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Frequently Asked Questions

If you are in the market for a new air conditioning or heating system — either to replace your current model or for a new construction project — you may have questions that need answers before you can make an informed decision. The information provided on this heating and air conditioning FAQ page will address several of the most commonly asked heater and air conditioner questions. We hope the answers we provide will help you better understand the factors involved in selecting, operating and maintaining your ductless system for maximum energy-efficiency.

Q: What, exactly, is a ductless AC system?

A: A ductless AC system is an energy-efficient heating and cooling solution that provides versatile indoor air conditioning without requiring standard HVAC ductwork to operate. Like a conventional ducted system, your ductless HVAC system can heat and/or cool multiple rooms in your home. This is sometimes referred to as zone heating and cooling.

The system consists of an outdoor unit (compressor) that is connected to one or more indoor units (evaporators) by refrigerant lines that run through a three- to four-inch hole in the outside wall. The number of indoor evaporator units used will depend on how many zones, or rooms, you need to heat or cool. Each outdoor compressor can operate up to four evaporators, letting you target the specific areas inside your home. When more than one indoor evaporator unit is used with a single outdoor compressor unit, the system is known as a ductless mini-split system.

Indoor units are attractively designed so they won't clash with your home décor. Units are typically installed high on one wall, though some models consist of a recessed ceiling unit. Free-standing floor units are also available for those who prefer them.

Q: Will a ductless AC system completely replace my current air conditioning system?

A: While your ductless AC system is intended to be used as your main air conditioning method, you may choose to hold on to your current system in case you should ever need additional, backup cooling. In particularly hot climates, or when weather conditions are extreme, some parts of your home may not be adequately cooled. Your ductless system can be used with zone or space heating and cooling equipment, heat pumps, and radiant floor heat.

Q: How does ductless air conditioning work?

A: Like a conventional heat pump, a ductless AC system provides both heating and cooling. Using similar reversible technology but without the need for ductwork or a separate indoor unit, ductless air conditioners move warm air indoors from outside when in heating mode and move warm air outdoors from inside when in cooling mode. They use like components as well, with each inside unit containing an evaporator and fan to treat and distribute the air and each outside unit consisting of a variable-speed compressor condensing coil, fan and expansion valve.

The cooling process:

  • Heat is moved to the outdoor unit from inside your home.
  • On its way back inside, the air is cooled by a refrigerant before it reaches the evaporator.
  • As it flows across the evaporator coils, the cooled air is delivered to the appropriate zone via a quiet fan.
  • The evaporator also works as a dehumidifier, making you more comfortable while allowing you to set your thermostat a few degrees higher during hot weather.

The heating process:

  • Air is drawn into the compressor from outside, then heated as it crosses the condensing coils.
  • To prevent system overheating, the condensing coils are kept cool by an internal system fan.
  • The heated air is transferred to the evaporators for distribution to each zone.
  • The system basically draws the warmth from the outdoor air and delivers it to the inside of your home.

Inverter technology built into the variable-speed compressors increases comfort by keeping indoor temperatures more uniform. This state-of-the-art technology also makes the system more energy-efficient while continuously monitoring and adjusting temperature, rather than controlling it through repeatedly cycling on and off, as conventional systems do.

Q: What type of control is used for a ductless air conditioning system?

A: Units can be operated either by wireless remote control or by a wall-mounted control unit. Remote controls that use batteries make it easy to control the system from anywhere within the zone. Ductless systems allow users to control a zone's precise temperature rather than limiting them to low, medium and high settings. Controls also feature the option of switching between heating and cooling mode, either remotely or by using the wall control. A number of programmable features are also built into the system's controls, including separate day and night settings that can provide greater convenience and greater energy savings.

Q: For what uses would a ductless system be appropriate?

A: Ductless systems are very versatile and have a wide range of uses. Discussing your needs with a trusted HVAC specialist can help you determine whether a ductless system is the right option for your home or business. This experienced professional can let you know whether your ceilings are high enough to install air ducts and your insulation sufficient for use with a conventional HVAC system or whether a ductless system would work better for your space.

