24 Volt Interface Kit for Mini-Split Systems and Hybrid Solutions

This kit is designed to enhance the operation of mini-split systems by making them act more like traditional systems. This kit also makes it possible to combine a mini-split system with a blower coil or furnace connected to traditional duct work in what is called a Hybrid System.

Controlling a Mini-Split System

Mini-Split systems can be connected to High Wall Heads, Ceiling Cassettes, Ducted units, Under Ceiling Units and Floor Consoles. The temperature control for all the indoor heads is located within the indoor unit. Because of this difference, homeowners need to be told what to expect when operating the equipment. Air likes to stratify into layers in your home; the coldest layer likes to sit on the floor and the hottest layer likes to touch the ceiling. 

The temperature in the room is regulated by the indoor head, so it is sometimes necessary to set the temperature higher or lower than expected to achieve the desired comfort level. For example, a ceiling cassette or under ceiling unit may need to have their temperature set 5-10 degrees higher to make the room comfortable. A floor console may need to be set 5-10 degrees lower to make the room comfortable. A ducted unit in a cold or hot attic may need to be set lower in the winter and higher in the summer to make up for duct leakage. Remember that the remote control and wired remote control are not thermostats but merely keyboards for entering information into the unit. 

If the homeowner doesn’t understand how to set the unit to make themselves comfortable, the 24V Interface kit is a good option. The 24V Interface will let you use most Five -Wire Standard Thermostats to make the equipment work like a conventional system; you can even use a Wi-Fi thermostat. 

It is always better to have this conversation before the equipment is installed so that you can determine whether a 24V Interface will be necessary or if the homeowner will be able to operate the equipment as is. The cost of the thermostat and 24V Interface should be figured into the cost of the installation. Many homeowners decide to get the 24V Interface even if they know how to operate a Mini-Split system because they like the additional system control the 24V Interface gives them.

Hybrid Solutions

Hybrid Solutions are a way of tying a Mini-Split to a blower coil and duct work, or a furnace, evaporator coil and duct work. The advantage of a Hybrid Solution is increased efficiency and reduced cost compared to a traditional heat pump system.

Details on the 24V Interface

Like most things in life there are features, benefits, and limitations to the 24V Interface.


  • AUTO Fan speed on Single Zone
  • Up to 3 Fan speeds on Single Zone Ductless Outdoor matched with Multifamily Fan Coils, and Furnace/Cased Coils applications.
  • One 24V INTERFACE KIT per indoor head.
  • Keeps the Inverter Compressor operating as a Variable Speed.
  • Auxiliary Heat control through the thermostat.
  • Diagnostic code display with LEDs.
  • 208/230V Transformer Built in.


  • Very efficient because of variable speed inverter drive.
  • Lower installation cost than traditional heat pumps with similar efficiencies.
  • Ultra quiet operation.
  • Can be used to heat or cool the whole house with an existing duct system.
  • The waterproof enclosure can be mounted outside or anywhere in-between the indoor and outdoor units.


  • Multi-Head units may need one 24V Interface/Indoor Head depending on equipment selected and size of rooms.  You will want an interface for relatively small rooms that have the potential to over condition due to minimum turn down and minimum five- minute runtime.
  • Each 24V Interface needs its own 5-wire thermostat; Standard Mini-Split Systems use conventional thermostats and Hybrid Solutions use a Heat Pump Thermostat.
  • Equipment cannot be randomly selected you must choose an approved equipment combination.  Equipment combinations and all things 24V Interface can be found in the Installation Instructions.

The 24V Interface is a great product that can enhance your Mini-Split Systems and satisfy the needs of the space and the homeowner.

Are you a homeowner or own a commercial property? Check out mybryantdealer.com to find a Bryant dealer near you!