Ductless systems are gaining in popularity across the nation, though many folks are still unclear about how they work, their advantages and other key questions. Following are some ductless heat pump FAQs that will fill in gaps in knowledge about these high-efficiency comfort systems.
Ductless Heat Pump FAQs
- What is a ductless heat pump?
Sometimes called a ductless mini-split, a ductless heat pump is a split-system air-source heat pump with one main distinction from regular air-source systems -- it doesn't use ductwork, hence the name. An outdoor compressor unit is connected to one or more indoor air-handling units with a conduit that carries lines for refrigerant, electricity and condensate. Each air-handling unit contains a coil and a fan, and delivers independently controlled heating or cooling to the room or small area where it's installed. Some ductless systems are purely A/Cs.
- How does the system work?
These units work similarly to regular air-source heat pumps, using refrigerant to transfer heat energy between inside and outside. In heating mode, the ductless heat pump removes heat energy from the outside air and brings it inside, where it's released from the coil in the air-handling unit, warming the air, which is blown into the room with the unit's fan.
In the summer, the ductless system works like an A/C, pulling heat from the room where the air-handler is installed and releasing it from the coil in the outside compressor unit. A reversing valve controls the direction of the refrigerant flow to match the desired mode of operation. Again, the lack of ducts, which frequently leak air and waste energy in forced-air systems, separates ductless heat pumps from traditional central heating and cooling systems.
- Do ductless heat pumps operate at the same capacity all the time?
Most modern ductless systems utilize variable-speed compressors using inverter technology to adjust their capacity to the heating or cooling needs at any given time. This enhances comfort while saving energy and avoids the frequent and noisy on-and-off cycling common in many air-source heat pump, A/C and furnace systems.
- How do you control a ductless system?
Modern ductless heat pumps come with independent temperature control in each area where an air-handling unit is installed. Many ductless systems can accommodate up to four or more air-handling units from one compressor unit, with each one equipped with a handy remote control. The remote controls often have programming capability.
- What situations are especially suited for ductless heat pump systems?
If you're adding a room or section onto your house, or perhaps renovating a porch or garage into a bedroom, a ductless system provides a practical and efficient option. With one of these systems, you won't have to pay to extend your home's ductwork, which may also run the risk of over-extending the central heating and cooling system. In homes without ducts, a ductless heat pump is a safe and efficient replacement for baseboard heating or combustion space-heating.
- Do ductless systems provide efficient heating and cooling?
As with any well-maintained heat pump system, ductless heat pumps can convert one unit of electricity into three of four units of heat output. This compares with a gas furnace, which no matter how advanced its technology, can't convert more than 99 percent of its fuel into heat.
For cooling, ductless systems use state-of-the-art technology to provide highly efficient air conditioning. Ductless heat pump efficiency is a result of the independent temperature control that allows you to turn off the heating or cooling to unused rooms or zones; the inverter technology that gradually adjusts output to match your needs; ultra-high efficiency ratings; and the absence of ducts with their air leakage and heat loss.
- Will ductless heat pump work in excessively cold weather?
In general, heat pump technology has one limiting factor – when temperatures fall below freezing, they struggle to extract enough heat from the outside air to provide comfortable indoor heating. Ductless technology, however, leads the industry in addressing this issue, and in recent years, ductless systems have steadily reduced the temperatures at which they'll operate efficiently. Modern systems are usually good for heating down to 14 degrees. When the temperature gets colder than that, a supplemental electric heat strip for emergency heating is a good idea.
We've barely scratched the surface with the above ductless heat pump FAQs. For more answers to your ductless heat pump FAQs, please contact us to find a certified Mitsubishi Electric contractornearby.