VVS stands for heating, ventilation and sanitation and denotes both an industry in the construction industry and the technical systems in buildings that are planned, projected and executed by the industry, including the products that are then used. HVAC includes systems for water supply and sewerage in properties, as well as control and monitoring systems for this, as well as for control of the indoor climate. Important parts are energy supply with water-borne systems for heating and comfort cooling as well as distribution and drainage for tap water. Plumbing usually also includes systems for compressed air, gases in hospitals and industries, systems for fire protection with water sprinklers and more.
In the USA, the abbreviation is used HVAC (Heating, Ventilating, Air conditioning), dels plumbing for the two industries corresponding to plumbing. In the United Kingdom, the term "Building Services" is used, which also includes electrical installations. A term in Sweden that has become increasingly popular in the industry in recent years is installation technology. The word usually refers to both plumbing technology and electrical and telecommunications technology.
Various, relatively advanced technologies for heating, cooling and ventilation of buildings, as well as for water supply and drainage have long existed. However, the Romans took plumbing to a whole new level when they introduced their aqueducts and other structures that required the widespread use of lead pipes.  A clearly demarcated plumbing industry only emerged with the breakthrough of industrialism in the 19th century. The designation VVS was coined in 1930 through the magazine VVS, but only in the 1950s did it also become a designation for the technology and the industry.
The engineering companies in the industry (plumbing consultants) are traditionally focused on the entire plumbing area, but the contracting companies (installers) are divided into two sub-industries, ventilation contractors and pipe contractors.
Pipeline companies (gas, water, sewage) and thermal management companies (heating, ventilation) have existed since the middle of the 19th century, but were perceived until around 1914 to be two different industries. Subsequently, these two industries were merged into a common industry.
Modern ventilation technology has been around for a long time. During the 20th century, sheet metal warehouses or fan manufacturers made modern ventilation systems in industrial plants. During the 1950s, when ventilation installations began to become more extensive in office buildings and other premises and also homes, these also became a market for special ventilation contractors.
The workers in the pipeline companies were at first called "pipe workers" or "plumbers". In the early 20th century, the word plumber was launched. It was first Stockholm hose, but became an established professional designation around 1930. From the 1970s, the professional designations "pipe fitter" and "ventilation fitter", now often "plumbing fitter", were advocated.
HVAC technical systems
Housing has relatively simple systems. In premises, offices, larger retail premises, hospitals, etc., the systems for water and sewage are similar to for homes. But the systems for the indoor climate can be considerably more complex, and make up the largest part of a plumbing installation in a building. The installations for heating, cooling and ventilation are also closely linked and there are many different principle solutions.
For heating, radiators ("elements") are often used, which are normally placed under windows. In apartment buildings, they are connected via connecting cables (supply and return) to a trunk, which is often visible against the facade. The trunks connect to a main line in, for example, the basement corridor. There are valves for shutting down and adjusting the water flow. The main line goes on to the substation, which in an apartment building is now often connected to district heating. Other common heat sources are heat pump, boiler for pellets, wood, and oil.
In newer apartment buildings, the ventilation ducts are often in the same shaft as water and sewage. The ducts are pulled up to the attic and connected to an exhaust fan or to a unit with both supply and exhaust fans.
- Outdoor air = Clean air that is extracted from outside.
- Supply air = Heated / cooled air that serves the premises.
- Exhaust air = Return air that is often heat exchanged in the ventilation unit to give the house lower energy consumption, as air requires a lot of energy to be heated / cooled. . Passive house 
- Exhaust air = air which, after a heat exchange, leaves the system and the house.
Sanitation includes systems for handling liquids and gases, primarily installations for tap and waste water.
The water supply normally has three pipes, cold water (KV), hot water (VV) and hot water circulation (VVC), the latter to maintain the correct temperature of the hot water. If it did not exist, the temperature of the hot water would drop during the night. The pipes for KV, VV and VVC normally follow the heating pipes in, for example, the basement corridor in a pipe section, but the trunks are normally located in a slot near the kitchen or bathroom or laundry room. Valves for shut-off are available at incoming water meters (often located in the heating plant), at the trunk and where the trunk connects to the respective apartment. The wastewater pipes are located in the same slits and usually go down under the basement floor and are drawn horizontally in a collection pipe to the municipality's pipe, of course.
The plumbing industry
This article is not considered to be written from a global perspective.Feel free to help and improve the text if you can, or discuss the matter on the discussion page. (2016-12)
The plumbing industry is a large industry in the construction sector. There are about 1000 plumbing consulting companies and about 2000 plumbing contracting companies.
Swedish organizations include the industry organizations VVS Företagen, Plåtslageriernas Riksförbund / Entreprenörföretagen, Säker Vatten AB, VVS Fabrikanternas råd, Svenska rörgrossistföreningen VVS och Svensk Ventilation, and the personal association Energi- och Miljötekniska Föreningen.
In Sweden, there are two major industry magazines, VVS Forum and Energi & miljø.