Mainsystems

Mainsystems refers to the primary infrastructure networks that supply essential services to a building or site. They include energy supply, water, gas, climate control, waste removal, and communications infrastructure, as well as the physical routes and enclosures that carry these services. The term is used in building services engineering, facility management, and utility planning.

Key components are electrical mains and distribution, water supply mains and distribution, gas mains, heating, ventilation and air conditioning (HVAC) distribution, sewage and drainage, district cooling or heating lines if present, fire protection systems, and telecommunications and data cabling. Mainsystems also cover the spaces where services are routed, such as risers, shafts, and utility rooms.

In design, mainsystems are planned for reliability, safety, and efficiency, with attention to load requirements, redundancy, accessibility for maintenance, and compliance with local codes. They are often coordinated through a building management system and integrated with control and monitoring equipment.

Operation and maintenance involve regular inspections, leak and fault detection, valve isolation, calibration, and documentation. As-built drawings and asset registers support future upgrades and regulatory audits. Changes to any main system typically require permits and commissioning to verify performance.

The use of the term and the exact scope of mainsystems can vary by country and industry. In some contexts it refers primarily to electrical and utility services, while in others it encompasses broader infrastructure networks within a site.