Ductless Air Conditioning and Heating Frequently Asked Questions
Ductless air conditioners and heat pumps are also called mini-splits, wall mounted splits, or duct-free systems with certain manufacturers or unitary air-source air conditioners and heat pumps.
Q: What makes up a ductless mini split system?
A: A ductless mini split system is an indoor fan, referred to as the head, and an outdoor compressor unit. Connects with the compressor by copper tubing and electrical wiring that’s passed through a 3-inch hole. The compressor looks like a small central air condenser and can cool and heat one or more rooms.
Q: What is a heat pump?
A: A heat pump is an air conditioner that simply reverses the flow of refrigerant between the outdoor and indoor units. Please note that all heat pumps are also air conditioners. When heating is called, the heat from the outdoor air is absorbed by the outdoor unit, then more heat is added by the compressor then pumped into the indoor unit. After being ejected into the room, the colder refrigerant is pumped through an expansion valve causing the refrigerant to become very cold. That is why some heat pumps can still heat homes when it's -13°F outside.
Q: What are the main components of a ductless air conditioning system?
A: A ductless air conditioning system is quite simple and includes an outdoor unit, indoor unit(s), refrigerant line-sets, power and controls wires connecting them. The outdoor unit includes the condensing coil, the compressor, the expansion valve and a fan to get airflow through the condenser coil. The indoor unit includes the evaporator coil and a fan for airflow. The line-sets connecting the indoor and outdoor units are made up of heat insulated copper tubing for transferring the refrigerant.
Q: What are the advantages of installing a ductless mini split system over a central air conditioning?
A: For starters, you’ll get:
More control. With central air, you must cool an entire house even if you want only one room cooled. Offering room-by-room control, ductless mini split systems cool (or heat) only the areas you want. Room-by-room temperature control alone produces savings for many homeowners.
Ease of use. Most homes either lack zones or have complex zoning systems that make them expensive or confusing to operate. With a ductless mini split system, multiple heads make zoning as simple as setting a TV remote control.
Less energy waste. Ductless mini splits use inverter technology which allows the system to continuously adjust its speed to match the heating and cooling demand of the home. Additionally, the ducts in conventional systems can lose up to 25 percent of the energy produced; ductless mini split systems conserve 95 percent, because the energy is transported through insulated lines.
Better aesthetics, easier installation. Retrofitting homes for central air conditioning requires cutting holes in walls, floors and ceilings or losing valuable closet space to make room for ducts. A ductless mini split system requires just a three-inch hole in an outside wall to connect the compressor and head.
Q: How noisy is a ductless mini split?
A: In general, the sound generated by a head is equivalent to whispering in a library (between 21 and 30 decibels). The sound from an outdoor unit is more like normal conversation (60 decibels) but is less than a conventional air conditioning condenser.
Q: Is a ductless air conditioner more efficient than a central air conditioner?
A: Mini-Split Ductless Systems are:
- More energy efficient than traditional HVAC Systems
- Use only the exact amount of energy needed to maintain comfort
- Are up to 40% more efficient than window units
Q: What is SEER?
A: SEER is an abbreviation of Seasonal Energy Efficiency Rating. It is a measure of the seasonally adjusted cooling output of a unit divided by the energy consumed. The higher the SEER rating, the more energy efficient the unit. The minimum SEER rating for new air conditioners is 13 SEER. SEER ratings have recently replaced EER ratings in popularity which are similar, but without the seasonal adjustment. EER ratings are usually lower than SEER ratings.
Q: Is one ductless air conditioner able to cool the whole home?
A: Yes, if the indoor unit is properly placed such as at the top of the stair landing on the second floor, then the airflow can be adjusted to completely cool the 2nd floor and the remaining cool air travels down the stairs to the 1st floor. Through natural convection, the whole home can be cooled quickly.
Q: How long can a ductless air conditioner last?
A: If the unit is properly maintained than you can expect more than 20 years of life.
Q: What maintenance and service do ductless air conditioners require?
A: It is very important to keep the indoor unit filters clean. These filters are located in front of the evaporating coil behind the front cover. The outdoor units need to be cleaned regularly, especially the coil which can trap leaves, dust, etc. All that is required is a soft brush (as to not damage the coil) and sweep the coil until it is relatively free of any obstructions.
Q: How Big Is a Ductless System, and How Do I Know What Size to Get?
A: Ductless systems are designed and sized specifically to each project at hand. For instance, if you are installing a ductless multi split system with two indoor air-handling units (one for an attic conversion to a home office and the second to heat and cool an attached garage, for example), each air-handling unit should be sized specifically to the zone where it's installed.
The sizing process should only be conducted by an experienced and reputable HVAC contractor. Correct sizing of your ductless system affects purchase and installation costs, and the monthly energy bills and maintenance for the life of the system. Work closely with your contractor to design a ductless system that suits your project.
Q: How Long Does It Take to Install a Ductless System?
A: The typical ductless mini split installation takes one day. If your ductless configuration includes multiple zones, the installation could take two days.
Q: Do Ductless Systems Use Less Energy Than Other Systems?
A: Ductless systems are designed for energy efficiency at every operation. These are some of the features that drive ductless performance:
- Inverter-driven compressors operate at variable-speeds to prepare and pump refrigerant at optimal levels. Variable speeds mean ductless compressors use the minimum electricity required at any given time, to match the heating and cooling load of the zone (room or area in a home).
- High-efficiency refrigerant operates under greater pressures, delivering super-heat and super-cool heat exchange at the indoor and outdoor coils. This results in less electricity consumption, and the ability to meet heating demand to single frigid digit temperatures.
- Each indoor air-handling unit delivers independent temperature control. This provides a zoning system for convenience, comfort and exceptional efficiency. You may heat and cool individual zones as needed.
- The fans inside the indoor air-handling units use much less electricity than large fans of conventional systems.
Q: What Situations Are Ductless Systems Designed For?
A: Ductless systems are expandable to meet the heating and cooling needs for one room (mini split), multiple rooms (multi split) and entire whole-home heating and cooling systems (modular configuration). These are some examples:
- Space heating and cooling for difficult-to-reach areas, or anywhere you would like supplemental heating and cooling.
- New additions to the home.
- Remodeled spaces, such as converting attic space to a home office or bedroom, converting a garage to a workshop, a basement to a family room, a deck to a sun room and practically any home-improvement project on the drawing board.
- Vacation homes and rental properties.
- New energy-efficient home design.
- Older homes that do not have air ducts.
- Supplemental heating and cooling to existing systems.