US use ductless heat pumps as their primary source for heating and cooling. These systems use refrigeration technology to transfer heat from the inside to the outside in cooling mode, and in reverse in the heating mode.

Heat Pump technology is ready to transition Maine away from dirty, expensive and imported oil and into highly efficient electric heat.

Over the last several decades, this technology has improved significantly, getting more and more efficient, and working at lower temperatures. We now have ductless air source heat pumps that work down to -17 degrees and will create heat efficiently all winter in Maine.

How Efficient is it?

Every unit of electricity required to run the fans and compressors in a heat pump creates more than one unit of heat. The ratio of energy in to energy out is called the Coefficient of Performance, or the COP for short. A COP of 2 means that for every unit of energy that goes into the heat pump, two come out. The average efficiency of the Fujitsu Halcion heat pump through an entire heating season in Maine will average a COP of about 2.7. That is like buying oil at $1.90 a gallon.

Supplemental Heat Pumps

Ductless heat pumps in a supplemental roll don’t need to heat on the very coldest night of the year and they don’t need to heat the entire house on very cold nights. The back-up systems can take over in colder, remote areas of the home and when it gets very cold outside. If a system is supplemental, we can use the Fujitsu, shown above, which works all the way down to -13 degrees, a temperature rarely ever reached in Maine.

Air Source Heat Pumps for Full Home Heating.

It’s harder to design an air source heat pump system for 100% heating than it is to design one for supplemental heating. The system needs to work even when the temperature dips down to -17 degrees, and it needs to heat all corners of the home. In order to get an air source heat pump to meet the demanding needs of 100% home heating, an energy audit is often required to dial in the heating load. Insulation upgrades are often necessary to bring the heating load down and comfort up. We now have air source heat pumps such as the Mitsubishi Hyper Heat that work even when the outdoor temperature is -17 degrees and can displace about 600 gallons of oil a year.

Unlike boilers, heat pumps don’t scale well. The bigger the heating load, the more the system costs. Bigger houses with large heating loads and more rooms are best served by an automated pellet boiler.


Installing a Fujitsu Halcion heat pump for space heating and cooling is simple, works in most homes and will offset a significant amount of oil. The Fujitsu Halcion air source heat pump comes in three sizes; 18, 24, and 36,000 BTU’s. Each outdoor unit can connect to up to 4 indoor units. Each indoor unit acts as its own zone.

Installed costs vary on the number of inside units installed, the size of the outdoor units, the complexity of the installation and a number of other factors. However, some typical prices and the fuel they should offset are listed below.

18,000 BTU system with one zone    –    $5,000 installed   –    Offset 288 gallons per year

24,000 BTU system with two zones    –    $7,000 installed    –    Offset 384 gallons per year

36,000 BTU system with three zones    –    $9,700 installed    –   Offset 570 gallons per year