There are several benefits to a ductless split system. For the contractor, installation is easier and more affordable, and the consumer has the availability of zone or spot heating and air conditioning.

Mitsubishi Electric says it has developed a way to make ductless heating and cooling more efficient while providing even more control for the customer.

The manufacturer is set to introduce its new MXZ30TN Multi-Evaporator Heat Pump Series that works with its MSH-TW/TN wall-mounted heat pump models. The MXZ is an outdoor multi-split heat pump system that can operate up to three indoor MSH wall units.

According to Michael Smith, marketing manager for Mitsubishi Electric’s Hvac Advanced Products Division, the MXZ will be the only heat pump system on the market with inverter technology.

“This is significant for Mitsubishi because it is the first 3:1 multi-evaporator heat pump product,” said Smith.

Multiple Choices

The wall-mounted heat pumps come in four different models in varying degrees of SEER and Btu capacity. The models start with the MSH09TW (providing about 10,500 Btu’s of heat in its single system design) and end with the MSH17TN (providing about 17,200 Btu’s of heat).

The indoor MSH models can be mixed and matched to correspond with the outdoor MXZ system. By doing this, more heating and cooling can be achieved, depending on the desire of the consumer. For example, by using three MSH09TW wall units with the MXZ, up to 29,150 cooling Btuh and up to 37,500 heating Btuh can be achieved.

For even more heating and cooling performance, the MXZ can be used with two MSH09TW wall units and the MSH12TN unit. This creates a maximum of up to 30,500 cooling Btuh or 38,000 heating Btuh.

These combinations can be changed around to match the specific needs of the homeowner or business owner with seven different possibilities. But the real benefit of the multi-evaporator heat pump is that three indoor wall units can be controlled and operated independently of one another. The indoor units can also be controlled with a wireless remote.

Mitsubishi's MXZ30TN multi-evaporator heat pump (right) can operate with three indoorMSH units (left.)

No More Stop and Go

“Our customers have really wanted this,” said Smith about the multi-evaporator system. “We’ve provided that and gone one step further with the inverter.”

The inverter technology, found in the MXZ system, is designed to allow for more consistent room temperatures. This technology controls the compressor rotation speed, which promotes temperature fluctuation detection, according to the company.

Smith says that with traditional rotary compressors, when a room gets too warm, the air will come on at full speed. With the inverter, says Smith, the room air conditioning is far more stable. It will control the compressor rotation in accordance with the cooling and heat load of a specific room. Some more conventional air conditioners and heaters repeatedly start and stop, causing rooms to be too warm or too cold. Sometimes these systems have trouble maintaining a consistent temperature. The inverter controls the rapid temperature variation, he explained.

Although the inverter helps to keep room heating and cooling consistent, it can also respond to temperature needs quickly. For example, according to Mitsubishi, the compressor rotation can be set at a speed 1.5 times faster than other models. When the temperature in the room must be raised, the inverter allows for that desired temperature to be reached more quickly.

“The biggest benefit of this system is that it offers high efficiency,” Smith said.

The inverter also controls the electrical current frequency to the compressor. The frequency is automatically lowered on inverter model air conditioners, lowering electricity consumption up to 30% compared to systems without an inverter.

Smith says that ductless systems and the MXZ system are a bit more expensive than traditional zone heating and air conditioning systems, but for a few hundred dollars more on installation, customers get the benefit of controlling specific rooms and areas of the home. Customers all have the benefit of the inverter technology, which can make optimum room temperatures easier to maintain.

But Smith says that for the extra price, the unit will end up paying for itself in the long run because of the reduction in energy costs.

For the contractor, Smith says there is the benefit of providing a more affordable alternative for customers. He also says that by installing a ductless system, a contractor cuts the amount of manpower and time needed in installing a regular system. This savings can then be passed on to the customer.

For more information, go to (website).

Publication date: 06/18/2001