The following are several situations that would warrant installing a new ductless AC system:

  • Building a new home: For new construction, homeowners will find that ductless systems offer a number of advantages and benefits, not the least of which is energy savings. Another key area of monetary savings results from not having to install ductwork in your new home. Your HVAC consultant can help you determine whether a single ductless system or multiple systems would better serve the various zones in your home. For two-story homes, ductless systems are generally superior since they are more effective than forced-air systems at heating and cooling the upper floors.
  • Upgrading your current outdated system: Ductless systems make a great deal of sense as replacements for older systems that are no longer efficient. The energy efficiency of ductless systems makes them a smart replacement for stoves, window air conditioners, space heaters and electric baseboard heaters.
  • Adding on to your home: Room additions often prove less costly when a ductless system is installed in the new room. Aside from removing the need to extend the ductwork to serve the new room, the ductless system will provide more energy-efficient heating and cooling for the room addition.
  • Converting an attic or basement: If you plan to convert these upper or lower parts of your home into living spaces, ductless heating and cooling will prove a practical, cost-effective and easy-to-install option.
  • Supplementing your zoned heating and cooling solution: Even if your zoned system is efficient, you may still need a bit of extra heating or cooling if some rooms aren't effectively served within a zone. A zoned system can work well to serve a single room, while a ductless system can be installed to serve the rest of the zone. When a building is not severely lacking but simply needs a minor climate-control boost, a single ductless system may be sufficient to provide the desired benefit.
  • Heating and cooling your summer home: If you own a second home that's used for only a few months a year, you may find it worth your while to install ductless air conditioning. This can help you avoid the necessity of ductwork upkeep and cleaning for a system you rarely use. At the same time, your ductless system will provide quick, convenient air conditioning during the months you use the home.

Q: How efficient are ductless AC systems?

A: Ductless systems have an excellent reputation for energy efficiency, using 25% to 50% less energy than central air conditioning systems. Because they use variable-speed compressors, zoned operation and duct-free performance, they use less energy than conventional systems. The consistently high SEER ratings ductless systems earn for air conditioning performance and the high HSPF ratings they earn for heating performance attest to the efficiency of these systems, with these ratings often far exceeding the minimum performance requirements for energy efficiency. Ductless system SEER ratings have exceeded 22, and the HSPF ratings on these systems have topped 10.

Ductless systems save energy in the following ways:

  • By not using air ducts, they eliminate the problem of leaky ducts and ductwork that is wrong size for the building. These issues can lead to energy losses of 30% or more. Because ductless systems deliver air directly to the room or zone, they can increase energy efficiency by 25%.
  • These systems eliminate the need to cool or heat rooms that are not being used. This can result in significant savings.
  • The variable-speed compressors that ductless systems feature make it possible for the system to remain on, with a variation in speed that helps maintain a consistent temperature taking the place of the continuous on-and-off cycling of conventional systems. This ensures more consistent climate control, rather than the temperature swings — from too hot to too cold — that characterize forced-air ducted systems. It also prevents the huge energy losses that occur each time the system switches on. Variable-speed ductless systems save energy by sensing when the system needs to run at a different speed to maintain a constant comfortable temperature.

Q: How long have ductless systems existed?

A: Ductless systems were developed in Japan in the 1970s. They were intended to be improvements on window air conditioners. The Japanese are well-known for their great respect for efficiency, so it's no surprise that they would have developed such a highly energy-efficient system — and one that made life more convenient by getting air conditioners out of windows and creating a quieter-running unit. It is said that necessity is the mother of invention, and in this case that was true. Because of severe restrictions on building that were commonly experienced in Asia, this innovative invention helped provide a badly needed climate control solution.

