OS28 Specialised works categories

SOA category OS28

Heating and air-conditioning systems

OS28 covers heating and air-conditioning systems: supply, installation, maintenance and renovation of heating, air-conditioning and refrigeration systems. It ranges from domestic heat pumps to large office systems, through to industrial refrigeration and solar thermal. Together with OS3 and OS30, forms part of the general category OG11 Technological systems. It is a fast-growing qualification thanks to the EU Green Homes Directive and the energy transition.

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The scope of OS28: residential with heat pump, commercial with rooftop chiller, industrial refrigeration

SOA certification OS28: areas of application

OS28 covers all climate control in buildings, from heating to cooling. The main sectors:

Heating: condensing boilers, biomass generators, radiators, radiant floors and ceilings.
Air conditioning: split, multi-split, VRF systems, chillers and air handling units for offices.
Heat pumps: air-to-air, air-to-water, water-to-water and geothermal. It is the fastest-growing segment.
Solar thermal: panels for hot water and heating, also combined with heat pumps.
Refrigeration: cold rooms, supermarket plant rooms and cold-chain logistics, industrial processes.
Mechanical ventilation (MVHR): air exchange with heat recovery for homes, schools, offices and hospitals.
District heating and cogeneration: substations connected to urban networks and small cogeneration plants.
Regulation and control: automatic control and heat metering systems.

In short: OS28 is the category of all-round climate control, at the heart of the energy transition in the coming years.

Functional diagram of a residential air-to-water heat pump system: hot water cylinder, fan coil, underfloor heating coils

SOA categories related to OS28

OG11

Technological systems

groups together OS28, OS3 and OS30. Companies holding OG11 can carry out OS28 works in the same classification.

OS3

Water and sanitary systems, kitchens, laundries

deals with the building’s water network; OS28 with the production of heating and cooling. They often work together.

OS30

Internal electrical systems

brings the power supply to heat pumps, air handling units and control systems.

OS4

Electromechanical conveyor systems

works alongside OS28 in tall buildings, where machine rooms house systems of both categories.

OS5

Pneumatic and intruder alarm systems

borders on OS28 in pneumatic and central vacuum systems.

OG1

Civil and industrial buildings

is often the prevailing category in energy renovations: OG1 handles insulation and windows, OS28 replaces the generator and the system.

OG10

Electricity transformation systems

is needed when heating systems require dedicated electrical substations, as in data centres.

HVAC system of a commercial building: rooftop chiller, AHU, cooling tower, ductwork and room diffusers

Why it pays to qualify in OS28

OS28 is experiencing the biggest transformation in Italian building services in decades:
· the EU ‘Green Homes’ Directive calls for a reduction in energy consumption in residential buildings by 2030;
· demand is growing for heat pumps, ventilation and cooling for data centres and logistics.

If you install heating, air-conditioning, heat pump or refrigeration systems, OS28 opens up energy renovation contracts for schools, hospitals and public offices.

SOA category OS28: frequently asked questions

Download PDF technical data sheets

What is the official description of category OS28?

OS28 “concerns the supply, installation and maintenance or renovation of heating systems and air-conditioning systems, whatever their degree of importance, complete with all related masonry, complementary or ancillary works, to be carried out, separately from the execution of other systems, in general works that have already been completed or are under construction”. It therefore includes all heating, cooling, air-conditioning and refrigeration works, including building works strictly ancillary to the system.

What is the relationship between OS28 and OG11?

OG11 groups together OS28, OS3 and OS30. Companies holding OG11 in a classification can carry out OS28 works in the same classification. OS28 on its own is needed in contracts where the heating part prevails.

Is it better to qualify in OG11 or OS28?

OG11 suits companies that carry out all three types of system: plumbing, heating and electrical. OS28 on its own suits those specialised in heating.

Which works count as CEL for OS28?

Boiler rooms, heat pumps, air-conditioning systems, distribution networks (radiators, radiant floors), ventilation, refrigeration and solar thermal.

Does the Green Homes Directive require boilers to be replaced?

No. It sets consumption reduction targets for each country’s entire building stock, not obligations for individual owners.

Your next move?

Demonstrate your requirements and turn this knowledge into action: make sure you have the right SOA qualification and don’t hesitate to invest in training and innovation.