Heat Pumps (Mini-Split)
Our brand new Mini-Split Guide is available here! Our Mini-split expert Everett Walsh will be happy to review this information with you if you are in the market for a new mini-split heat pump.
Mini-splits Heat Pumps are air source heat pumps that have revolutionized heating and air conditioning around the globe – they are the fastest growing and largest part of the global HVAC market. They can heat a room or a whole house at half the operating cost of propane heating and provide cooling and dehumidification (“dry mode”) too.
We have installed and serviced all heat pump brands currently on the market. We have received factory training from Daikin, Mitsubishi, and Fujitsu.
After careful consideration of the reliability, serviceability, economy, and return on investment of all of the major heat pump brands, we have chosen to offer Mitsubishi heat pumps.
Our Mini-Split Guide (see box on right) outlines why we chose Mitsubishi, how heat pumps can work in your home, and the various rebates, incentives, and loans available to homeowners on the Vineyard. Click here for the Mitsubishi rebates.
They come in two parts – an inside “head” that is mounted in the room and an outside “heat pump” that lives outside – and are connected by two copper pipes (the “line set”) that carry refrigerant between the inside and outside units. The inside “head” is most often located on an outside wall (either high near the ceiling or low near the floor using the new console type) and has a small quiet blower to move air around the room. Heating, cooling, and dehumidification can be controlled by a hand held remote or by a wall thermostat (wifi versions are available too).
Their amazing efficiency is based on using a small compressor and fan in the outside unit to capture the solar energy in the outside air during the heating season and to remove summer heat in the room during the cooling season.
In the winter, they are able to extract this solar energy and use it to heat refrigerant up to 180 F. The heat pump sends this heated refrigerant into your home through small copper pipes (called the “line set”) to an inside unit – either a wall mounted “mini-split”. This wall mounted inside unit has a fan or blower in it which uses the heated refrigerant to heat the air in the room. Then the cooler refrigerant is sent back outside to the air source heat pump to repeat the cycle.
In the summer, the refrigerant flow is reversed and the heat from the room is absorbed by the refrigerant and sent outside via the copper pipes. The outside heat pump then rejects this heat to the outside air.
Because these units use outside air and free solar energy as their source of heat, there is no expensive geothermal loop to install.
They are also an excellent match with solar electric PV panels.
Because these units use outside air, they will frost up in the winter during normal operation. This means that periodically the system will stop heating the air inside so that it can defrost the heat pump outside. Additionally, these heat pumps will have reduced heating capacity as the outside air gets colder. This means that sizing of the air source heat pump for the heating load on the coldest day of the year is very important. Finally, because the outside heat pump depends on a fan to pull outside air through the heat pump, it is critical to keep the heat pump elevated above the snow, usually on a stand.
Our goal is to be Martha’s Vineyard’s premier plumbing and HVAC shop – we appreciate the opportunity to service, install, and rescue your mini-split heat pump system!