We have put together a list of words and common phases into a glossary to try and help explain some of the technical differences and explanations: We can’t guarantee it is one hundred percent accurate but we think may help those people who are not familiar with how new renewable technologies are being installed and are becoming more popular by the day.

Unfortunately, the industry has done a good job in trying to confuse us all so we hope this helps.

Is generally a term used to explain the principal for extracting the energy from the outdoor air which is then processed via a chiller or aircon unit to transfer the energy into glycol, water or refrigerant via a sealed loop or pipework to the inside unit where the liquid passes through a coil (plate heat exchanger) to create hot or cold air which is then distributed and circulated by the fan via the central duct system.

Is the same principal as above but rather than converting air to air the energy is delivered via a traditional radiator wet system or underfloor heating which are both filled with water.

Buffer tanks are an easy way to make renewable energy projects even more efficient. In general terms, the stored water is maintained at a certain temperature which saves energy by eliminating the need to repeatedly heat water from cold and can provide instant hot water at source. The Buffer tank is often linked to an unvented cylinder when using an ASHP as spare capacity as you may not always have sufficient heat recovery time and you could run out of stored hot water.

The Central Duct, Header or Plenum are terms used to describe the galvanised metal or fibreglass duct that delivers the flow of air around the system. Plenum is generally a term used in the USA. Header is often used in the UK HVAC market

A chiller is a machine that removes heat from a liquid via a vapor-compression or absorption refrigeration cycle. This liquid can then be circulated through a heat exchanger to cool equipment, or another process stream. Most people associate a chiller to a traditional external air-con unit or fan used for air conditioning which are more commonly seen located on external walls on the outside of offices or commercial buildings. Chillers are also linked to split systems.

We use coils to transfer the heat into the flow of air. In the UK we would normally identify these as plate heat exchangers or coils.

The fan is used to circulate the flow of air over the coils and around the UNICO system via the central duct and tubing. In the UK we have selected to supply the ‘E’ type variable speed fans which are more energy efficient. In the USA the fan is more commonly known as the blower.

A hybrid (or dual fuel) heating system combines a traditional gas or oil boiler with a renewable heating system such as a heat pump for homes looking to replace their boiler with a more energy efficient and greener solution.

Is the control panel to connect the ASHP (air source heat pump) and the hot water cylinder to the UNICO system, underfloor heating circuit or traditional radiators.

Is often used to simplify the installation as the pre-plumbed cylinder incorporates all of the associated controls (brains) to ensure all the relevant components and appliances communicate effectively. This is the recommended and most used system. Having a Pre-plumbed indoor unit negates the need for a separate Hydro box and standard unvented cylinder.

Sits outside of the property and transfers energy inside. The energy is transferred from the outside unit and connected to the indoor unit using water filled copper pipes. The indoor unit is typically a pre-plumbed cylinder and associated controls or a Hydro box arrangement. A pre-plumbed indoor unit is the easiest and most straight forward option to avoid more complex wiring and commissioning. An air source heat pump is also a sealed unit which is primed with refrigerant but water is used outside the unit and therefore, these can be installed by a competent plumbing and heating engineer.

This tubing is used to take the air from the central duct and direct it to the outlets which are located in the living areas. The design and material used to make the tubing it critical to the system performance and noise level. Less than 30 decibels. It is important that these are not shortened for maximum performance.

Is generally where you have a sealed outdoor chiller / aircon unit filled with refrigerant which is then connected to an indoor unit / fan convector type product. Typically, these would have been connected together by pipework filled with refrigerant and therefore you would need the appropriate qualification to install this type of system. As technology has moved forward water is now being used to connect these units and therefore these can now be installed by a competent plumbing and heating engineer. The UNICO system can operate with either system by selecting the correct coil. Refrigerant if often to referred to as F-Gas.