Soon, this innovative technology was embraced in North America, Europe and the rest of the developed world. As the natural evolution process brought new ideas to this segment of the industry, new features were added and improvements made, and a whole set of benefits emerged. System capacities increased, programmable controls were introduced, wider temperature ranges became feasible and distances that were possible between compressors and evaporators grew. Various types of ductless systems emerged — including mini- and multi-splits, bringing more versatility than single systems and accommodating a variety of building sizes and needs.

Q: How much does a ductless air conditioning system cost?

A: The price of a ductless AC system will vary based on manufacturer, model, system capacity and a number of other factors. Generally speaking, a ductless system can cost anywhere between $1500 and $5,000, depending on the area you need to cool and the energy efficiency of the specific product. Other factors that impact overall cost include how far refrigerant lines and copper tubing must be run to connect the indoor and outdoor units, the labor charges of the contractor you choose and the degree of complexity of your install.

Q: What incentives are available for ductless AC and heating systems?

A: Various incentives, such as tax credits and cash rebates, are available from state governments and HVAC manufacturers to reward consumers for making energy-efficient choices in heating and cooling products and installing these systems in their homes and businesses. Your location will determine which of these incentives are available to you. The internet is a helpful resource for locating the incentives that are available in your state.

Three types of incentives are described below:

  • Cash Rebates: Various utility companies offer cash rebates when consumers buy and install a ductless system, whether it's a completely new system or a replacement system/upgrade. Rebate amounts can be substantial, and residents who qualify may also be eligible for interest-free financing. Contact your local utility company for further information about the programs available in your area.
  • Federal Tax Credits: Business and residential customers may be eligible for specific business or personal federal income tax credits when they purchase and install qualifying energy-efficient HVAC equipment, including a ductless system. For help determining which systems qualify for the tax credit, contact your income tax professional and/or visit the Energy Star website. The Energy Star site will have the most accurate and up-to-date listings of the tax credits that were discontinued in 2012.
  • State Tax Credits: Different states' tax regulations will vary regarding credits and other incentives for purchasing energy-efficient HVAC equipment, so you'll need to check with your own state to find out which incentives might be available to you for purchasing a ductless system. Your state's Department of Energy may offer a residential or business energy tax credit. For information about the various state energy-efficiency incentives offered for purchasing a ductless system, visit the Database of State Incentives for Renewables and Efficiency.

Q: How long will a ductless system last?

A: Ductless heating and cooling systems will last for decades, providing home and business owners with dependable indoor comfort and convenient, cost-effective, energy-efficient operation. If you keep it well-maintained, your ductless air conditioning system should give you over 20 years of reliable service.

Q: How much maintenance does a ductless system require?

A: One of the most important items of routine maintenance a ductless heating and cooling system owner should perform is cleaning or changing the system's air filter once each month. Some systems offer washable filters, and others will require a filter change. Whichever type of filter your system uses, taking proper care of it will ensure that the dust, dirt, pollen and other allergens that become trapped in the filter are removed, providing better indoor air quality and more efficient system operation.

Another key maintenance task for your ductless system is cleaning the evaporator (indoor) and condenser (outdoor) coils once every season (four times a year) using a damp cloth. Periodically scheduling a system check and tune-up by an HVAC professional is also always a good idea. Conscientiously completing the maintenance activities described above should help your system function more efficiently, providing even more dependable service.

Q: How can I tell what size system to buy for my home?

A: Many different size systems are available to accommodate various customer needs and living spaces. Because the zones that each homeowner needs to heat and cool vary greatly, ductless systems are rated based on capacity, using a measurement known as a BTU rating, which helps a buyer estimate the size of the area the system can effectively heat or cool. Indoor unit BTU ratings can range anywhere from 9,000 to 30,000. If your home is large, you could potentially need more than one ductless system for adequate heating and cooling, or you might require another type of heating or cooling equipment to supplement your ductless system.

Because indoor and outdoor units each have a separate BTU rating, if you own a multiple-zone system you should carefully compare these capacities to ensure that the compressor can handle the combined capacities of all the evaporator units it will be required to run at the same time. This rule may be adjusted somewhat by ensuring that not all indoor units are running at maximum capacity at the same time.

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