It is a direct expansion cycle (DX) that comprises of a Compressor, an Evaporator a Condenser and an Expansion Device. It uses refrigerant as a media to transfer unwanted energy (heat) from inside to outside (cooling) or from outside to inside (heating). In the system there is a reversing valve that changes the evaporator to a condenser and a condenser to an evaporator (hence the reverse cycle term).
Why refrigerant? Refrigerant is a chemical gas that changes phase from gas to liquid and visa versa. It is extremely energy efficient and can carry more the 50 times energy per weight than air and 10 times more than water. It boils at as low as -50°C (water +100°C) and condenses at as high as 140°C. These characteristic makes it suitable for most habitable areas of the world, smaller inter connecting pipes and compact and very cost effective.
The refrigerant safety class for domestic use MUST be A1 class non-flammable. There are other classes A2, A2L flammables and can be explosive under pressure and A3 highly flammable and explosive. Classes are as defined by ISO817 & ASHRAE 34 standards
The efficiency of cooling (EER) cycle or heating cycle (COP) can range anything between 250% (2.5/1) to 500% (5/1) (that is for every energy unit, say1 kW electricity consumed, up to 5 kW can be absorbed from inside (unwanted heat) to be rejected outside or absorbed from outside air or water or ground and transferred to inside to heat a house or domestic hot water).
There are mainly Air to Air (most common and cost effective), Water to Air & Water to Water systems. Systems can be compact (all components in one box) or Single Splits One indoor and One outdoor or Multi Splits where multiple indoor units connected to One outdoor unit.
The Indoor units can be a wall, floor, Ceiling or Ducted fan coils or a refrigerant to water heat exchanger to provide domestic hot water or medium temperature heating water for under floor heating or radiators. The interconnecting refrigeration pipe work would require specialist approved refrigeration engineers.
There are no extra safety control systems (provided the refrigerant is A1 class non-flammable) and no chimneys, extra builder’s work or electrical supplies.
Tel: 01483 478715