Pros and Cons of Ductless A/C and Heat Pumps
The pros of ductless systems:
- Ductless mini-split systems (air conditioners and heat pumps) are very energy efficient. Since mini splits have no ducts, they avoid the energy losses associated with ductwork of central forced air systems. Duct losses can account for more than 30% of energy consumption for space conditioning, especially if the ducts are in an unconditioned space such as an attic.
- The units are smaller than room air conditioners
- They are easier to install than other systems.
- In comparison to other add-on systems, mini-splits offer more flexibility in interior design options. The indoor air handlers can be suspended from a ceiling, mounted flush into a drop ceiling, or hung on a wall. Floor-standing models are also available. Most indoor units have profiles of about seven inches (~18 cm) deep and usually come with sleek, high-tech-looking jackets.
The cons of ductless systems are:
- The primary disadvantage of mini splits is their cost. Such systems cost about $1,500-$2,000 per ton (12,000 Btu per hour) of cooling capacity. This is about 30% more than central systems (not including ductwork) and may cost twice as much as window units of similar capacity.
- Qualified installers and service people for mini splits may not be easy to find. In addition, most conventional heating and cooling contractors have large investments in tools and training for sheet metal duct systems. They need to use (and charge for) these to earn a return on their investment, so they may not recommend ductless systems except where a ducted system would be difficult for them to install.
- Correct sizing of the system is important. Oversized or incorrectly located air-handlers often result in short-cycling, which wastes energy and does not provide proper temperature or humidity control. Too large a system is also more expensive to buy and operate.
The pros of Heat Pump systems:
- If you heat with electricity, a heat pump can trim the amount of electricity you use for heating by as much as 30%–40%, independent of the savings from the elimination of a ducted system.
- High-efficiency heat pumps also dehumidify better than standard central air conditioners, resulting in less energy usage and more cooling comfort in summer months.
The cons of Heat Pump systems:
- Heat pumps deliver relatively cool air during cold weather and cannot offset extremely high temperatures in summer.
- Heat pumps use more electricity than burner-based heating systems
- The energy efficiency benefits of heat pumps in the winter can be reduced if the cost of electricity is relatively high compared to gas or other combustible fuels.