An Introduction to Multifamily Piping Systems
apartment repipe
This article is a basic introduction to these different kinds of piping systems used in multifamily residences. Heating, Ventilating and Air Conditioning (HVAC) HVAC systems can be categorized as either centralized or decentralized systems.

Centralized Systems Centralized systems heat or cool the entire building. Installation is more expensive than a decentralized system, but it offers a longer life. This is common in mid- to high-rise buildings . With this type of system, the cost of heating or cooling for a tenant is less variable and usually accounted for in rent costs. Decentralized Systems A decentralized system is one in which each unit in a building has its own separate system for heating and cooling. Maintenance for these types of operations is relatively inexpensive, but more frequent, as heating or cooling problems must be dealt with individually. This is often favored by low rise buildings because of lower installation cost. Water Supply Piping
Water supply piping includes potable water supply pipes, control valves, and a water pressure/drainage system. Potable Water Supply Pipes
Made from PVC, CPVP, PEX, copper, or galvanized steel, these are the pipes responsible for providing you with clean, drinkable water. Copper is a popular material used for these pipes, but over time the copper will degrade. There are potable water supply pipes to each unit in a multifamily building, and a properly installed filter can be used to avoid detrimental effects caused by the piping materials. Control Valves
Control valves in the individual units isolate water usage from each apartment unit, so that water consumption as well as possible damages to the system are isolated and do not spread through the entire building. Left unused, control valves will accumulate corrosive build-up. Waste Lines
A multifamily residence will typically have a single large drainage pipe that is connected to each unit for wastewater and human waste removal. This pipe must also be well ventilated to avoid a dangerous buildup in air pressure that could lead to burst pipes, and it should be checked for corrosion often. Residential multifamily piping is a complex subject involving many different systems that work together, but anyone who manages an apartment building or condo would be well advised to have a good understanding of multifamily piping in order to keep the systems operating at high capacity.